搅拌摩擦加工TA5钛合金的显微组织和力学性能

对TA5钛合金进行搅拌摩擦加工(FSP),获得超细晶组织.为了研究搅拌摩擦加工过程中的温度分布和材料流动情况,使用欧拉-拉格朗日耦合(CEL)方法对加工过程进行热力耦合模拟.采用光学显微镜、扫描电镜、硬度和拉伸测试技术对合金的显微组织和力学性能进行表征.由于在加工过程中材料发生动态再结晶,因此,加工后的合金由细小等轴晶...

Microstructure and mechanical properties of friction stir processed TA5 alloy

Ultra-fine grained TA5 titanium alloy was fabricated by friction stir processing (FSP). Temperature distribution and material flow were simulated by the coupled Euler–Lagrange (CEL) method. The microstructure and mechanical properties of TA5 alloy were characterized by optical and scanning electron microscope, Vickers hardness, and tensile tests. The processed alloy was composed of ultra-fine grained and equiaxed grains due to dynamic recrystallization. The microstructure recrystallized through grain boundary rotation and dislocation accumulation. The grain size reached the minimum on the advancing side of the stir zone with the highest grain misorientation. Ultimate tensile strength was promoted to over 830 MPa after FSP at a rotating speed of 200 r/min, whereas elongation varied a little. The specimens all fractured on the retreating side of the stir zone and smaller dimples were depicted from the fracture morphologies of FSP specimens.