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In order to have a stronger bond with the surrounding bone, the bone prosthesis needs to have interconnecting pores for bone cells to grow and more importantly to avoid stress shielding. At the same time, human bones have different composition and structure of bone tissue in different parts of the body due to different physical factors of the person, so the elastic modulus of the bones that need to be supported and replaced are not the same. And additive manufacturing has the advantages of rapid, efficient and precise manufacturing of complex shapes and high-quality three-dimensional structures, which can manufacture porous scaffold bone prosthesis, and achieve more accurate mechanical property requirements by controlling the design parameters. To study the effect of design strut length and design strut cross-section diameter size on the elastic modulus of tetrahedral titanium alloy scaffold unit, and with the help of UG NX, several digital models of porous titanium alloy scaffolds were constructed with the strut length and the strut cross-section diameter size as the parameters of variation, and then the elastic modulus of each porous titanium alloy scaffold was measured by ANSYS Workbench 2022, and the elasticity modulus of each porous titanium alloy scaffold was further derived from the relationship between the strut length and strut cross-section diameter size and the porous titanium alloy scaffold. Then the elastic modulus of each porous titanium alloy bracket was measured by ANSYS Workbench 2022, and the mathematical model between the strut length, strut cross-section size and elastic modulus of the porous titanium alloy bracket was further derived. Then, ANSYS Workbench 2022 was used to measure the elastic modulus of each porous titanium alloy bracket and further derive the mathematical model between strut length, strut cross-section diameter size and elastic modulus of the porous titanium alloy bracket, with the help of which the elastic modulus of the porous titanium alloy bracket with specific diameters and strut lengths was finally deduced to validate the correctness of the above predicted mathematical model, and to make reasonable explanations and corrections for the deviations. explanation and correction of deviations. As a result, the rapid prototyping technology can be used to design the required porous titanium alloy bracket in a more detailed way. [ABSTRACT FROM AUTHOR]

To improve the wear resistance of the titanium alloy, the tungsten inert gas cladding was used in this study. The Stellite6-CeO2-MnSi-B4C composite coatings were fabricated on the Ti–6Al–4V (TC4) alloy by the preset-powder cladding process. The scanning electron microscope analysis of the composite coatings showed the effect of the different compositions on the microstructure. The crack propagations could be retarded to some extent due to an action of B4C. The high-resolution transmission electron microscope revealed the formation of the amorphous phases and the nanocrystals. The formation of amorphous phases could be induced by the lattice distortions. The results of sliding wear tests on the samples showed that the wear resistance of TC4 could be improved due to the synergy effects of the fine grain/ dispersion/ solid solution strengthening. [ABSTRACT FROM AUTHOR]

In this paper, the high-temperature oxidation resistant coating on the TA15 titanium alloy by laser cladding (LC) of the KF110-B4C-Ag mixed powders was analyzed in detail. The scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDS) images indicated that a good metallurgy bond between the fabricated coating/TA15 was formed; also the fine/compact microstructure was produced after a cladding process. The oxidation mass gain of TA15 was higher than that of the coating after LC process, which were 3.72 and 0.91 mg ⋅ cm − 2 , respectively, at 60 h, greatly enhancing the high temperature oxidation resistance. [ABSTRACT FROM AUTHOR]

• Multi-phase reinforced composites were fabricated by a LA process. • Large difference in atomic radius of such composites increased free energy. • Nanowall of GOSs and CNTs' tube could interwove together in some locations. • Partial nanocrystals led the error distributions of atoms to be formed. • UPs should diffuse into every location of a laser-pool extreme quickly. Laser alloying (LA) of the Nimonic93-Zn-SiB 2 -CeO 2 mixed powders formed a first layer by the coaxial powder feeding on a TA1 titanium alloy substrate; then the mixture powders of FeCoCrAlCu-TiC was alloyed on this formed first layer also by the coaxial powder feeding to produce the high entropy alloys (HEAs) base layer, forming the composites. The nanocrystals and the graphene oxide sheets (Graphene oxide sheets, GOSs)/CNTs reinforced layer were formed on an second layer, also by mean of LA of FeCoCrAlCu-TiC-(GOSs/CNTs). Portions of the produced ultrafine particles (UPs) were able to disrupt the balanced state of the atoms, enhancing the free energy of the crystal boundaries of such composites; UPs should diffuse into every locations of a laser-pool (LP) with an extreme high temperature as soon as possible. Wear performance of such composites was significantly higher than that of TA1 under an action of multi-phase. Identification of synthetic UPs in such fabricated composites, more importantly an UPs effect, contributes theoretical/experimental basis to upgrade quality of the laser fabricated materials with multi-phase. [ABSTRACT FROM AUTHOR]

The composites were obtained by the argon-arc cladding (AAC) of the Deloro22-Si3N4-Fe pre-placed powders on a TA1 titanium alloy substrate, which improved the wear resistance of the substrate. Such composites were investigated by means of the scanning electron microscope (SEM), the microscope and the high resolution transmission electron microscope (HRTEM). The results indicated that the amorphous phases were produced in such AAC composites, increasing the wear resistance. With addition of Y2O3, lots of the micro/nanoscale particles were formed, which further improved the wear resistance of such AAC composites. [ABSTRACT FROM AUTHOR]

The nanoscale quasicrystals (NQs), amorphous and ultrafine nanocrystals (UNs) modified hard composites are produced by laser cladding (LC) of the Ni60A-TiC-NbC-Sb mixed powders on the additive manufacturing (AM) TA1 titanium alloy. The LC technique is favorable to formations of icosahedral quasicrystals (I-phase) with five-fold symmetry due to its rapid cooling and solidification characteristics. The formation mechanism of this I-phase is explained here. Under the actions of NQs, amorphous and UNs, such LC composites exhibited an extremely high micro-hardness. UNs may also intertwin with amorphous, forming yarn-shape materials. This research provides essential theoretical basis to improve the quality of laser-treated composites. [ABSTRACT FROM AUTHOR]

Ultrafine nanocrystals (UNs) modified high-entropy alloy composites (HEACs) were fabricated by laser-melted deposition (LMD) of the yttria partially stabilized ZrO 2 (YPSZ) and the FeCoCrAlCu mixed powders on the aviation turbine blade made of the additive manufacturing (AM) TC17 titanium alloy. Such HEACs exhibited the finer microstructure free of micro-crack under an action of YPSZ, also relative stable atomic group of UNs owned the short-range order was produced attached to such HEACs matrix. Formation mechanisms of the AlCu 2 Zr UNs, amorphous and the nanoscale icosahedral quasicrystals (I-phase) with five-fold symmetry in HEACs were explored extensively by mean of the high resolution transmission electron microscope (HRTEM); also, under the actions of these various phases, such laser-induction HEACs exhibited the better wear performance than that of the FeCoCrAlCu LMD high-entropy alloy. With SiB 2 addition, lots of the one-dimensional nanostructure materials (nanorods) were produced, retained UNs can be easily reunited due to a surface effect, retarding growth of nanorods in a certain extent. This research may provide the essential theoretical and experimental basis to improve the quality of the laser 3D print composites. [ABSTRACT FROM AUTHOR]

The CoCrNi medium entropy alloy base coating (MEABC) was fabricated on the TC4 titanium alloy by the laser cladding (LC) technology, the effects of the ultrasonic vibration (UV) on the microstructures and the corrosion resistance of the coatings were studied. The MEABC was consisted primarily of BCC and (Ni,Co)Ti 2 , Cu could be precipitated at the grain boundary, producing the AlCu 2 Ti nanocrystals. The micro-forming quality of the coating was enhanced due to the UV effect. The temperature gradient/heat flux density of the UV assisted laser induced pool (LIP) were varied under an action of the high frequency vibration, refining the microstructure. The corrosion resistance and micro-hardness of the coating were enhanced due to the UV effects and the slow diffusion effect of the medium entropy alloy system, producing the multi-phase, such as the amorphous phases (APs) and the nanocrystalline phases (NPs), etc. This study provides the theoretical/experimental basis for the multi principal component coating by UV assisted LC process. • The medium entropy alloy base coatings with BCC and (Ni,Co)Ti 2 were fabricated. • The UV effect broke the precipitating dendrites, retarding the grain growth. • NPs/APs were formed due to the rapid cooling of LIP, forming multi-phase. • Atomic diffusion was promoted by UV, forming LAGBs to enhance corrosion resistance. [ABSTRACT FROM AUTHOR]

TiAg nanoscale particles (NP) and unmelted carbon nanotubes (CNTs) were observed in Ti-Al-Ag-CNTs-Y2O3laser alloying composite coating on TA7 titanium alloy, such coating greatly improved wear resistance of substrate surface. This coating was researched by means of X-ray diffraction, scanning electron microscope, and high-resolution transmission electron microscope. Such coating mainly consists of Ti-Al, TiAg, TiC, and amorphous phases. CNTs were covered by lots of NP. Being hindered by NP, CNTs were not free to grow. Nucleation and growth of amorphous phases were retarded by nanocrystals in a certain extent during the crystallization of amorphous. [ABSTRACT FROM PUBLISHER]

Abstract: An amorphous-nanocrystal reinforced composite coating was fabricated on Ti–6Al–4V titanium alloy by laser cladding (LC) of the Al3Ti–TiB2–(Ni-coated WC)–Al2O3–Y2O3 mixed powders. Test results indicate that the lots of the nanoscale particles (NP), nanorods and amorphous phases were produced in such coating. Amorphous/nanocrystalline interface owns a high bonding energy, which may retard the growth of nanocrystals in a certain extent. With Ce–Al–Ni amorphous addition, amorphous surrounded nanopolycrystals (ASNPs) were produced after the LC process. Although coarser microstructure was obtained with productions of ASNPs, the Ce–Al–Ni addition played an important amorphization effect on such LC coating, which was beneficial in increasing wear resistance of the LC coating. [Copyright &y& Elsevier]

Laser cladding of the A3Ti + TiC preplaced powders on the Ti-6Al-4V alloy can form the Ti3Al/TiC ceramic layer, which improved the wear resistance of the substrate. In this study, the influence of 7 wt% yttria partially stabilized zirconia ( YPSZ) on the surface performance of the Ti3Al/TiC ceramic layer was researched, and the Al3Ti + TiC/ YPSZ laser-cladded coating has been researched by means of X-ray diffraction, scanning electron microscope, and energy dispersive spectrometer. It was found that laser cladding of YPSZ can control the cracks in the Ti3Al/TiC ceramic layer. Furthermore, due to the action of YPSZ, stratification was observed in this ceramic layer. The upper layer in this coating consisted of Al2O3, Ti3Al, t- ZrO2, TiC, TiO2 and ZrSiO4, and Ti3Al/Al2O3 were the matrix of this region. This upper layer exhibited an excellent wear resistance due to its phase constituent. During the cladding process, YPSZ had a very marked trend to float on the surface of the coating. Therefore, the upper layer showed better wear resistance than that of the bottom layer due to the action of the high YPSZ content. [ABSTRACT FROM AUTHOR]

Laser cladding of the Fe3Al + B4C/TiN + Al2O3 pre-placed powders on the Ti-6Al-4V alloy can form the Ti3Al/Fe3Al + TiN/TiB2 composite coating, which improved the wear resistance of the Ti-6Al-4V alloy surface. In this study, the Ti3Al/Fe3Al + TiN/TiB2 composite coating has been researched by means of X-ray diffraction and scanning electron microscope. It was found that during the laser cladding process, Al2O3 can react with TiB2, leading to the formations of Ti3Al and B. This principle can be used to improve the Fe3Al + B4C/TiN laser-cladded coating on the Ti-6Al-4V alloy. Furthermore, during the cladding process, C consumed the oxygen in Fe3Al + B4C /TiN + Al2O3 molten pool, which retarded the productions of the redundant metal oxides. [ABSTRACT FROM AUTHOR]

Abstract: Laser cladding of the Fe3Al+TiB2/Al2O3 pre-placed alloy powder on Ti–6Al–4V alloy can form the Ti3Al/Fe3Al+TiB2/Al2O3 ceramic layer, which can greatly increase wear resistance of titanium alloy. In this study, the Ti3Al/Fe3Al+TiB2/Al2O3 ceramic layer has been researched by means of electron probe, X-ray diffraction, scanning electron microscope and micro-analyzer. In cladding process, Al2O3 can react with TiB2 leading to formation of amount of Ti3Al and B. This principle can be used to improve the Fe3Al+TiB2 laser cladded coating, it was found that with addition of Al2O3, the microstructure performance and micro-hardness of the coating was obviously improved due to the action of the Al–Ti–B system and hard phases. [Copyright &y& Elsevier]

Abstract: Laser cladding of the Al+TiC alloy powder on Ti–6Al–4V alloy can form the Ti3Al/TiAl+TiC ceramic layer. In this study, TiC particle-dispersed Ti3Al/TiAl matrix ceramic layer on the Ti–6Al–4V alloy by laser cladding has been researched by means of X-ray diffraction, scanning electron microscope, electron probe micro-analyzer, energy dispersive spectrometer. The main difference from the earlier reports is that Ti3Al/TiAl has been chosen as the matrix of the composite coating. The wear resistance of the Al+30wt.% TiC and the Al+40wt.% TiC cladding layer was approximately 2 times greater than that of the Ti–6Al–4V substrate due to the reinforcement of the Ti3Al/TiAl+TiC hard phases. However, when the TiC mass percent was above 40wt.%, the thermal stress value was greater than the materials yield strength limit in the ceramic layer, the microcrack was present and its wear resistance decreased. [ABSTRACT FROM AUTHOR]

• The CNTs reinforced composites were obtained by laser cladding. • The ceramics/nanocrystalline/amorphous phases were fabricated by LC. • The growth of the grain was hindered by the multi-phase in a certain extent, favoring APs to be fabricated. • The coating's COF decreased significantly by the self-lubricating effect. Carbon nanotubes (CNTs) reinforced composites were deposited on the TA2 titanium alloy by mean of a laser cladding (LC) of the Al 3 Ti-Cu-SiC-CNTs mixed powders, showing that huge amounts of the reinforced nanocrystalline phases/amorphous phases (APs) were fabricated in this coating; large amounts of the point defects were produced in the precipitates under an action of extreme high-temperature of a laser puddle; the mutual diffusion between C/Si can be achieved due to the similar atomic radii of them, forming APs. COF of this LC coating was in a range of 0.443 ~ 0.472, which was significantly lower than that of TA2 (0.562 ~ 0.581); considering that COF of this coating decreased significantly under actions of the Ti-Si-C compounds/CNTs due to self-lubricating effect, the reinforced phases in coating were beneficial to decrease COF due to the dispersion strengthening effect. [ABSTRACT FROM AUTHOR]

• SNCs reinforced HEAs base composites were formed; • Growth of TiB 2 /TiB may be retarded by Sb, resulting in SNCs; • Lots of UPs were produced in atomic arrangements of APs/MGOSs; • Ultrafine nano structure of the reinforcing phase was retained. Ultrafine particles (UPs)/amorphous phases (APs) reinforced composites was deposited on the TA15 titanium alloy via a laser cladding (LC) of the Co-Al-B 4 C-CeO 2 mixed powders; a LC technique (the laser power 900 W, the scanning speed 2.5 mm/s) favored APs/UPs to be produced owing to the transient existence of the laser molten pool (laser pool), its COF was in a range of 0.390–0.425. Then, the monolayer graphene oxide sheets (MGOSs)/carbon nanotubes (CNTs) reinforced composites were formed on this LC fabricated coating by a mean of LC of Co-Al-B 4 C-CeO 2 -(MGOSs/CNTs). Noting that a laser beam irradiated on MGOSs/CNTs also the pre-melted powders, huge amounts of MGOSs/CNTs were melted but kept partial MGOSs/CNTs in the solid states; also lots of UPs were produced in the atomic arrangements of APs/MGOSs, considering that partial UPs could obtain large quantity of the energy from a laser beam, forming lattice distortions. Identification of the synthetic UPs and MGOSs/CNTs in such LC composites, more importantly an UPs' effect, contributes the theoretical/experimental basis to improve quality of the laser 3D print fabricated composites. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) reinforced high-entropy alloy composites (HEACs) were fabricated on a TA2 titanium alloy by mean of a laser melting deposition (LMD) of the FeCoCrAlCu-(nano-SiB 6)-(Ni/Ag-coated CNTs) mixed powders, noting that large quantities of the ultrafine nanocrystals (UNs) were formed, portion of them were able to obtain the enormous energy from laser beam, which were able to permeate into the original ordered atom arrangement due to the high diffusion rates and their ultrafine microstructure. In substance, partial UNs can destroy the balanced state of atoms, increasing significantly the free energy of the crystal boundaries. Such CNTs/UNs modified LMD composites showed the better corrosion/high-temperature oxidation resistance properties than those of the TA2 alloy. Identification of the synthetic UNs in such LMD HEACs, more importantly the UNs transition effect, contributes theoretical/experimental basis to upgrade the quality of the industrial light alloy. [ABSTRACT FROM AUTHOR]

• The Deloro22-Si 3 N 4 -B 4 C composites were obtained by an argon-arc clad. • The NPs and amorphous phases modified composites were fabricated by LSS. • Vacuum tempering improved plastic/toughness properties of such LR composites. • The twin crystals can be formed by exceeding of the potential barrier of the atoms. The hard composites were fabricated by an argon-arc clad (AAC) of the Deloro22-Si 3 N 4 -B 4 C mixed powders on the TA1 titanium alloy substrate, which exhibited a relative coarse compact microstructure; then this substrate surface was treated by a laser beam, the microstructure evolution and formation mechanism of such AAC composites under the actions of laser surface strengthening (LSS) technique also the vacuum tempering process will be explored. Research results indicated that twice heat treatments changed greatly growth directions of the crystals, resulting in a net-like microstructure; also large amount of the atoms could obtain sufficient energy to exceed a potential barrier due to the extreme high temperature of the laser produced molten pool (laser-pool), forming the twin crystals; the vacuum tempering was able to remove the accumulation of the residual stress to a certain degree, improving the plastic and toughness performance of such LSS composites. To have a quantitative understanding of the AAC/LSS technologies effects, this paper has provided the laser technological/related theoretical basis to modify the ACC composites on the titanium alloy. [ABSTRACT FROM AUTHOR]

Ultrafine nanocrystals (UNs) and amorphous phases reinforced composites were fabricated on the bearing substrate produced of the titanium alloy by mean of the laser cladding (LC) of Stellite-Ceramics mixed powders, which improved the wear resistance of the substrate surface. An aim of this study is to investigate the microstructural characterization, phases constitute and wear behavior of such laser clad composites (LCCs). Test results indicated that the grain size/orientation in the different areas maintained highly consistent in middle region of the StelliteSF 12-NB-Sb LCCs, also three distinctive regions with varies equiaxed crystals in sizes can be distinguished, which showed a strong (101) orientation; the various types of phases were obtained for the bottom-composites due to the dilution effect and the extreme rapid cooling rate of the bottom-pool; the amorphous phases could not be free to grow up during crystallization process due to suppressions of UNs, resulting in the nanosize microstructure. To have a quantitative understanding of strengthening effects, this paper has provided laser-induced related theoretical basis to fabricate the ceramics reinforced composites on the light industrial part. [ABSTRACT FROM AUTHOR]