| The TiZrNb alloy system for the replacement of artifical bone,joints and teeth is rapidly becoming more important. In this paper, element tin was added into the TiZrNb alloy system in order to change the microstructure and to improve the mechanical properties. The high purity of Ti(99.9%),Zr(99.99%),Nb(99.99%),Sn(99.99%) was selected in this experiment and then they were melted together as the system of Ti-17Zr-18Nb-xSn(x = 0,1,2,3,4,5) . Respectively, the test of microstucture, X-ray diffraction(XRD) and microhardness applied to alloys which casted, homogenized and solution treated. Standar tensile test,constraction test,transmission electron microscope(TEM)test and scanning electron microscope(SEM) test of tensile fracture were applied to solution treated alloys. The results showed that the alloy system metastableβtype titanium alloys. Tin can promote the formation ofα// phase during rapid cooling rate, and it tend to solute inβphase together withβstabilizer element Nb. The addition of tin strengthed the alloys by solution, while it also promoted the precipitation of softenedα// phase . Due to this two opposite effects of element tin, the hardness variation of solution treated alloys was similar to that of casted alloys. The solution of tin was dominant in homogenized alloys so the relatively smooth variation of hardness values was observed. Elastic modulus of the solution treated alloy system varied between 20 and 30GPa, and they were fit for artifical bone, but plasticity should been promoted. |
PDF Full Text Request