基于球化机理的TA15钛合金热变形统一本构模型  

Unified constitutive model of TA15 titanium alloy in hot deformation based on the globularization mechanism

作　　者：赵慧俊 王宝雨[1] 刘钢[2] 杨雷[1] 

机构地区：[1]北京科技大学机械工程学院,北京100083 [2]哈尔滨工业大学材料科学与工程学院,哈尔滨150001

出　　处：《北京科技大学学报》2014年第7期925-930,共6页Journal of University of Science and Technology Beijing

基　　金：现代交通金属材料与加工技术北京实验室资助项目;高等学校博士学科点专项科研基金资助项目(20120006110017)

摘　　要：应用晶界分离模型解释了片层α相的球化现象,阐述了TA15钛合金转变组织中次生片层α相的球化是其主要的流动软化机制.基于钛合金球化软化机理,建立了TA15钛合金的统一黏塑性本构模型.本构模型综合考虑了次生α相的球化、正则位错密度、等向硬化、塑性成形产生的温升、成形过程中的相变等物理变量.利用遗传算法确定了本构模型中的材料常数.本构模型能够较好地描述TA15钛合金热变形下的流动应力变化.Globularization of lamellar α phase was stated by the grain boundary separating model. It was elucidated that globularization of secondary （ lamellar） αphase in the transformed microstructure is the main flow softening mechanism of TA15 titanium alloy. A unified viscoplastic constitutive equation of TA15 titanium alloy was developed based on the globularization mechanism. Some physical variables including globularization of secondary （ lamellar） αphase, normalized dislocation density, isotropic hardening, plastic deformation induced temperature rise, and phase transformation during deformation were comprehensively considered in the constitutive model. Material constants in the constitutive model were determined and optimized by a genetic algorithm. The constitutive model can accurately predict the flow stress of TA15 titanium alloy in hot deformation.

关 键 词：钛合金 球化 本构模型 遗传算法 材料常数 

分 类 号：TG146.23[一般工业技术—材料科学与工程]