Biomimetic apatite deposition behaviors and mechanical performance for as-rolled and annealed Ni-Ti plates were investigated . A good biomimetic apatite formation and excellent mechanical performance of Ni-Ti suggests that Ni-Ti can be an excellent candidate material as orthopedic implants.
Biomimetic apatite deposition behaviors on Zr-1Nb and Ti-6Al-4V plate with various surface conditions were examined. Both alloys were polished with abrasive papers to have different roughness and some of them were treated in NaOH before exposition in simulated body fluid. NaOH treatment was found to enhance the deposition rate of apatite on Ti-6Al-4V significantly. On the other hand, the deposition rate of Zr-1Nb was not influenced by NaOH treatment. Without NaOH treatment, the polished Zr-1Nb with abrasive paper was found to induce more apatite nucleation than the polished Zr-6Al-4V.
Micro-porous nickel (Ni) with an open cell structure was fabricated by powder metallurgy. The pore size of the micro-porous Ni approximated and . For comparison, porous Ni with a macro-porous structure were also prepared by both powder metallurgy (pore size ) and the traditional chemical vapour deposition method (pore size ). The mechanical properties of the micro-and macro-porous Ni samples were evaluated using compressive tests. Results indicate that the micro-porous Ni samples exhibited significantly enhanced mechanical properties, compared to those of the macro-porous Ni samples.
Ti-Zr-Ni coatings deposited by low vacuum plasma spray technique consisted of nanometer-sized 1/1 cubic approximant and TiZrNi Laves phases as well as a low volume fraction of phase. The shift of composition during deposition of the quasicrystalline powders and the presence of phases are believed to be responsible for the reduced corrosion performances evaluated by means of electrochemical tests in a Hanks' Balance Salt Solution at .
In a multi-action tooling system, which is usually used for the powder compaction process to fabricate the complex multilevel parts, crack formation is crucially detrimental and should be avoided. Among various process factors, tool shape is an important factor to prevent the crack formation during powder compaction process. In this work, the effects of different tool shapes were investigated through the experimental oberservation of pore distribution in real products and the finite element analysis of residual stresses. The results were interpreted based on non-uniform powder density in the compacted parts.