Preparation Methods And Influencing Factors Of Structural Properties Of Porous Titanium

In this paper, the place holder packing method and gel casting method are prepared to porous titanium, by adjusting porosities of the porous titanium, mechanical properties of bone tissue match the performance of titanium implant materials and bone tissue to relieve stress shielding.The place holder packing method is prepared to porous titanium with titanium (Ti,10～40μm,5～20μm) by vacuum sintering of Ti powders (10～40μm) using ammonium bicarbonate (100～400μm) as the porogen. And to examine sintering temperature, holding time, heating time, the titanium powder content of the porous titanium micro-structure (porosity, opening porosity) and mechanical properties (maximum compressive strength, Young’s modulus) of impact. Sintering temperature selected as1000℃,1100℃,1200℃,1300℃. Holding time selected as1h,1.5h,2h,3h; Heating time selected as4.5h,5h,5.5h,6h; the content of titanium powder selected as45%,50%,55%,60%,65%. The optimum processing conditions were:heating time4.5h and sintering at1200℃for2h. The porous Ti prepared under these optimum conditions had a total porosities of63.5%, open porosities of64.9%, compressive strengths of150.7MPa, and Young’s modulus of2.91GPa. Macro-porous and micro-porous pore size range of100～400μm with10～40μm. Sintering temperature, holding time on the microstructure and mechanical properties of porous titanium greater impact, and sintering temperature is the main factors and holding time is the secondary factors, the heating time is less affected. How much of the content of titanium powder also has a significant effect on the microstructure and mechanical properties of porous titanium.Above all, Titanium hydride (100～400μm) to the study of titanium hydride and the impact on the microstructure and mechanical properties of porous titanium, titanium hydride addition amount of preferably5%,7.5%,10%,12.5%,15%,20%. Results showed that: when the titanium hydride10%(titanium powder and titanium hydride mass ratio of4:1), the the porous titanium microstructure and mechanical properties, porosity of69.5%, opening porosity of70.2%, maximum compressive strength of180.6MPa, elastic modulus3.12GPa, macro-porous and micro-porous pore size range of100～500μm with10～50μm. Adding a small amount of titanium hydride content of less than10%, help to improve the micro-structure of the porous titanium, mechanical properties and pore size range.Gel casting preparation of porous titanium, when anhydrous lithium chloride for4g, chitin0.56g, N-N dimethyl acetamide100ml slurry was prepared, the porous titanium is prepared, porosities of56.4%, opening porosities of69.7%, maximum compressive strength of204.5MPa, elastic modulus3.16GPa, macro-porous and micro-porous pore size range were100～200μm and10～20μm.Gel casting method, and the place holder packing method, the former is able to provide greater strength and modulus, but are too small compared to the number of pores and macro-pore size of the latter; the latter is able to get higher porosities and macro-pore size of but strength and modulus compared to the former are small. Thus, according to the specific experimental need to select the specific test method.