预变形退火对钛基非晶复合材料力学性能的影响

Effects of Pre-Deformation and Annealing on Mechanical Properties of Ti-Based Amorphous Alloys

摘要:

采用磁悬浮熔炼-水冷铜模吸铸法制备出Ti₄₀Ni₄₀Cu₂₀非晶基复合材料板状试样,通过压力试验机对试样进行不同程度的预压缩,然后在150℃、30min下退火,研究了预变形退火工艺对合金微观组织和力学性能的影响。结果表明：奥氏体相在外力作用下发生马氏体相变,形变诱导相变加之退火释放残余热应力从而对非晶基体起到增强增韧的作用。随着预变形程度的增加,马氏体相和奥氏体相均增加,而马氏体相增加的更快,复合材料的屈服强度提高,塑性减小, 塑形阶段预变形能够实现屈服强度可控；

Abstract:

Ti₄₀Ni₄₀Cu₂₀ amorphous matrix composite plate specimens were fabricated in the levitation suspend melting - water cooled Cu mold process. The specimens were by pre-compressed at different degrees with a pressure testing machine and then annealed at 150 ℃ for approx. 30 min. And the effects of the predeformation and annealing processes of the microstructure and mechanical properties of the Ti₄₀Ni₄₀Cu₂₀ alloy system were studied. The results show that the austenite phase into the martensitic phase transformation under external force occurred then. The phase transition induced by the deformation coupled with the annealing release of residual thermal stress plays a role in enhancing both strength and toughness of the amorphous matrix composite. Both martensite phases and austenite phases are increased with the increase in the degrees of pre-deformation, but martensite phases are increased faster. Thus the yield strength of the composite increased, while the ductility reduced .Therefore the controllable yield strength in the pre-compression stage for shaping can be realized.