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powder metallurgy with space holder for porous titanium implants:A review

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Journal of Materials Science & Technology 2021年第17期76卷 129-149页

作者： Alejandra Rodriguez-Contreras Miquel Punset JoséA.Calero Francisco Javier Gil Elisa Ruperez JoséMaría Manero Biomaterials Biomechanics and Tissue Engineering Group(BBT)Department of Materials Science and EngineeringUniversitat Politecnica de Catalunya(UPC)Av.Edurad Maristany 1608019BarcelonaSpain Barcelona Research Centre in Multiscale Science and Engineering Technical University of Catalonia(UPC)Av.Eduard Maristany 10-1408019BarcelonaSpain UPC Innovation and Technology Center(CIT-UPC).Technical University of Catalonia(UPC) C.Jordi Girona 3-108034Barcelona.Spain AMES GROUP SA.Carretera Nacional 340 Pol.Ind."Les Fallulles"08620Sant Vicenc dels HortsBarcelonaSpain Bioengineering Institute for Technology Universitat Intemacional de Catalunyac/Josep Trueta s/n08195BarcelonaSpain

One of the biggest challenges in the biocompatibility of implantable metals is the prevention of the stress shielding effect,which is related to the coupling of the bone-metal mechanical *** stress shielding phenomenon provokes bone resorption and the consequent adverse effects on prosthesis ***,it can be inhibited by adapting the stiffness of the implant *** the use of titanium(Ti)porous structures is a great alternative not only to inhibit this effect but also to improve the osteointegration of orthopedic and dental implants,a brief description of the techniques used for their manufacturing and a review of the current commercialized implants produced from porous Ti assemblies are compiled in this *** powder metallurgy(PM)with space holder(SH)is a powerful technology used to produce porous Ti structures,it is here discussed its potential for the fabrication of medical devices from the perspectives of both design and *** most important parameters of the technique such as the size and shape of the initial metallic particles,the SH and binder type of materials,the compaction pressure of the green form,and in the sintering stage,the temperature,atmosphere,and time are reviewed according to the bibliography ***,the importance of the porosity and its types together with the influence of the mentioned parameters in the final porosity and,consequently,in the ultimate mechanical properties of the structure are ***,a few examples of the PM-SH application for the manufacturing of orthopedic implants are presented.

关键词： powder metallurgy Space holder method Porous titanium structures Medical devices Stress shielding effect Porous materials permeability Interconnected porosity Porous bone substitute materials Open-cell titanium foams Sintering-dissolution technique

powder metallurgy processed metal-matrix friction materials for space applications

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Friction 2018年第2期6卷 219-229页

作者： Yelong XIAO Pingping YAO Kunyang FAN Haibin ZHOU Minwen DENG Zongxiang JIN State Key Laboratory of powder metallurgy Central South University Shanghai Key Laboratory of Spacecraft Mechanism

Owing to the increasing demand for tribological brakes for space applications, the development of novel materials and advanced technologies is necessary. This paper presents the design, characterization, and realization of powder metallurgy processed metal-matrix friction materials intended for the above-mentioned tribological brakes. Selecting appropriate ingredients, which provides an effective way to tailor the properties of the friction material, is evolving as a strategy to meet the design requirements. The tribological behaviors of the friction material are experimentally investigated under different conditions, and special attention is focused on the vacuum tribology. Examinations and analyses of the friction surface and subsurface corroborate the wear mechanism. In addition, the erosion resistances of the friction material are evaluated by exposure tests of ultraviolet irradiation and atomic oxygen. Finally, present and potential space applications of the friction material are also introduced based on experimental studies.

关键词： friction & wear material designs space application irradiation powder metallurgy

Advanced hermetic electronic packaging based on lightweight silicon/aluminum composite produced by powder metallurgy technique

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Rare Metals 2020年第11期39卷 1307-1313页

作者： Yan-Qiang Liu Jian-Zhong Fan Xin-Xiang Hao Shao-Hua Wei Jun-Hui Nie Zi-Li Ma Ming-Kun Liu Ya-Bao Wang National Engineering and Technology Research Center for Nonferrous Metals Composites General Research Institute for Nonferrous MetalsBeijing100088China

Silicon/aluminum(Si/Al)composite is a kind of lightweight electronic packaging material that received a lot of attention in the past 20 *** this paper,a series of Si/Al composites with lowered coefficient of thermal expansion(CTE)and high thermal conductivity were produced by powder metallurgy(PM).The Si/Al composites are fully dense and have fine Si particles uniquely distributed within pure Al *** 50%Si/Al composites were designed to have strength in the range of 185-290 MPa to meet different demands,while the other properties keep *** toughness of the composites is measured to be 9-10 MPa·m^(1/2).The composites were machined to 50%Si/Al housings and 27%Si/Al *** the hermeticities of housings before and after laser-beam-welding sealing are *** measured leak rate of composites and sealed housings is in magnitude order of 1×10^(-10)and 1×10^(-9)Pa·m^(3)·s^(-1),respectively,suggesting high *** good hermeticity is attributed to the full dense materials,good weldability,and extremely low weld *** present Si/Al composites are expected to be extensively used in highly hermetic electronic packages.

关键词： Si/Al composite Electronic packaging Strength Hermetic powder metallurgy

A homogenous microstructural Mg-based matrix model for orthopedic application with generating uniform and smooth corrosion product layer in Ringer’s solution:Study on biodegradable behavior of Mg-Zn alloys prepared by powder metallurgy as a case

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Journal of Magnesium and Alloys 2021年第1期9卷 225-240页

作者： Yang Yan Xin Chu Xier Luo Xuemei Xu Yu Zhang YiLong Dai Ding Li Liangjian Chen Tao Xiao Kun Yu School of Materials Science and Engineering Central South UniversityChangsha 410083China Department of Materials Science and Engineering Yantai Nanshan UniversityYantai 265713China The Second Xiangya Hospital Central South UniversityChangsha 410011China The Third Xiangya Hospital Central South UniversityChangsha 410011China

For high corrosion resistance and extensively modified biodegradable Mg-based alloys and composites for bone implants,a new Mgbased matrix model prepared by powder metallurgy is discussed and *** this research,Mg-5 wt.%Zn alloys were selected as a *** they were impacted by hot extrusion and aging treatments to construct microstructure with different *** selfforming corrosion product layer in Ringer’s solution,biodegradable behavior and corrosion mechanism were minutely investigated by in vitro degradation,electrochemical corrosion and *** results demonstrated the extruded Mg-5 wt.%Zn alloy aged for 96 h showed high corrosion resistance,good biocompatibility for L929 and excellent ability of maintaining sample integrity during the ***,the alloy showed fine-grain microstructure and uniform distributed hundred nano-sized second phases,which promoted the formation of the uniform and smooth corrosion product layer at the beginning of *** corrosion product layer was more stable in chloride containing aqueous solution and could be directly formed and repaired quickly,which effectively protected the matrix from further *** addition,an ideal model of Mg-based matrix for bone tissue engineering was tried to presume and propose by discussing the causal relationship between microstructure and bio-corrosion process.

关键词： Magnesium alloys powder metallurgy Second phase Corrosion product layer Biodegradable behavior Cytocompatibility

Effect of cold working and annealing on microstructure and properties of powder metallurgy high entropy alloy

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Science China(Technological Sciences) 2018年第2期61卷 197-203页

作者： LIU Bin XU LiYou LIU Yong WANG JingShi WANG JiaWen FANG QiHong State Key Lab of powder metallurgy Central South UniversityChangsha 410083China College of Mechanical and Vehicle Engineering Hunan UniversityChangsha 410082China

An equiatomic CoCrFeNiMn high entropy alloy （HEA） was produced by powder metallurgy method. Cold rolling followed by subsequent annealing was conducted to further optimize the microstructure and mechanical properties. The results show that the SPSed CoCrFeNiMn HEA has an equiaxed single fcc phase microstructrue. Cold rolling results in extensive dislocation pile-up and twinning within the grains. The 80% cold-rolled alloy shows very high yield strength of 1292 MPa, but a limited elongation of 3%. Subsequent annealing produces recrystallization and precipitation of fine a particles with particle size of 30-100 nm. The annealed alloy has a yield strength of 540 MPa, which is about two to three times of the cast CoCrFeNiMn HEA, while still maintains a high tensile ductility of 41%. The improvement of the tensile properties is caused by the grain boundary strengthening, solid solution strengthening, and precipitation strengthening.

关键词： powder metallurgy high entropy alloy annealing cold rolling mechanical properties

Al–TiO_2–Gr powder metallurgy hybrid composites with cold upset forging

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Rare Metals 2014年第6期33卷 686-696页

作者： M.Ravichandran A.Naveen Sait V.Anandakrishnan Department of Mechanical Engineering Chendhuran College of Engineering and Technology Department of Production Engineering National Institute of Technology

The cold upsetting studies were carried out for the aluminium metal matrix hybrid composites in the present study. Aluminium metal matrix hybrid composites were synthesised through powder metallurgy route from ball-milled powders to yield the following compositions：Al ＋ 2.5 wt% TiO2＋ 2 wt% Gr, Al ＋ 2.5 wt% TiO2＋ 4 wt% Gr, Al ＋ 5.0 wt% TiO2＋ 2 wt% Gr and Al ＋ 5.0 wt% TiO2＋ 4 wt% Gr. The compaction process was carried out using suitable punch and die in 40 k N hydraulic press, and sintering was done in an electric muffle furnace at the temperature of 590 °C for 3 h. The sintered preforms were subjected to incremental compressive loading of 10 k N until the cracks were found at the free surface. The true axial stress, true hoop stress, true hydrostatic stress and true effective stress were calculated for all the preforms, and all these stresses are correlated with the true axial strain. The stress ratio parameters（rz/reff, rh/reff, rz/rmand rh/rm） of the all preforms were correlated with true axial strain. The maximum true axial stress, true hoop stress, true effective stress and hydrostatic static stress are obtained for the composite containing5 wt% of TiO2 and 4 wt% of graphite and the minimum ones are obtained for composite containing 2.5 wt% of TiO2 and 2 wt% of graphite.

关键词： Metal matrix composites Cold upsetting powder metallurgy

Microstructure evolution and strengthening mechanism of high -performance powder metallurgy TA15 titanium alloy by hot rolling

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International Journal of Minerals,metallurgy and Materials 2024年第6期31卷 1426-1436页

作者： Ying Gao Ce Zhang Jiazhen Zhang Xin Lu Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsInstitute for Advanced Ma-terials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China National Engineering Research Center for Advanced Rolling Technology National Engineering Research Center for Flat Rolling EquipmentInstitute of Engin-eering TechnologyUniversity of Science and Technology BeijingBeijing 100083China

Hot deformation of sintered billets by powder metallurgy(PM)is an effective preparation technique for titanium alloys,which is more significant for high-alloying *** this study,Ti–6.5Al–2Zr–Mo–V(TA15)titanium alloy plates were prepared by cold press-ing sintering combined with high-temperature hot *** microstructure and mechanical properties under different process paramet-ers were *** microscope,electron backscatter diffraction,and others were applied to characterize the microstructure evolution and mechanical properties strengthening *** results showed that the chemical compositions were uniformly dif-fused without segregation during sintering,and the closing of the matrix craters was accelerated by increasing the sintering *** block was hot rolled at 1200℃ with an 80%reduction under only two passes without *** strength and elongation of the plate at 20–25℃ after solution and aging were 1247 MPa and 14.0%,respectively,which were increased by 24.5%and 40.0%,respect-ively,compared with the as-sintered alloy at 1300℃.The microstructure was significantly refined by continuous dynamic recrystalliza-tion,which was completed by the rotation and dislocation absorption of the substructure surrounded by low-angle grain *** hot rolling combined with heat treatment,the strength and plasticity of PM-TA15 were significantly improved,which resulted from the dense,uniform,and fine recrystallization structure and the synergistic effect of multiple slip systems.

关键词： elemental powder powder metallurgy titanium alloy hot rolling strength and plasticity

Microstructure and Lattice Parameters of AIN Particle-Reinforced Magnesium Matrix Composites Fabricated by powder metallurgy

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Acta Metallurgica Sinica(English Letters) 2015年第11期28卷 1354-1363页

作者： Jie Chen Chong-Gao Bao Yong Wang Jin-Ling Liu Challapalli Suryanarayana State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi'an Jiaotong University State Key Laboratory of Traction Power School of Mechanics and EngineeringSouthwest Jiaotong University Department of Mechanical and Aerospace Engineering University of Central Florida

Magnesium matrix composites reinforced with AlN particles were fabricated by the powder metallurgy technique. The evolution of lattice constants and solid solubility levels of Al in α-Mg and the microstructure of Mg-Al/AlN composites were investigated in the present study. The results showed that the solid solubility of Al in α-Mg reached a relatively high level by the P/M process with a long time of milling. X-ray diffraction showed that the peaks of Mg phase clearly shifted to higher angles. The lattice constants and cell volume decreased significantly compared with those of standard Mg due to a significant amount of Al incorporated into α-Mg in the form of substitutional solid solution. The degree of lattice deformation decreased at a low sintering temperature and increased at higher sintering temperatures due to the presence of AlN. Microstructural characterization of the composites revealed a necklace distribution of AlN particles in the Mg matrix. Heat treatment led to precipitation of Mg17Al12 from the supersaturated α-Mg solid solution. The pre- cipitate exhibited granular and lath-shaped morphologies in Mg matrix and ftocculent precipitation around AlN particles.

关键词： Metal matrix composite AIN particle Microstructure Lattice parameter powder metallurgy Solid solubility

Microstructures and grain refinement performance of Al-Ti-B-C grain refiner via powder metallurgy

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Rare Metals 2022年第7期41卷 2357-2362页

作者： Cong Xu Wen-Long Xiao Shi-Zhen Wen Yue-Jun Zhen Chao-Li Ma Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education School of Material Science and EngineeringBeihang UniversityBeijing 100191China Lizhong Group Baoding Lizhong Wheel Manufacturing Co.Ltd.Baoding 071000China

The Al-5Ti-0.5B-0.5C grain refiner was pre-pared by powder metallurgy(PM).Microstructures of the grain refiner and its grain refinement performance in commercially pure aluminum(Al)were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),and differential scanning calorimetry(DSC).It is found that the average grain size of commercially pure Al can be reduced from~15,000 to~180μm by the addition of Al-5Ti-0.5B-0.5C grain refiner prepared by PM,based on 0.01 wt%Ti *** grain refinement efficiency begins to decrease slightly when the grain refiner is kept in the melt for 60 *** grain refinement is attributed to high stability,proper size,and high density of Al3Ti,TiB2,and TiC particles.

关键词： Al–Ti–B–C powder metallurgy Microstructure Grain refinement