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This study investigated the effect of adding La–Ce mixed rare earths and Sr on the microstructure and mechanical properties of AlSi10MnMg alloy. The experiment utilized different combinations of modifiers, including single La–Ce rare earths, single Sr, and the combined addition of La–Ce mixed rare earths and Sr. This study compared their effects on grain refinement, the modification of the α-Al phase and eutectic silicon phase, and tensile properties and hardness. The results showed that the combined modification of Sr and mixed rare earth elements significantly refined the grains, optimized the morphology of the α-Al phase and eutectic silicon phase, and improved the overall mechanical properties of the aluminum alloy. Under the combined modification, the addition of 0.02 wt.% Sr and 0.1 wt.% RE (La–Ce mixed rare earths) exhibited the most pronounced refining effect. The secondary dendrite arm spacing (SDAS) was reduced by 59.18%. The eutectic silicon phase transformed from coarse needle-like shapes to fine fibrous or granular forms, with an aspect ratio reduction of 69.39%. Meanwhile, the alloy's tensile strength and hardness were significantly improved. The tensile strength increased to 240 MPa, achieving an increase of 23.08%; the yield strength increased to 111 MPa, achieving an increase of 18.09%; and the elongation reached 7.3%, achieving an increase of 73.81%. This indicates that the proper addition of Sr and mixed rare earths can significantly optimize the microstructure and enhance the mechanical properties of AlSi10MnMg alloy, providing an effective method for the preparation of high-performance heat-treatment-free aluminum alloys. [ABSTRACT FROM AUTHOR]

The study involves in-situ synthesis of CrFeAlTi composite coating using laser micro-melting processing. The coating was successfully prepared by laser irradiating CrFeAlTi coating prepared by flame spraying on the China low activation martensitic (CLAM) steel substrate, and then Al2O3-TiO2 composite ceramic coating was synthesized by in-situ reaction on the surface of flame sprayed coating. The coating morphology, microstructure, phase composition, micro-hardness, dry sliding wear properties and corrosion resistance in liquid PbBi alloy were analyzed by stereomicroscope, scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), micro-sclerometer, vertical universal friction wear testing machine and static PbBi corrosion test device, respectively. The test results show that the surface of Al2O3-TiO2 composite ceramic coating is smooth, and the microstructure of coating is both homogeneous and dense without defects such as crack, dimple and porosity, etc., a good metallurgical bonding between the composite ceramic coating and the substrate, and the interface is obvious. The phases of the coating surface are mainly composed of Al2O3, TiO2, (Al.948Cr.052)2O3, Fe2TiO5 and FeCr, etc. The coating shows a high average micro-hardness of approximately 1864.2HV0.2, which is about three times higher than that of the CLAM steel substrate, and presents gradient distribution with stable transition from the coating surface to the substrate. Comparing with the substrate, the coating presents excellent wear resistance. The wear mass loss of the coating is just one sixth of that of the substrate. Meanwhile, the coating exhibits the best corrosion resistance in the liquid PbBi.

In this study, the effect of different Ca additives (Ca(OH)2, CaO, and nano‐CaCO3) on the composition and microstructure of the fused BaZrO3 crucible were investigated, as well as their interaction with Ti2Ni alloy during vacuum induction melting. Results showed that the crucibles had the same phase compositions when the doping amounts of Ca additives were the same. Three kinds of Ca additives provided three different grain sizes of CaO precursors to participate in the solid solution reaction. When the doping amount of the Ca additive was 5.3 wt.%, the ZrO2 phase in the fused BaZrO3 was disappeared, and the CaZrO3 phase was founded. The composition of the crucibles doped with 7.7 wt.% Ca additives only consisted of Ba1‐xCaxZrO3 and CaZrO3 phase. The relative densities and erosion resistance of the crucibles were improved effectively with the increase of Ca additive content. Moreover, the crucible doped with 7.7 wt.% nano‐CaCO3 additive exhibited the highest density and the thinnest erosion layer. The Ba1‐xCaxZrO3 and CaZrO3 phases were dissolved by the alloy melt, according to the interaction analysis. In addition, the crucible doped with nano‐CaCO3 additive had a higher content of refractory element concentration in the alloy melts in comparision with the other two kinds of crucibles due to their higher number of pores. [ABSTRACT FROM AUTHOR]

A nanoflower structure of Zn 0. 7 6 Co 0. 2 4 S directly grown on carbon fiber papers (CFP) was successfully designed by a mild two-step hydrothermal method. Benefiting from their fascinating structural features, Zn 0. 7 6 Co 0. 2 4 S/CFP electrode exhibits a maximum specific capacitance of 300 F g − 1 at current density of 1 A g − 1 and 84% capacitance retention after 5,000 cycles at current density of 5 A g − 1 . Subsequently, Zn 0. 7 6 Co 0. 2 4 S/CFP//AC all-solid-state asymmetric supercapacitor (ASC) device is assembled and able to illuminate the red LEDs. ASC devices deliver a maximum energy density of 9.59 W h kg − 1 at a power density of 750 W kg − 1 . Therefore, this impressive result demonstrates that the nanoflower Zn 0. 7 6 Co 0. 2 4 S have promising applications in the development of high-performance supercapacitors. Zn0.76Co0.24S/CFP was obtained using two-step hydrothermal method. Its microstructure presents a novel nanoflower arrays. The synergistic effect between Zn0.76Co0.24S nanoflower and CFP improves the electrons transport efficiency, conductivity and structural stability of the hybrid. The as-prepared Zn0.76Co0.24S/CFP electrode delivers a specific capacitances of 300 F g−1 and exhibits an excellent cycling stability (retaining 84% after 5000 cycles) as well as a high energy density of 9.59 W h kg−1. [ABSTRACT FROM AUTHOR]

This study explored the effect of Cr 3 C 2 content (0, 0.5, 1, 1.5, and 2 mol%) on the microstructure, magnetic properties and mechanical behavior of TiC–10TiN–6WC–4C–(15,30) Ni (mol%) cermets after vacuum sintering. The results show that just Ti-based carbonitride ceramic grains and Ni-based binder phase were presented in the experimental cermets, and the mean size of ceramic grains reduced with the increase of Cr 3 C 2 content. By adding Cr 3 C 2 into cermets, the Cr concentration in binder phase obviously raised. However, Ti concentration in binder phase decreased continuously as Cr 3 C 2 content increased, while the W concentration remained nearly constant. Saturation magnetization and remanence of cermets decreased with increasing Cr 3 C 2 content, which was primarily ascribed to the increased amounts of antiferromagnetic Cr element in the Ni-based binder phase. When Cr 3 C 2 content exceeded 0.5 mol%, cermets became paramagnetic at room temperature. Cermets with 15 and 30 mol% Ni had Curie temperatures of roughly 138 K and 28 K by 2 mol% Cr 3 C 2 addition, respectively. Therefore, Cr 3 C 2 addition is very effective in suppressing the ferromagnetism of cermets. Moreover, transverse rupture strength and hardness of cermets first raised and then declined with the addition of Cr 3 C 2. • Increasing Cr 3 C 2 addition reduced the RT magnetization of cermets. • Ferromagnetic state of cermets at RT disappeared at x ≥ 1. • Curie temperature as low as 28 K was achieved in cermets. • Hardness of non-magnetic cermets with 1 mol% Cr 3 C 2 was about 91.9 HRA for y = 15 and 89.0 HRA for y = 30. [ABSTRACT FROM AUTHOR]

This study analyzed the influence of cooking temperature (60, 70 or 80 °C) and time (2, 6, 12 or 24 h) on the quality of duck meat cooked in sous vide method. Cooking loss, color, texture, microstructure, flavor profile and lipid oxidation were investigated. Temperature and time affected quality properties. As cooking temperature increased, the values of cooking loss, yellowness, adhesiveness increased; but the values of lightness, redness, hardness decreased. Increasing cooking time led to higher cooking loss, yellowness and lower lightness, redness, hardness, springiness, chewiness. Texture and microstructure results showed the mild treatment in sous vide cooking provided tender meat. The flavor profile of duck meat was evaluated by sensory analysis, gas chromatography-mass spectrometry (GC-MS) and odor activity values (OAVs). Sensory results indicated that samples cooked at moderate conditions (70 °C for 6 or 12 h) showed better sensory characteristic with higher meaty, fatty and umami note. The volatile compounds reached the highest concentration in duck meat cooked at 70 °C for 6 h and then followed by 70 °C for 12 h. Of these, 14 odor-active compounds with OAVs ≥1 were the main contributors to the overall aroma of duck meat. The OAVs of hexanal, heptanal, octanal, (E)-2-octenal, nonanal, cis-4-decenal, decanal, (E,E)-2,4-nonadienal, 2,4-decadienal, (E,E)-2,4-decadienal and 1-octen-3-ol in samples cooked at 70 °C for 6 h or 12 h were relatively higher than other samples. Therefore, it was suggested that moderate cooking temperature-time combination would produce better flavor characteristic and texture quality of duck meat in sous vide method. [Display omitted] • Cooking temperature and time affected quality properties of sous vide cooked duck meat. • Mild cooking conditions led to better sensory scores and higher content of volatiles. • 14 odor-active compounds with OAVs ≥1 contributed to the overall aroma of duck meat. • Longer cooking time (24 h) reduced the eating quality of sous vide cooked duck meat. [ABSTRACT FROM AUTHOR]

To meet the demand for efficient and reliable copper and aluminum (Cu/Al) joints in refrigeration and electric power industries, interfacial reactions in 3003 Al/T2 Cu and 1035 Al/T2 Cu joints brazed by Zn-xAl (x ranged from 2–25 wt.%) filler metals and their effects on the mechanical properties of the joints were investigated. Microstructures and fracture surfaces were observed combining with composition analysis. For 3003 Al/Cu joints, bulk CuAl and CuAl2 intermetallic compound (IMC) formed in brazing seams, and a CuAl IMC layer formed at the Cu side interfaces. For 1035 Al/Cu joints, bulk CuAl2 IMC formed in brazing seams, and an Al4.2Cu3.2Zn0.7 IMC layer formed at the Cu side interfaces. For both kinds of joints, shear strength increased first, then decreased with the increasing Al content. The increase in shear strength was because Al promoted the formation of Cu-Al IMC, and caused dispersion strengthening. With the excessive Al content, however, the bulk IMC became coarse and the IMC layers at Cu side interfaces grew thick, causing the joint strength to decrease due to stress concentration. The strength of 3003 Al/Cu joints was always higher than that of 1035 Al/Cu, and their highest strength were achieved by Zn-12Al and Zn-15Al, respectively. [ABSTRACT FROM AUTHOR]

In this study, a type of red mud/slag-based cenospheres/geopolymer foam was directly fabricated using the direct foaming method at room temperature. The effects of high-temperature exposure (700–1100 °C) on the phase evolution, pore structure, and properties of the foams were investigated. The results showed that the untreated foam was amorphous structure. The porosity of the foams increased from 36.4 ± 0.6% (1 wt%) to 71.9 ± 0.1% (5 wt%) with the addition of H 2 O 2. The compressive strength of the foams was 1.20–18.15 MPa, which was attributed to the good bond between the cenospheres and red mud/slag-based geopolymer matrix, the fractured spheres, and the crack deflection. After this high-temperature exposure, the foam crystallized mainly into the leucite and mullite phases. The density and compressive strength of the foams decreased as the exposure temperature increased. The thermal conductivity of the foams reached the lowest value of 0.169 W/(m⋅K) and 0.108 W/(m⋅K) with 5 wt% H 2 O 2 before and after the exposure, respectively. These foams have demonstrated good potential for application in the building insulation field. [ABSTRACT FROM AUTHOR]

(Ti 1-x W x )C solid solutions (x = 0.05, 0.15, 0.25, 0.35) were synthesized by carbothermal reduction and then were used as hard phases to prepare (Ti,W)C-Ni 3 Al cermets by vacuum sintering. (Ti,W)C-Ni 3 Al cermets showed weak core-rim structure carbide particles embedded in Ni 3 Al binder. As W content in (Ti,W)C increased, core-rim structure of carbide particles got weaker and the contrast of particles lowered down in SEM-BSE morphologies. Furthermore, the densification of cermets was promoted with W content in solid solution increasing, meanwhile TRS and toughness of cermets were improved obviously. In this paper, the wettability of molten metal on different group transition metal carbides was discussed in detail based on valence-electron configurations (VECs) of carbides. [ABSTRACT FROM AUTHOR]

The microstructure and mechanical properties of SLM and EBM Ti–6Al–4V samples have been compared. The effect of part size and orientation on the defects, microstructure and their contribution to the tensile and fatigue properties were elucidated. As-fabricated SLM and EBM samples mainly consisted of α′ and α + β phases, respectively. Pores were the main defects in SLM and EBM samples, and closely related to scanning strategies and energy input. The porosity of SLM samples was higher compared to EBM samples. The part size had an obvious influence on the microstructure and mechanical properties of EBM samples but less so for SLM samples. Both SLM and EBM samples possessed higher strength and better ductility in the vertical orientation than those in the horizontal orientation. The tensile strength of SLM samples was significantly greater than that of EBM samples whereas the ductility was much lower. Due to the pores contained in samples, fatigue strength of both EBM and SLM samples was lower than those of cast and annealed alloys. However, hot isostatic pressing (HIP) significantly increased the fatigue limits of both SLM and EBM samples to above 550 MPa by closing of the pores. [ABSTRACT FROM AUTHOR]

TiC–9.0TiN–19.5WC–0.5Cr 3 C 2 –0.3C–38.0(Ni– x Cr) ( x = 0, 10, 20 and 30 wt.%) cermets were prepared, to investigate microstructure and mechanical properties of Mo-free Ti(C,N)-based cermets with Ni– x Cr binders. 20–30 wt.% Cr in binders led to the obvious increase of the dissolution rate of WC, which was mainly attributed to the decease of the solid/liquid transition temperature of Ni-based binder phase. In the final microstructure, Ti(C,N) grains exhibited two kinds of the core/rim structure: one consisted of black core, white inner rim and grey outer rim, and the other consisted of white core and grey rim. Ti(C,N) grains with black core were on the whole larger in size, independently of Cr content in binders, and their grey outer rim increased in thickness with the increase of Cr content in binders. More often than not, white inner rims were thin and incomplete in shape, and there were fine white speckles in black cores, when Cr content in binders reached 20–30 wt.%. Lattice parameter of Ni-based binder phase increased with the increase of Cr content in binders, which was attributed to that the total amount of such alloying elements as Ti, W and Cr in this phase increased with the increase of Cr content in binders, and however, it increased slightly when Cr content in binders was in the range of 10–20 wt.%. Transverse rupture strength reached a peak value when Cr content in binders was 20 wt.%, and hardness increased with the increase of Cr content in binders. [ABSTRACT FROM AUTHOR]

Abstract The present work investigated magnetic and mechanical properties of TiC– x TiN–15MC– y Ni (wt.%, MC = Mo 2 C, WC, x = 0, 3, 6, 9, 12, 15, and y = 20, 40) cermets. Room-temperature (RT) saturation magnetization M s of Mo 2 C-containing and WC-containing cermets decreased with increasing x , and that of Mo 2 C-containing cermets was lower at the same x and y. Ferromagnetism disappeared at RT for Mo 2 C-containing cermets regardless of x and y and for WC-containing cermets at x = 15 for y = 20 and x ≥ 12 for y = 40, mainly due to high total content of non-magnetic Mo (or W) and Ti in binder phase. At x = 15, Curie temperature T c of Mo 2 C-containing cermets decreased to about 97 K for y = 20 and 16 K for y = 40. For Mo 2 C-containing cermets, transverse rupture strength (TRS) and hardness reached the maximum at x = 6 for y = 20, and they increased with increasing x for y = 40. For WC-containing cermets, TRS reached the maximum at x = 6 whereas hardness decreased slowly with increasing x for y = 20, and TRS and hardness reached the maximum at x = 12 and 6 for y = 40, respectively. TRS and hardness of Mo 2 C-containing cermets were higher than those of WC-containing cermets at the same x and y , except x = 0, 15 for y = 20, mainly due to stronger ceramic grain refinement strengthening effect and stronger substitutional solid-solution strengthening effect of binder phase. Highlights • RT M s of cermets decreased with increasing TiN content, regardless of MC. • Ferromagnetism of cermets disappeared at RT for MC = Mo 2 C, regardless of x and y. • Ferromagnetism of cermets disappeared at RT for MC = WC at x = 15 for y = 20, 40. • For MC = Mo 2 C, T c of cermets decreased to ∼97 K for y = 20 and ∼16 K for y = 40. • TRS and hardness of cermets were generally higher for MC = Mo 2 C than for MC = WC. [ABSTRACT FROM AUTHOR]

Microstructure and shear strength of Ti(C,N)-based cermet/Cu 30Ag 3Ti filler metal/W9Mo3Cr4V steel joints were investigated after brazing in vacuum at 870, 910, and 950 °C for 20 min, and 910 °C for 10, 20, 30 and 40 min. The reaction layer of Cu Ni Ti solid solution between cermet and filler metal was difficult to form during brazing at 870 °C, leading to very low shear strength of joints. During brazing at 910 °C, Cu Ni Ti solid solution was formed between cermet and filler metal, and it became thick with the increase of holding time. Shear strength of joints reached a peak value for 30 min, due to the appropriate thickness of Cu Ni Ti solid solution. During brazing at 950 °C, Cu Ni Ti solid solution was formed and then grew on the whole along with Ag-based solid solution in filler metal, but was not formed between cermet and filler metal, thus deteriorating shear strength of joints. [ABSTRACT FROM AUTHOR]

The optimized sintering conditions for a 3.5 wt% magnesia partially stabilized zirconia (Mg-PSZ) refractory were proposed in our recent research. The influence of the sintering temperature on the development of phase composition, microstructure, densification, thermal expansion and mechanical strength was studied in detail by X-ray diffraction (XRD), scanning electron microscope (SEM), He-pycnometer, high temperature dilatometry and three-point bending test. The samples sintered at 1670 °C had the highest bend strength, the maximum densification, the lowest thermal expansion coefficient (CTE), a homogeneous microstructure and a linear change in thermal expansion. [ABSTRACT FROM AUTHOR]

The effect of WC content on microstructure and mechanical properties of the TiC–Ni 3 Al system cermets was investigated. Ni 3 Al-bonded cermets showed a core–rim structure with carbide particle coupled with rim embedded in Ni 3 Al binder. With WC content increasing, TiC grains were refined and the white rim became complete and got thicker gradually. Interface between core and rim showed a completely coherent relationship. The rim enriched in W constituted an ideal coherence between hard phase and Ni 3 Al binder phase. With WC content increasing, the densification of cermets was enhanced, and hardness and TRS were increased firstly and then reduced, reaching peak values 90.9 HRA (HV 30 15 GPa) and 1629 MPa, respectively in cermet N5 (25 wt% WC). Similarly, fracture toughness got a peak value (11.6 MPa m 1/2 ), at the composition with 20 wt% WC. [ABSTRACT FROM AUTHOR]

Abstract: An easy method is described for fabricating carbon sheets with nanostructures using sucrose as a carbon precursor and a layered superabsorbent polymer (LSAP) as a structure-directing agent. The method is based on the interaction of the three-dimensional polymer networks of the LSAP with a sucrose solution in the hydrogel cells. The synthesis scheme consists of: (a) preparation of the LSAP, (b) preparation of layered hydrogels by immersing the LSAP in the sucrose solution for 2days, (c) carbonization of the layered hydrogels containing the sucrose solution. The synthesized carbon sheets show different microstructures including petal-like, regular and interleaved types, which can be controlled by simply adjusting the initial concentration of the sucrose solution in the hydrogel cells. Moreover, a formation mechanism for the carbon sheets is proposed. [ABSTRACT FROM AUTHOR]