Ti-4Al-5Mo-6Cr-5V-1Nb合金的热变形行为及组织演变研究  

Research on Thermal Deformation Behavior and Microstructure Evolution of Ti-4Al-5Mo-6Cr-5V-1Nb Alloy

作　　者：周琳 刘运玺 陈玮 付明杰[1] ZHOU Lin;LIU Yunxi;CHEN Wei;FU Mingjie(AVIC Manufacture Technology Institute,Beijing 100024,China;Key Laboratory of Power Beam Processing,Beijing 100024)

机构地区：[1]中国航空制造技术研究院,北京100024 [2]高能束流加工技术重点实验室,北京100024

出　　处：《热加工工艺》2022年第2期45-50,共6页Hot Working Technology

基　　金：装备预研领域基金项目(61409230409)。

摘　　要：采用Gleeble-3800动态模拟实验机,研究了亚稳β钛合金Ti-4Al-5Mo-6Cr-5V-1Nb在变形温度700~900℃、应变速率0.001~1s^(-1)、变形量10%~50%的热变形行为,分析了该合金在热变形过程中的组织性能演变规律。结果表明:随变形量的增加,合金的流动应力曲线变化不大,主变形区组织畸变程度增大,且变形晶的动态再结晶增加;随变形温度的增加,合金的峰值应力及稳态流变应力呈降低趋势,组织变形趋于均匀分布,动态再结晶程度亦增加,且因应力诱发相变导致组织在稍低于相变点的790℃完全转化为β相;随应变速率增加,合金的峰值应力及稳态流变应力增加,组织变形不均匀程度增加,动态再结晶程度降低。该合金为变形温度、应变速率敏感型材料,其温度敏感性随应变速率的增加而逐渐增强,应变速率敏感性随温度的增加而逐渐减弱。The thermal deformation behavior of metastable β titanium alloy Ti-4Al-5Mo-6Cr-5V-1Nb was investigated by using dynamic simulator Gleeble-3800 under the condition of deformation temperature from 700 ℃ to 900 ℃ and strain rates from 0.001 s^(-1) to 1 s^(-1) and strain from 10 % to 50 %. The microstructure evolution and properties of the alloy during thermal deformation process were analyzed. The results show that the flow stress curves of the alloy don’t change much with the increase of strain, the distortion of microstructure in main deformation zone and dynamic recrystallization of deformed crystals increase. With the increase of deformation temperature, the peak stress and steady-state flow stress of the alloy decrease, the microstructure deformation tends to distribute uniformly, and the degree of dynamic recrystallization also increases. Otherwise, due to stress-induced phase transformation, the structure transforms into β phase completely at 790 ℃,which is lower than the transformation temperature slightly. As the strain rate increases, the peak stress and steady-state flow stress increase, the microstructure distortion is more and more inhomogeneous, and the degree of dynamic recrystallization decreases. The alloy is a material sensitive to temperature and strain rate. Its temperature sensitivity increases gradually with the increase of strain rate, and the strain rate sensitivity decreases gradually with increasing temperature.

关 键 词：Ti-4Al-5Mo-6Cr-5V-1Nb合金 热变形行为 流变应力 组织演化 

分 类 号：TG146.2[一般工业技术—材料科学与工程]