Li Fuping
,
Li Jinshan
,
Kou Hongchao
,
Zhou Lian
材料科学技术（英文）
doi:10.1016/j.jmst.2016.08.007
In this work, porous Ti6Al4V alloys with 30%-70% porosity for biomedical applications were fabricated by diffusion bonding of alloy meshes. Pore structure was characterized by Micro-CT and SEM. Compressive behavior in the out-of-plane direction and biocompatibility with cortical bone were studied. The results reveal that the fabricated porous Ti6Al4V alloys possess anisotropic structure with square pores in the in-plane direction and elongated pores in the out-of-plane direction. The average pore size of porous Ti6Al4V alloys with 30%-70% porosity is in the range of 240-360?μm. By tailoring diffusion bonding temperature, aspect ratio of alloy meshes and porosity, porous Ti6Al4V alloys with different compressive properties can be obtained, for instance, Young's modulus and yield stress in the ranges of 4-40?GPa and 70-500?MPa, respectively. Yield stress of porous Ti6Al4V alloys fabricated by diffusion bonding is close to that of alloys fabricated by rapid prototyping, but higher than that of fabricated by powder sintering and space-holder method. Diffusion bonding temperature has some effects on the yield stress of porous Ti6Al4V alloys, but has a minor effect on the Young's modulus. The relationship between compressive properties and relative density conforms well to the Gibson-Ashby model. The Young's modulus is linear with the aspect ratio, while the yield stress is linear with the square of aspect ratio of alloy meshes. Porous Ti6Al4V alloys with 60%-70% porosity have potential for cortical bone implant applications.
关键词:
Porous biomaterials
,
Titanium alloys
,
Diffusion bonding
,
Compressive behavior
,
Bioadaption
Guisheng ZOU
,
Jun YANG
,
Aaiping WU
,
Genghua HUANG
,
Deku ZHANG
,
Jialie REN
,
Qing WANG
材料科学技术（英文）
Ti foil and Ti/Ni/Ti multiple interlayers were selected for the bonding of tungsten to copper and CuCrZr alloy. The effects of processing conditions on the microstructures and shear strength of the joints were investigated. When Ti foil is used for bonding of tungsten to pure copper but not transformed into liquid solution during the holding time, the strength of the joints is relatively low because of the multiple compound layers with brittleness formed in the bonding zone. The strength of the joints increases significantly if the Ti foil is transformed into liquid solution and is mostly extruded out of the bonding zone. The same phenomena are found in the case when Ti/Ni/Ti multi-interlayers are used for bonding tungsten to CuCrZr alloy.
关键词:
Tungsten
,
null
,
null
,
null
Kaifeng ZHANG
,
Wenbo HAN
,
Wei WU
,
Guofeng WANG
,
Dezhong WU
材料科学技术（英文）
The research on numerical simulation for combinative process of SPF/DB is carried out in this paper. The contacting problem of sheets is analyzed by using the penalty method. In order to solve the contact problem of different parts of the sheet, a new algorithm for contacting judgment is proposed. According to the relation of the distance vector and the vector of contacting element area, and the condition of contact, it can be judged whether or not a node on the slave surface and the corresponding master surface are in the state of SPF/DB. The Mindlin shell element is employed to simulate SPF/DB process of an asymmetry double-cell cup of Ti-6Al-4V to examine the efficiency of the new algorithm using ARVIP-3D. The results of the numerical simulation are in good agreement with experimental results.
关键词:
Numerical simulation
,
null
,
null
,
null
Wenbo HAN
,
Kaifeng ZHANG
,
Guofeng WANG
,
Xiaojun ZHANG
材料科学技术（英文）
Superplastic forming and diffusion bonding (SPF/DB) is a well-established process for the manufacture of components almost exclusively from Ti-6Al-4V sheet material. The sandwich structure of Ti-6Al-4V alloy is investigated. The effects of the microstructure on the SPF/DB process were discussed. The microstructure at the interfaces and the distribution of thickness were researched.
关键词:
Superplastic forming
,
null
,
null
,
null
Wei GUO
,
Jitai NIU
,
Jinfan ZHAI
,
Changli WANG
,
Jie YU
,
Guangtao ZHOU
材料科学技术（英文）
Through the vacuum diffusion bonding for SiCp/ZL101 aluminum matrix composite, the influence of bonding parameters on the joint properties was reported, with the aim to obtain optimal bonding parameters. The microstructure of joints was analyzed by means of optical microscope and scanning electron microscope in order to study the relationship between the macro-properties of joints and the microstructures. It was found that diffusion bonding could be used for bonding aluminum matrix composites successfully. Meanwhile, the properties of the matrix and the joint were all affected by some defects such as the reinforcement aggregation in aluminum matrix composites made by stirring casting.
关键词:
Aluminum matrix composite
,
null
,
null
,
null
