摘要
利用已有文献,结合修正的混合物模型和等功定律得到了Ti-6Al-4V钛合金中α相和β相在高温条件下的应力-应变关系,研究了合金在高温变形时两相的加工硬化率、应力-应变分配系数以及宏观应力和应变贡献率的变化规律。结果表明:β相和α相分别在宏观应变约为0.07和0.14时出现应变软化现象,且α相和Ti-6Al-4V钛合金在同一时刻开始出现应变软化现象,可见α相的应变软化行为在合金变形中发挥着重要作用;随变形的进行,两相应力-应变分配系数的绝对值逐渐降低,最终趋于稳定,表明两相变形的协调性得到改善;在变形达到稳定时,α相对宏观应力的贡献率比其体积分数大,而对宏观应变的贡献率比其体积分数小。
According to data in relevant literatures,the high temperature stress-strain relationship of α and β phase in Ti-6Al-4V titanium alloy was obtained by using the modified mixture model and law of equal work increment. The strain hardening rate,stress-strain partitioning coefficient,contribution rate to macro stress and strain of the constituent phases during high temperature deformation of Ti-6Al-4V titanium alloy were studied. The results show that the strain softening phenomenon of β and α phase is observed when the macro strain are0. 07 and 0. 14,respectively,and the strain softening phenomenon of Ti-6Al-4V titanium alloy and α phase appear at the same time which indicates that the strain softening behavior of α phase plays an important role in the deformation of Ti-6Al-4V titanium alloy. The absolute value of stress-strain partitioning coefficient decreases with the increasing strain and finally reaches to a stable state showing that the incoordinate deformation problem is improved observably. When the deformation of Ti-6Al-4V titanium alloy is stable,the contribution rate to macro stress of α phase is larger than its volume fraction,while the contribution rate to macro strain is smaller than its volume fraction.
作者
陈国兴
彭艳
CHEN Guo-xing PENG Yan(National Engineering Research Center for Equipment and Technology of Cold Strip Rolling, Yanshan University, Qinhuangdao ~, China State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2017年第5期107-112,共6页
Journal of Plasticity Engineering
基金
国家重点研发计划资助项目(2017YFB0306402
2017YFB0304103)
河北省高层次人才科学研究项目(5040040)
关键词
双相钛合金
应力-应变分配
贡献率
加工硬化率
dual-phase titanium alloy
stress-strain partitioning
contribution rate
strain hardening rate
