Ti5Mo5V3Al-xCr系合金等温时效相变动力学

Isothermal Phase Transition Kinetics of Ti5Mo5V3Al-xCr Alloys

利用同步X射线衍射技术研究了Ti5Mo5V3Al-xCr(x=1.0,3.0,5.0,7.0和9.0)系列合金在550℃的α+β→β等温相变动力学。结果显示,Ti5Mo5V3Al-xCr系列合金等温相变为长程扩散控制型相变,相变过程可以用JMA方程进行宏观描述。等温时效过程中,1Cr合金的相变速率最快,且随Cr含量的增加,相变速率变慢。Cr含量随平衡态α相含量增加呈线性递减规律。Cr元素含量对合金相变点及平衡态相含量的影响是造成合金系等温相变动力学行为差异的主要原因。

In this experiment,theα+β→βisothermal phase transition kinetics of Ti5Mo5V3Al-x Cr(x=1.0,3.0,5.0,7.0 and 9.0)alloys at 550℃were studied by synchronous X-ray diffraction technique.The results showed that the isothermal phase transition of Ti5Mo5V3Al-x Cr alloys belonged to the transition of nucleation and growth,controlled by long range diffusion and could be described by JMA equation macroscopically.During the procedure of aging treatment at 550℃,the phase transformation rate of 1Cr alloy was relatively fast.With the increase of chromium content,the phase transition slowed down.The content of Cr was linearly decreasing with the content of the equilibrium phase.The influence of Cr element content on the phase transformation and equilibrium phase content was the main reason for the difference in the isothermal phase transformation behavior of the alloy system.