冷轧时效对新型Ti-Nb-Zr合金组织和性能的影响

利用X射线衍射仪(XRD)、光学显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)和拉伸测试等手段,研究形变热处理对新型 β(Ti-25Nb-25Zr)钛合金组织演变和力学性能的影响.结果表明:由于合金具有较高的β稳定性,冷轧过程没有应力诱发α″相的形成,合金的变形机制以位错滑移为主.随着冷轧变形量的增加,加工硬化...

Effect of cold rolling on microstructure and properties of Ti-Nb-Zr alloy by aging treatment

The effects of thermo-mechanical treatment on microstructure and mechanical properties of Ti-25Nb-25Zr alloy were investigated by X-ray diffraction(XRD),optical microscopy(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and tension tests.The results show that the alloy exhibits excellent phase stability that no stress-inducedα″phase transition occurs during cold rolling and the plastic deformation mechanisms are related to dislocation slipping.With the increase of the cold deformation,the hardness and elastic modulus decrease gradually.It’s found that the phase composition of aging products for the solution treated and the cold-rolled alloys areβ+ωandβ+αphases at 300℃for 2 h.The cold deformation produces much more dislocation defects and grain boundaries inhibits the nucleation of theωphase,whileαphase tends to nucleate at the dislocations and grain boundaries to promote the precipitation ofαphase.Compared with solution and aging,the aging treatment after cold deformation has high strength and ideal elastic modulus can satisfy the requirements for dental implant.