Ti3Zr2Sn3Mo25Nb钛合金表面细晶的表征方法

Characterization methods of fine grain on the surface of Ti3Zr2Sn3Mo25Nb titanium alloy

采用超声冲击的方法对Ti3Zr2Sn3Mo25Nb钛合金进行表面强化,采用扫描电镜、透射电镜、电子背散射衍射仪、X射线衍射仪等设备对其表面细晶进行表征。结果表明:超声冲击后,钛合金表面获得了深度约为35μm的强塑性变形层;钛合金表面可观察到明显纳米级的非晶团簇和密集的滑移线,细晶形成的主要原因为位错滑移,位错滑移的主方向为<111>;超声冲击后,材料的表面残余压应力约为250 MPa,晶格常数略有降低,β相的特征峰强度变大,α相的特征峰宽度变大。

The surface of Ti3Zr2Sn3Mo25Nb titanium alloy was strengthened by ultrasonic impact.The surface fine grains were characterized by scanning electron microscopy,transmission electron microscopy,electron backscatter diffraction and X-ray diffraction.The results show that a strong plastic deformation layer with a depth of about 35μm was obtained on the surface of titanium alloy after ultrasonic impact.Obvious nanoscale amorphous clusters and dense slip lines could be observed on the surface of titanium alloy.The main reason for the formation of fine grains was dislocation slip and the main direction of dislocation slip was<111>.After ultrasonic impact,the residual compressive stress on the surface of the material was about 250 MPa,the lattice constant decreased slightly,the characteristic peak intensity ofβphase increased and the characteristic peak width ofαphase increased.