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In order to improve the wear resistance of aluminum matrix composites and reduce the cost at the same time, the Al2O3/Al composite powder was prepared by hydrothermal method in this experiment, and the material properties of the Al2O3/Al metal matrix composite powder material were studied. It can be seen from the results that the encapsulation degree of Al2O3/Al-based composite powder material first increases and then decreases with the increase of ammonia concentration, and first increases and then decreases with the increase of PH value. The optimal molar ratio of salt and alkali is 1:1. Through the optimization of process parameters, the ratio of aluminum nitrate and ammonia water is obtained as: 1:1, the slurry stirring speed is 1500r/min, the stirring time is 10min, and the heating temperature is 200°C, the obtained composite powder is relatively uniform, has a larger specific surface area, and has better powder properties.

On the one hand, cermet has the advantages of metal materials, and on the other hand, it maintains the excellent properties of ceramic materials, and is a very important new engineering material. In this paper, the alumina/aluminum cermet material composite powder was prepared by ball milling, and its densification properties were characterized and studied to provide reference for the preparation of high-performance cermet materials. When the ball milling time is more than 6h, the distribution of alumina particles around the aluminum powder is relatively uniform. The research shows that: with the extension of the ball milling time, the number of pinning of Al2O3 particles on the surface of the Al ball first increases and then decreases; The trend of decreasing; with the increase of ball-to-powder ratio, the distribution of Al2O3 particles on the surface of Al balls is more uniform. Considering its cost-effectiveness, it is more suitable to prepare pinned alumina/aluminum-ceramic composite powder under the conditions of ball milling speed of 360r/min, ball-to-material ratio of 2:1 and ball milling time of 12h. When the Al content gradually decreased, the density and hardness of the cermet material also decreased gradually. When the Al content gradually decreased, the density and hardness of the cermet material also decreased gradually. When Al accounts for 75% in the sample, the microstructure is dense and the hardness is higher. When the molding pressure is 20MPa, the unevenness of the surface of the material is greatly relieved, relatively flat, and the densification effect is better. When the sintering temperature is 800°C, the fired sample is very dense, and the particles have relatively high bonding strength, but a small amount of aluminum is precipitated on the surface of the sample, forming a silver-white spherical substance.

China's coal resources are extremely rich, and the degree of coal mining is high. During the formation of coal, a large amount of coal gangue will be produced, which not only accumulates land and wastes resources, but may also cause natural disasters such as fires. In this paper, coal gangue is used as the main raw material, and a certain amount of kaolin, steel slag and other auxiliary materials are added to prepare coal gangue ceramsite through a high-temperature sintering process. The research results show that as the sintering temperature increases, the porosity of the ceramsite decreases first. After increasing, the water absorption rate of ceramsite also decreases first and then increases with the increase of the firing temperature, while the compressive strength first decreases and then increases with the increase of temperature. With the increase of the holding time, the porosity of the ceramsite first decreases and then increases. The water absorption rate of the ceramsite also first decreases and then increases with the increase of the firing temperature, while the compressive strength decreases first and then increases with the increase of the temperature. Elevated. With the increase of coal gangue content, the porosity of ceramsite gradually decreases, the water absorption rate of ceramsite also gradually decreases, and the compressive strength gradually increases with the increase of coal gangue content. The optimization can be obtained, the coal gangue content (mass fraction) is 100%, the calcination process system is 1200°C, and the heat preservation time is 60min as the better parameters. At this time, the compressive strength is 29.57MPa and the porosity is 4.36%.

With the popularization of electricity, the use of electric porcelain is becoming more and more extensive, but in the process of production, the waste of electric porcelain continues to accumulate and increase, which not only pollutes the environment but also affects the normal life of human beings. Therefore, it is urgent to deal with these electric porcelain wastes. In this paper, the electric ceramic waste is used as the main raw material, and starch and kaolin are added to optimize the formula to prepare porous ceramsite. The effects of the content of electrical ceramic waste, sintering temperature and holding time on the properties of porous ceramsite were studied. After research, the results show that with the increase of waste content, the porosity and water absorption first decrease and then increase, while the compressive strength first increases and then decreases. With the increase of the sintering temperature, the porosity and the water absorption rate decrease continuously at the beginning, and the compressive strength increases continuously at the beginning, but when the sintering temperature increases continuously, there will be a turning point or a flattening point. With the continuous extension of the holding time, the water absorption and porosity continue to increase, while the compressive strength continues to decrease, but the overall change is small. The optimization can be found that when the waste content is 75%, the sintering temperature is 1200 °C, and the holding time is 30 min, the prepared porous ceramsite has the best performance. Its water absorption rate: 13.87%, porosity: 27.52%, compressive strength: 20.06MPa.

With the popularization of "sponge city" in the whole country, the use of permeable bricks is increasing every year. Although the raw materials required for the preparation of permeable bricks are widely sourced, there are few reports on the process of using refractory waste to prepare permeable bricks. It is the ball milling process of refractory waste. The effects of ball milling time, ball mill rotation speed, and ball-to-material ratio on the properties of refractory waste were mainly studied. Through the experimental results and analysis, the following conclusions can be drawn: with the increase of ball milling time, ball milling speed and ball-to-material ratio, the particle size of refractory waste powder gradually decreases. Through research, it is concluded that the optimal ball milling time is 4h, the ball milling speed is 100r/min, and the ball-to-material ratio is 2:1.

In view of the low performance of porous ceramics on the wall, the heavy task of saving clay resources, and the major problems of dredging the Yangtze River, this thesis uses low-grade quartz sand along the Yangtze River as the main raw material and kaolin as the plasticizer. Drying, sintering and other processes prepare high-performance porous quartz ceramics, and improve the performance of porous quartz ceramics by studying the control conditions and the control mechanism related to the performance of the sintered body. Quartz porous ceramic bodies were sintered at 1100 °C and 1200 °C, and no obvious gradient structure was found. However, the quartz porous ceramic bodies had obvious gradient structures after sintering at 1300°C. The quartz porous ceramic bodies were sintered. When the temperature is 1400 °C, the green body is not found to have a pore gradient structure. When the water-to-material ratio is 1.2 and 1.3, the quartz porous ceramic body has no obvious gradient structure; when the water-to-material ratio is 1.4, 1.5, the sample has an obvious gradient structure. Combining the cost performance between material performance and energy consumption, in order to obtain a better bonding point, porous silica ceramics should be prepared with a water-to-material ratio of 1.4 and a sintering temperature of 1300 °C to prepare porous silica ceramics with a better pore gradient structure. Its porosity is 32.45%, and its compressive strength is 5.23 MPa.

As a kind of sponge city water-permeable material, permeable brick has good water permeability, chemical stability, corrosion resistance and weather resistance. Therefore, the development of permeable brick also broadens the engineering application market for its application. The discharge of a large amount of manganese slag will cause serious environmental pollution, and the problem of manganese tailings accumulation is serious. There is no ideal treatment method at present. In this paper, manganese tailings slag is used as the main raw material to prepare sponge city permeable bricks, thereby turning waste into treasure. Through research, the permeable brick with MgO used as sintering aid has very low compressive strength and good water permeability. CaO used as a sintering aid has high compressive strength and low water permeability. The porosity and water permeability of permeable bricks increase with the increase of CaCO3, but the compressive strength is opposite. In comparison, the permeable bricks prepared with three different sintering aids, 3% CaCO3 and 2% MgO as sintering aids have good water permeability and superior compressive strength. The permeability coefficient of the permeable brick prepared with 3%CaCO3 and 2%MgO as sintering aids is 2.0×10-2cm/s, and the compressive strength is 1.3MPa.

In this paper, the YAG powder is prepared by the co-precipitation method. In addition, the sintering aid to aid sintering and the high temperature foaming agent that becomes gas released during the heating process so that the sample has pores, the ball mill mixes the material, and the sample press is extruded. Box-type resistance furnace sintering. Through this process, porous ceramics can be made. Study the effect of sintering aid content, foaming agent type, sintering temperature on the properties of YAG porous materials. The analysis and discussion can lead to the following conclusions: as the content of sintering aid silica in the sample increases, the sintering temperature of the sample decreases. It is best when the ratio of sintering aid alumina to silica is 3:1. The moldability of the sample whose foaming agent is wood chips is worse than that of the sample whose foaming agent is fiber and carbon powder. The ratio of sintering aid alumina to silica is 3:1, and the sintering temperature of the sample with carbon powder as the blowing agent is best when the sintering temperature is 1400 °C.

At present, the commonly used cement has low tensile strength and low flexural strength, which is a fatal defect of cement materials. It is extremely urgent to conduct research on this shortcoming of cement. In addition, the steel industry steel mill produces a large amount of waste steel slag. The chemical composition of steel slag is similar to that of cement. This experiment makes full use of waste steel slag as raw material to prepare cement to improve the performance of cement materials. Using limestone, sandstone, shale, steel slag and river sand as the main raw materials, through the powder preparation, mixing, calcination, grinding, molding process and performance analysis of raw materials. After the calcination, the cement clinker in the form of a block becomes higher in hardness as the steel slag is incorporated. The higher the calcination temperature, the smaller the steel slag incorporation maximum. When the calcined at 1150 °C is mixed with 17.5% steel slag, a cement with better performance can be obtained.

Dye-sensitized solar cells have better development prospects than silicon cells, and their main structural composition of nanoporous semiconductor films is particularly important. It is the tin dioxide film, and the effect of preparing tin oxide film on dye-sensitized solar cells under different conditions is studied. In this paper, the SnO2 powder was prepared by hydrothermal method, and the experiment was studied by controlled variable method. The properties of the obtained tin dioxide powder were characterized by SEM and three-dimensional ultra-depth microscope and XRD. The XRD diffraction peak is shown as tetragonal phase rutile type SnO2, With the increase of the concentration of tin tetrachloride solution, the coarser the particle size of the tin oxide crystal in the film, the more complicated the surface morphology, so that the specific surface area of the film is larger. At 0.1 mol/L, the surface of the film is a porous structure in the form of a loose sheet is presented. After analyzing the surface microstructure and flatness of the tin dioxide film, it can be concluded that the effect of salt concentration on the specific surface area of the film is extremely large. When the salt concentration is higher or lower, the obtained two the surface of the tin oxide film is relatively flat and has poor performance. When the salt concentration is 0.1mol/L, the surface of the obtained film has a large undulation and a large specific surface area, and the ability to adsorb the dye molecules can be predicted to be the greatest, and the photoelectric conversion efficiency is optimal in the photocatalytic process.

Cermet is an important new engineering material that not only maintains the excellent properties of ceramic materials, but also has the advantages of metal materials. In this paper, the encapsulated alumina-aluminum composite powder was prepared by ball milling and characterized, which laid a foundation for the development of high properties cermet materials. Through the analysis of experimental results, the conclusions are shown when the ball milling time is greater than 3 h, the alumina particles are more evenly distributed around the aluminum powder. the ball milling for 6 h may have reached a limit of the mixing uniformity of the two powder, so the ball milling is determined 6 h as the better ball milling time. Under the ball milling condition of 50 r/min, the distribution of alumina particles around the aluminum powder is more uniform around the aluminum powder than the ball mill under 75 r/min, the ball milling speed is preferably 50 r/min. As the content of aluminum powder increases, the distribution of alumina in aluminum powder is large and uniform, and there is a small amount of pinning. It provides a package-like composite for the preparation of cermet with a wrapped structure and the thermal conduction mechanism of the controlled cermet.

Yttrium aluminum garnet is abbreviated as YAG, which has many excellent high temperature characteristics. YAG structural materials and functional materials are promising candidates. In this paper, YAG porous ceramic materials with different mechanical properties are prepared by adjusting the parameters of the sintering process to provide reference for the preparation of high-performance porous ceramics. From the experimental results, the following conclusions can be drawn: when the sintering temperature is 1450°C and the holding time is 2h, the YAG gradient porous ceramics have no deformation and shrinkage, have a regular good shape, and have good strength after sintering. The sintering rate was 8 °C/min and carbon emission temperature is 800°C, the structure of the YAG gradient porous material is good, the pores are uniform, and the strength of the sintered sample is high, The porosity is 25.7%, the compressive strength is 8.12MPa.

The effect of forming technology on the properties of quartz sand porous materials were researched with the low grade quartz sand along the Yangtze River via the pressureless sintering method in this paper, which lay technology foundation for researching new heat insulating materials. The wear of ball milling media is investigated through adjusting the ball milling parameter via the weigh methods. The results are shown that the porosity of quartz sand porous materials are decreased with increasing a forming pressure. The porosities of F30 and F50 materials are decreased with increasing a holding pressure time, however, the porosity decreasing rate of F30 is slower than that of F50. The porosity of F50 is higher than that of F30 under same forming conditions. Through optimized the forming conditions, the porosity of sintered F50 quartz matrix porous materials reaches 54.52% under the forming pressure for 5MPa and the holding pressure time for 5min.

In this paper, the effect of sintering temperature on the interfacial structure of the composite was investigated and three different formulation groups were used to compare the respective properties. To obtain a composite material with excellent interface, the law between reference number and performance is obtained. Through mixing, molding, sintering, sample preparation, scanning electron microscopic observation, energy spectrometer observation and analysis, the following conclusions can be drawn: As the temperature increases, the density and hardness increase. The sample melts at 1500 °C, and there is no specific data. When the temperature reaches 1450 °C, the density and hardness reach the highest. When the formulation is Fe:Al2O3:SiO2=18:1:1 and the temperature reaches 1450 °C, the properties of the sample materials are optimized. The density is as high as 95% and the hardness reaches 42.9HBW.

In this paper, the effect on the properties of alumina/aluminum cermet by changing the sintering temperature, and comparing the advantages and disadvantages of different characterization methods and their application range, it provides a reference for selecting the characterization technology suitable for alumina/aluminum composites.Through mixing, molding, sintering, sample preparation, scanning electron microscopic observation, energy spectrometer observation and analysis, the following conclusions can be drawn: the higher the vacuum sintering temperature, the more aluminum material is melted out of the body to form aluminum balls on the surface, and the green body The more severe the cracking. When the sample is sintered at a temperature of 600 °C, the density is the highest and the appearance is the best. When the molding pressure is 40 MPa and the sintering temperature is 700 °C, the microstructure of the sintered alumina/aluminum cermet is better. It can be seen from SEM and EDS analysis that the particles are continuously distributed and the larger one is metal Al, and the particles are discontinuously distributed and finer is Al2O3.

In this paper, the effect of raw materaisl on the properties of coated Al2O3/Al cermet materials were investigated, the raw materials were prepared via different methods, which provide a reference for obtaining higher performance cermet materials. Through mixing, molding, sintering, sample preparation, scanning electron microscopic observation, energy spectrometer observation and analysis, the following conclusions can be drawn, the density of the cermet material prepared by the mechanical ball milling method (83.5%) is higher than that of the cermet material prepared by the chemical precipitation method (92.8%). It is nearly 10% lower. The alumina particles prepared by the ball milling method are agglomerated, and a large amount of agglomeration occurs in the aluminum, and the composition is very uneven. For materials prepared by the precipitation method, the aluminum oxide is uniformly distributed in the aluminum. The ball-milling powder is used to prepare materials, most of the alumina is in the form of particles, and in the precipitation method. In the powder preparation sample, the thin layer of alumina which forms the same eggshell envelops the aluminum, and the aluminum has a certain liquid phase change. the surface hardness (824HV) of the cermet material prepared by the mechanical ball milling method is lower than the surface hardness (1005HV) of the cermet material prepared by the chemical precipitation method.

Both alumina and boron carbide have good hardness and strength, and are widely used in production and life, industrial manufacturing, and military defense. However, due to the insufficiency of research at this stage and the lack of technical means, it is difficult to prepare alumina-boron carbide composite powder with good coating and ultra high strength through large-scale batch production. Therefore, this experiment wants to obtain a relatively good performance of coated Al2O3/B4C cermet by hydrothermal method through different experimental parameter ratios. Through the experimental results and analysis, the following conclusions are obtained. The most suitable concentration of aluminum nitrate is 0.1 mol/l. The low concentration affects the formation of alumina particles. The concentration is too high and prone to agglomeration. Through the optimization of hydrothermal synthesis concentration, a composite of Al2O3/B4C composite with good nanoencapsulated structure was obtained. The composite powder was pure in composition and high in specific surface area, which lays a foundation for solving the low-temperature preparation of high-density boron carbide ceramics.

Nano-SnO2 is a relatively important semiconductor material. Its crystal structure is unique rutile type. It has the advantages of high conductivity, high transparency and stable chemical properties. It is widely used in gas sensing detectors and solar cells for photoelectric conversion. Applications. In this paper, SnO2 nanofilms with different crystal structures were prepared by changing the three process parameters of salt concentration, reaction time and hydrothermal temperature in hydrothermal method. The samples were tested by scanning electron microscopy (SEM) and three-dimensional ultra-depth microscopy analyzer. As the concentration of the reaction solution increases, the macroscopic thickness of the film gradually thickens, and the three-dimensional structure of the surface changes from flat to coarse to coarse peak. The peak between the peaks first increases and then decreases, and the surface microstructure is The conditions change are not obvious. Through the comprehensive comparison of film integrity and surface area, it is found that the concentration is 0.03mol/L, which is relatively better.

The construction industry continues to develop and the requirements for cement performance are getting higher and higher. At the same time, in the steel industry, the discharge of steel slag is also increasing. The effective reuse of steel slag has become a prominent problem in the steel industry. . Therefore, it is envisaged to use steel slag as a raw material for the cement production process to produce cement and to produce high-performance cement. The main raw materials of this experiment are steel slag, limestone, sandstone and shale. Through the cement preparation process, the cement is made, and then the cement is made into concrete to test its performance. This experiment mainly studies the sintering temperature and holding time variable. In the experimental test, the analysis and comparison were carried out in five aspects of the degree of macroscopic cracking, particle size, density, microstructure and composition. In the comparison experiment of sintering temperature, with the increase of temperature, the flexural and compressive properties of cement gradually increased. In this test, 1200 °C is the most suitable temperature for the performance of the cement. Through the experimental comparison of different holding time, it is known that with the prolonging of the holding time, the microstructure and actual performance of the cement are continuously enhanced. Comprehensive consideration: the ratio of steel slag in cement ratio is 10%, sintering temperature is 1200 °C, and heat preservation is 2h. The steel slag cement prepared under this condition has the strongest performance.

Dye-sensitized solar cells have better development prospects than silicon cells, and the main structural components of nanoporous semiconductor films are particularly important. In this experimental study, we used tin dioxide film and investigated the effect of preparing this film on dye-sensitized solar cells under different conditions. Furthermore, SnO2 powder was prepared through hydrothermal method, and an experiment was conducted through a controlled variable method. The properties of the obtained tin dioxide powder were characterized by SEM, 3D ultradepth microscopy, and XRD. An XRD peak is displayed as tetragonal-phase rutile-type SnO2, and the SEM indicates that the powder grain size is several nanometers. With the increase in reaction time, the film gradually became flat and uniform from only a small amount of powder coating. At the reaction time of 8 days, the integrity and flatness of the film were optimal, and the pore size was uniform. Moreover, the specific surface area was large. In summary, the reaction time of 8 days is suitable for membrane growth.

In this paper, the effect of raw materaisl on the properties of coated Al2O3/Al cermet materials were investigated, the raw materials were prepared via different methods, which provide a reference for obtaining higher performance cermet materials. Through mixing, molding, sintering, sample preparation, scanning electron microscopic observation, energy spectrometer observation and analysis, the following conclusions can be drawn, the density of the composite material increases first and then decreases with the increase of the molding pressure. When the molding pressure is 30 MPa, the density of the composite material reaches the maximum value, that is 93.5%. The greater the applied pressure, the more compact the aluminum powder and alumina powder, and the longer the tissue composition, the more uniform. there is no crack in the c-picture, and there are cracks in the a and b pictures. The microstructure of metal matrix composites prepared at different molding pressures is also different. Sintering of the green body formed at 30 MPa resulted in relatively few cracks and voids in the material. The surface hardness of the composite material increases first and then decreases with the increase of the molding pressure, and the surface hardness of the composite material reaches a maximum value (875 HV) at a molding pressure of 30 MPa.

YAG materials have a number of unique properties, the application is very extensive. In order to improving the properties of YAG porous materials, the effect of forming processing on the properties of YAG porous ceramics is investigated. Through the results and analysis, the conclusions showed that the porosity of YAG porous ceramics gradually decreased with the molding pressure increases, and the compressive strength of YAG porous ceramics shows a rising trend. The size and number of pores in the microstructure are reduced with increasing the forming pressure, there are inherently many voids in the YAG porous ceramics body at low forming pressures. The porosity of YAG porous ceramic decreases with the increase of dwell time, however, the process of extending from 5 min to 10 min is much faster than the rate of descending from 10 min to 15 min. The size and number of pores in the microstructure are reduced with extending the holding pressure time, which also makes YAG porous ceramics pose the higher mechanical strength. Through the analysis of the results, when the forming pressure is 10MPa, the porosity of YAG porous ceramics is 41.11% and the compressive strength is 5.8MPa, the porosity and compressive strength of YAG porous ceramics is better.

Ultrafine SnO2 is a new type of material, in the field of solar cells and semiconductors have a lot of use. To get different morphology and different properties of tin oxide powder material, making more applications in the field, the effect of the adjuvants on the properties of superfine SnO2 powders were distigated. Through the analysis of experimental results, the conclusions are shown the stronger the alkalinity of the auxiliary agent, the larger the grain size of the obtained particles and the more uniform the particles. When the molar ratio of salt to alkali is more than 1: 4, the amount of alkali is gradually reduced, the particle size is small, the morphology is not uniform and easy to agglomerate. When the molar ratio of salt to alkali is 1: 4, the smaller particle size is shown, the appearance morphology is uneven. The longer the reaction time, the more complete the grain, the more uniform the morphology. Under the condition of SnCl4 concentration of 0.05 mol/L, reaction time is 4 days, salt and alkali molar ratio is 1: 4, holding temperature is 200 °C, the auxiliary agent is NaOH, the size, shape and properties of synthesized SnO2 are the better.

A high-performance quartz sand insulation brick was prepared by using low grade quartz sand under different sintering process conditions. The optimum sintering process conditions were obtained by analyzing the relationship between microstructure and sintering process. Through the compounding, pulping, forming, drying and sintering processes, and the performance test of the porous brick, the following conclusions can be drawn, the comprehensive performance in all aspects, the porosity is similar, the preferred high compressive strength conditions, in order to get a best The bonding point, brick body sintering temperature of 1150 °C, porosity of 74.56%, compressive strength of 2.1 MPa of porous brick, and the pores are smooth, more uniform distribution. With the prolonging of the holding time, the porosity of the porous brick is reduced, and the performance is 1h, the porosity is 77.22% and the compressive strength is 2.05 MPa. When the raw material ratio is 60% quartz sand, 30wt% kaolin, calcium carbonate 9.6wt%, foaming agent 0.4wt%, water ratio 0.9 holding time at 1h sintering at 1150°C can get better porosity and compressive strength of the insulation brick. The porous material was sintered at 1150 °C, the content of foaming agent was 0.2wt%, the ratio of water to material was 0.9, and the compressive pressure and porosity were the better.

YAG has many excellent features and therefore has a wide range of applications. Preparation and properties of YAG porous ceramics via the casting method is investigated. Through analysis and discussion, the following conclusions can be obtained. With the increase of the content of foaming agent, in the foaming process of the slurry, bubbles generated by the foaming agent and water are gradually increased, the more pores are left in the body after casting, and when the blowing agent is too much, excessive bubbles are generated, which can lead to a very low strength of the green body and can not be formed and operated later. As the ratio of water to material increases, the porosity of the porous material increases. This is because when the blowing agent is constant, the amount of water required for foaming is constant, and the amount of foam generated is also constant. When the content of foaming agent and the ratio of water to material is both 1, the porosity and compressive strength is better.

The Al2O3/Al cermet composite powders were prepared via the ball milling method,which provide raw materials for preparing high performance cermet materials. The results show that the number of Al2O3 particles on the surface of Al particles increases first and then decreases with increasing the ball milling time and milling rotating speed. The number of Al2O3 particles on the surface of Al particles increases with increasing ball to powder mass ratio. The analysis of the ratio of performance to price shows that the better parameters for preparing the pinned Al2O3/Al cermet composite powders are as follows, the ball milling time 24h,the ball milling rotating speed 100 r/min and the ratio of ball to powder 1:2.

Cermet while maintaining the excellent properties of ceramic materials, but also have the advantages of a metal material, is an important new engineering materials. In this paper, Al-Al2O3 cermet is prepared using different molding process via the powder metallurgy method to study the properties of Al-Al2O3 cermet. The conclusions are shown the density of the initial and late increase is not obvious with the cermet body forming pressure increases, but the increase in density of 20-30MPa is more obvious. The density of the cermet material increases with prolonging holding pressure time is shown, the initial increase speed is faster, and the later growth rate becomes weaker. In the different molding pressure, the pressure is 40MPa and 15min, sintering temperature is 700°C and 1h, the sample density is 2.084g/cm3, the highest density, the best performance, aluminum and alumina distribution is the most uniform.

Ultrafine SnO2 is a new type of material, in the field of solar cells and semiconductors have a lot of use. To get different morphology and different properties of tin oxide powder material, making more applications in the field, the effect of the adjuvants on the properties of superfine SnO2 powders were distigated. Through the analysis of experimental results, the conclusions are shown the stronger the alkalinity of the auxiliary agent, the larger the grain size of the obtained particles and the more uniform the particles. When the molar ratio of salt to alkali is more than 1: 4, the amount of alkali is gradually reduced, the particle size is small, the morphology is not uniform and easy to agglomerate. When the molar ratio of salt to alkali is 1: 4, the smaller particle size is shown, the appearance morphology is uneven. The longer the reaction time, the more complete the grain, the more uniform the morphology. Under the condition of SnCl4 concentration of 0.05mol/L, reaction time is 4 days, salt and alkali molar ratio is 1: 4, holding temperature is 200°C, the auxiliary agent is NaOH, the size, shape and performance of synthesized SnO2 are the better.

To provide reference for optimizing the photoelectric conversion efficiency, we studied the effects of salt–alkali molar ratio on the properties of tin oxide nanofilms. We found that when the hydrothermal temperature was increased to 80 °C, the film growth was not complete. With a hydrothermal temperature of 120 °C, the film became more complete and structured. However, at 160 °C, thick and very irregular tin dioxide (SnO2) crystal particles were deposited on the FTO conductive glass surface. With the increase in heat treatment temperature, crystallization became more and more dense and complete. At 80 °C hydrothermal temperature, the simulated peak of the surface and number of peaks became smaller. However, they significantly increased with a hydrothermal temperature of 120 °C. When the hydrothermal temperature was at 160 °C, the surface simulated peak increased, but the number of peaks decreased. Moreover, the diameter of each peak was greatly increased. The film obtained via the hydrothermal method was relatively pure, and Sn(OH)3 was not completely converted into SnO2.

The YAM coatings on the ZrB2 composites surface were prepared by co-precipitation technique and with Al (NO3)3 and Y(NO3)3 solutions acting as precursor. The effect of matrix surface treating conditions, dipping times and calcination temperature was investigated. Phase compostion, coating morphology and interface between matrix and coating were analyzed by XRD and SEM. The results indicated that the YAM coating was formed after calcined at 1250°C in vaccum. The thickness of coating was increased with the dipping times, the smoothest coating was obtained by two dipping times, and matrix surface coarsing was beneficial for improving the adhension between matrix and coating. The ablative teste was evaluated at 2000°C by oxy-acetylene flame, the ablative properties was obviously improved by coating compared with uncoated composites.

Cermet while maintaining the excellent properties of ceramic materials, but also have the advantages of a metal material, is an important new engineering materials. In this paper, Al-Al2O3 cermet is prepared adding different sintering aids via the powder metallurgy method to study the properties of Al-Al2O3 cermet. The conclusions are shown the adding sintering aids can significantly improve the sintered density of Al-Al2O3 cermet. The sintering aiding effect of adding MgO is better than that of SiO2 and Y2O3, and the hardness and the strength of the sample are higher than those of samples with SiO2 and Y2O3, and the densification degree of Al-Al2O3 metal ceramic material is the best, the relative density is 94.8%, the surface hardness is 824HV. The flatness of the surface of the sample adding MgO shows that the bonding strength between aluminum powder and alumina powder is high. The prepared Al-Al2O3 cermet adding different sintering aids have higher density and fewer pores in the microstructure the prepared Al-Al2O3 cermet adding sintering aids has a package structure.

In atmospheric environments, Al2O3 ceramics have good oxidation resistance in water, acid, and other solutions and suitable corrosion medium resistance. Al2O3 ceramics is one of the most widely used engineering ceramics. In this paper, Al2O3/Al cermet matrix composites were prepared by mixing a series of powders with aluminum and alumina powders as raw materials. The interface of Al2O3/Al cermet was observed by scanning electron microscopy. The densification process of Al2O3/Al cermet was then explored from the aspects of formulation, molding pressure, holding time, and sintering process. After mixing and dry pressing, 50 wt% Al and 50 wt% Al2O3 were appropriate for sintering. Following sintering and measuring density, density was improved under 20 MPa with a 20-minute holding time. Through a comparison of the sintering process, the interface structure was observed via scanning electron microscopy, which found that secondary sintering is conducive to improving the density of Al2O3/Al cermet.

YAG materials have a number of unique properties, the application is very extensive, the burn is due to the temperature is too high or the residence time at high temperatures is caused. The undercurrent is the sintering temperature is too low or the holding time is not enough, resulting in product performance is too low or too small shrinkage. In this paper, the effect of sintering temperature on properties of YAG porous ceramics was investigated. The results showed that the firing temperature of the ingredients will be different and cause the same sintering process and sintering additives content of different samples burned. The increase in the content of SiO2 in the furnish with the sintering aid tends to occur. the effect of temperature on the mechanical properties of the samples after sintering was significant, so the raw materials include 60wt%YAG, 10wt% CaO, 10wt% SiO2 and 20wt% soluble starch, the molding process in 20MPa pressure 10min, the sintering at 1500°C for 2h, the sample porosity is 42.2%, the compressive strength is 5.8MPa, the outside shape is keep intact and the better pore microstructure is shown.

Dense 3Y-ZrO2 composite ceramics were prepared by using 3Y-ZrO2 nanopowders as the raw materials, via the process of ball milling, granulating, molding and calcination.We investigated the microstructure, surface morphologies, the mechanical property, the density and linear shrinkage rate of the sintered ceramics and the effect of the ball milling technics and the sintering technics on the above properties of the3Y-ZrO2 composite ceramics via SEM and testing. The results show that the most excellent technics in all was explored as follows: the ultrafine ball milling by adding zirconium balls of 2 mm at the speed of 35 r/min for 10 h, with the mass ratio of zirconium ball, water and mixed powders of 6:1:1, the granulaing with 1.5% PVA, the CIP, the pre-sintering to remove the organic substrate to 500°C and the microwave sintering from 20°C to 1450 °Cin 80 min in which the duration at 1450°C was 20 min and the natural cooling time of the samples was 90 min. And the 3Y-ZrO2 composite ceramics obtained by this process have a relative density of 99.2%, bending strength of 1098 MPa, and a fracture toughness of 7.8 MPa·m1/2.

Ultrafine Co2O3 powder was prepared via hydrothermal synthesis. The effect of technology on the performance of the superfine Co2O3 powders was investigated, and the hydrothermal parameters in preparing Co2O3 were gradually improved. In addition, the morphology and grain size of the Co2O3 powder were analyzed by FESEM. Results show that reducing the salt–alkali molar ratio resulted in more uniform Co2O3 powder and smaller particles, with average particle size of approximately 40 nm. Reaction time displayed little effect on the Co2O3 powder, but the particle size decreased with the reaction time. The concentration of salt solution remarkably affected the morphology of the Co2O3 powder. Lower concentration resulted in smaller particle aggregation and particle size.

YAG materials has a number of unique properties, the application is very extensive. In this paper, the superfine YAG powder materials were prepared by co-precipitation method and hydrothermal precipitation method. The influence of synthesis process on the morphology of the powder was investigated. The results showed that the precursor powder prepared via the co-precipitation method is mainly from amorphous to crystalline transition with the increasing calcination temperature, the precursor agglomeration is more serious, In the process of increasing the calcination temperature, the dispersibility of the roasted powder is greatly improved, which is favorable for the growth of the crystal grains, so that the particle size of the powder is gradually increased, the YAG precursor prepared by the co-precipitation method is transformed into YAG crystals, the phase transition occurs mainly between 900 and 1100°C. When the molar ratio of salt to alkali is Y3+: OH-=1: 8 via the hydrothermal reaction, the YAG particles with homogeneous morphology can be obtained. When the molar ratio of salt and alkali is increased continuously, the morphology of YAG particles is not obviously changed. The co-precipitation method is easy to control the particle size, the hydrothermal method is easy to control the particle morphology.

Cermet includes the excellent properties of ceramic materials and the advantages of metal materials, so it is an important new engineering material. In this paper, Al2O3-Al cermet is prepared using different molding process via the powder metallurgy method to study the properties of Al2O3-Al cermet. The conclusion are shown the increasing density of Al2O3-Al cermet is not obvious with increasing the forming pressure of cermet body during the initial and late processing, but the increasing density is more obvious under the forming pressure for 20-30MPa. The density of cermet materials are increased with prolonging holding pressure time, the initial increase speed is faster, and the later growth rate becomes weaker. When the molding pressure is 30MPa, the holding time is 10min, the sintering temperature is 900°C, the holding time is 1h, the prepared Al2O3-Al cermet adding sintering aids has a coated microstructure, which indicates that the large number of particles is migrated on the grain boundary. The sample density is 2.26g/cm3, the density is highest, the distribution of Al2O3 and Al phase is the most uniform. The buried sintering method is more suitable for the preparation of Al2O3-Al cermet composites than the nudity sintering method.

Given the shortage of energy reserves, new energy sources must be identified. In this regard, improving the efficiency of solar cell conversion and simplifying the solar cell technology have become the focus of research. In this study, tin oxide nanometer thin film was fabricated on FTO conductive glass as photocathode through hydrothermal method. The synthesis condition was regulated, and performance test was also conducted. Results show that the crystallization driving force, crystallization rate, and grain size of tin dioxide crystal increase with increasing alkali ratio, leading to disorganized accumulation of tin oxide. Under prolonged holding time, tin oxide crystal became complete, and the surface area of the crystal increased. The crystallization driving force and rate also increased with increasing salt concentration and accompanied by clutter of tin oxide. The optimized process condition included 1:4 molar ratio of salt to alkali, 0.05 mol/L salt concentration, 200 °C reaction temperature, and 8 days of reaction. The highest specific surface area of the tin oxide nanometer film was obtained under the optimized condition.

In order which aim to save land resource and use low grade nature resource to realize high cost performance product. In this paper, the molding method of quartz sand fired brick is discussed. As the plastic (hand pressing) is only used to manually beat the mud mass, the sludge is squeezed by hand. Into the mold and molding and cold isostatic pressure molding pressure of 100 MPa, The difference is far away, which makes the gaps between the particles close to each other greatly different, the pressure of hand-press molding is small, the voids in the blank after molding are large and the hole diameter is large, and the green compact density of the brick body is small. The compact densities of the 65MPa and 150MPa pressed brick bodies are all lower than 100MPa, but 150MPa is still denser than 65MPa. The compressive strength is first increased and then decreased with increasing the molding pressure, when the pressure is 100 MPa, the maximum compressive strength is achieved at 100 MPa achieves the highest point.

This work investigated the effects of molar ratio of salt to alkali on the properties of tin oxide nanofilms to provide reference for optimizing its photoelectric conversion efficiency. The tin oxide film grown by hydrothermal method exhibited poor film-forming property. The macroscopic analysis revealed the formation of a thick film. The bonding force to the FTO substrate was poor, its brittle, and easy to fall off. When the molar ratio of salt to alkali was 1:8, the tin oxide film exhibited improved microstructure and large specific surface area, which could benefit electron transport. Moreover, the film showed excellent photoelectric conversion performance. However, mechanical properties, such as adhesion between the tin oxide film and the conductive glass FTO, remain to be improved.

Alumina ceramics with good mechanical and corrosion resistance are the ones of the most widely used engineering ceramics. The aluminum has high strength, high conductivity and high plasticity etc. so that aluminum ceramics are used in more and more industries. In this paper, the mass fraction of 25% Al2O3 powder and the mass fraction of 75% Al powder were mixed in the blender. Mixer speed is100r/min with mixing time of 3.5 h. Forming, sintering and a series of processes for preparing the alumina/aluminum metallic ceramic materials, through performance testing and analysis, found that the density of the sample firstly increased and then decreased with the increase of sintering temperature. A melting point is close to the sintering temperature and the density of the cermet can be made relatively high. When the sintering temperature is about 600°C and 700°C, the macro performance of sample is better. The cermet is sintered at 700°C and its microstructure is relatively better.

YAG materials has a number of unique properties, the application is very extensive. In this paper, the superfine YAG powder materials were prepared by hydrothermal precipitation method. The influence of synthesis process on the morphology of the powder was investigated. The results showed that when the molar ratio of salt to alkali that Y3+: OH- is 1:8, the more uniform morphology of the particles can be prepared, when the molar ratio of salt to alkali is increased, the morphology of the particles will not change. The reaction time is longer, the particle size will be thicker. The smaller the concentration of Y3+ ions is, the larger the particle size will be small. The experimental results show that the rod-like particles have a poly-crystal structure at the reaction temperature of 200°C, reaction time of 2 days and the molar ratio of salt to alkali of 1:8. The diameter of the rod-like particles is most of the powders have a particle size of 1000 nm and a small amount of powder has a particle size of about 5000 nm. The purity of powder is higher through the test of XRD.

The sintering methods of quartz sand porous ceramics were researched with the low grade quartz sand along the Yangtze River via the vacuum sintering method in this paper, which lay technology foundation for researching new heat insulating materials. The quartz porous ceramics is obtained with the high performance cost, the quartz porous ceramics is sintered at 1050°C via the vacuum conditions, the density of ceramics is 1.267g/cm3, the porosity is 51.6%, the compressive strength is 3.184MPa, the porous ceramics show the homogeneous distribution micro-pore and good shape. The density and the compressive strength of prepared ceramics via the vacuum sintering both are higher than that of prepared ceramics via the atmosphere sintering, however, the porosity is shown the opposite results.

Zirconium diboride is widely applied because of some excellent performances. The oxidation kinetics of ZrB2-YAG-Al2O3 composite materials were researched, which helps to improve the performance of ultra-high-temperature composite materials. The results show the oxidation weight gain is decreased with increasing the content of YAG-Al2O3 and the molar ratio of Al2O3. The oxidation weight gain is increased with prolonging the oxidation time under 1300°Cæ, the oxidation weight gain ratio is decreased with prolonging the oxidation time. The effecting tendency of oxidation weight gain is not abvious with varying the contend of YAG-Al2O3 upon 1300°Cæ, however, the effecting tendency of oxidation weight gain is very abvious with varying the molar ratio of Al2O3.

The composite ZrB2 powder coated A12O3-Y2O3 prepared by co-precipitation method were densified via the spark plasma sintering (SPS) and then researched the oxidation resistance at high temperature. ZrB2 powder must have the better dispersibility during the coating processing for obtaining the better coating effect. Effect of dispersant on the dispersibility of ZrB2 powder in the liquid is researched in this paper, the results show ZrB2 powder have the better dispersibility as the dispersant for PMAA and the content for 2vol%, which lay foundation for synthsising the better coating effect coated A12O3-Y2O3-ZrB2 composite powder.

Cermet materials is a important new engineering materials with the advantages of ceramics and metal materials. The Al2O3/Al cermet materials is prepared via the powder metallurgy method, the effect of sintering technology on properties of Al2O3/Al cermet materials is researched in this paper, which lay the base for preparing the high performance cermet materials. The results are shown through the study, the denstity of cermet is increased with an increasing moliding pressure, the sample density is 2.084g/cm3 as the pressure for 40MPa and the sintering temperature at 600¡æ, the density is higher, that is to say it is highest performance, the distribution of aluminum and alumina is most uniform. When the sintering temperature is higher, howerver, the molding pressure is lower, the lower density of the sample is shown, the aluminum is easier to overflow the surface of the sample.

Cermet while maintaining the excellent properties of ceramic materials, but also have the advantages of a metal material, is an important new engineering materials. In this paper, prepared by calcination of alumina - aluminum metal-ceramic composite material powder, and its characterization as a basis to provide raw materials for preparing high performance metal ceramic material. According to the research, with the calcination temperature is increased, the rate of change gradually increase the weight of aluminum. Calcined at a temperature of 600¡æ, the oxidation of aluminum surface the best. With the firing time increases, the rate of change in the weight of aluminum powder showed an increasing trend. When 8h, oxidation of aluminum surface better. Through this experiment, process optimization can be found in the calcination temperature was 600¡æ, calcination time is 8h, the best coating effect aluminum surface, coating evenly, clean interface, the reaction layer thickness of about 700nm, the prepared package type composite powders the best results.

Yttrium aluminum garnet (YAG) with a chemical composition of Y3Al5O12 is an important advanced structural and functional material due to some excellent properties. The porous YAG ceramics were prepared via vacuum sintering technology, the effect of sintering aids on the properties of porous YAG ceramics were investigated in this paper. Through an analysis and discussion, the conclusions are that the porosity increases with the increasing sintering temperature from 1300°C to 1500°C, the pore is moved to the surface of sample, which forms the open pore to make the porosity increase, the more and bigger sintering neck is increased. Porous YAG ceramics are sintered at 1500°C, the regular outside shapes of porous YAG ceramic are kept using CaO and MgO as sintering aids, the outside shape of porous YAG ceramic is wrecked using Al2O3 as sintering aids, which shows the over fired phenomenon.

The technology of quartz pore gradient ceramics were researched with the low grade quartz sand along the Yangtze River via the vacuum sintering method in this paper, which lay technology foundation for exploiting new heat insulating materials. The research results are shown as following, when the ratio of water to raw materials is 1, the shape and pore distribution of pore gradient ceramics is better. The porosity are first increased and then decreased with an increasing the sintering temperature. The suitable sintering temperature is decided at 1100°Cæ, the density is 1.343g/cm3, the porosity is 48.7%, the compressive strength is 7.071MPa, and the pore gradient structure is homogeneous transition zone.

Metal ceramics are a important new engineering materials with the advantages of ceramics and metal materials. The Al-Al2O3 metal ceramics were prepared via the powder metallurgy methods and characterized in this paper, which lay the base for preparing the high performance cermet materials. Through the results and analysis, the conclusions are shown that the relative density is increased with a increasing forming pressure, the electrical resistivity is decreased with a increasing forming pressure. The relative density is increased with a increasing sintering temperature under 700°C, the relative density decreases with a increasing sintering temperature above 700°C, the electrical resistivity is shown the opposite tendency. Through the optimizing the technological parameter, such as the sintering temperature at 700°C, the forming pressure under 20MPa, the Al content for 75wt%, Al-Al2O3 metal ceramics are successfully prepared with the high relative density and the low electrical resistivity, the relative density is 97.52%, and the electrical resistivity is 101.34Ω·m