生物医用TC20钛合金高温变形行为及本构关系  

Hot Deformation Behavior and Constitutive Relationship of Biomedical TC20 Alloy

作　　者：刘延辉[1] 姚泽坤[1] 宁永权[1] 郭鸿镇[1] 

机构地区：[1]西北工业大学材料科学与工程学院,西安710072

出　　处：《材料工程》2014年第7期16-21,共6页Journal of Materials Engineering

基　　金：国家自然科学基金(51101119;51175431);中国博士后科学基金(2012T50818)

摘　　要：采用Gleeble-1500热模拟试验机对TC20合金进行等温热模拟压缩实验.分析该合金在变形温度为750900℃,应变速率为0.0011.0s-1条件下的变形行为及流变应力的变化规律.分析不同变形温度和变形速率下的热变形行为及其微观组织的演变规律,观察结果表明：流变应力和微观组织受变形温度和应变速率显著影响;流变应力随变形温度的升高和应变速率的降低而降低,流变应力在经历加工硬化的上升阶段后达到硬化和软化相平衡的稳定阶段.采用双曲正弦模型确定该合金的变形应力指数n和变形激活能Q分别为4.43和340.908kJ/mol,建立了相应的热变形本构方程为：ε=2.706x10^16[sinh（0.0091σ）]572exp[-340908/（RT）].The hot compression behavior of TC20 alloy was investigated by Gleeble-1500 simulation atthe deforming temperature range from 750℃ to 900℃ and the strain rate range from 0. 001s-1 to1.0s-1. The organizational structures and flow stress under the different temperature and strain ratewere analyzed. The results show that the flow stress and the microstructure are influenced strikinglyby both deforming temperature and strain rate;the flow stress decreases with increasing deformingtemperature and decreasing strain rate. After work hardening of the rising stage, the flow stresses a-chieve hardening and softening equilibrium stability stage. The stress exponential n and deformationactivation energy Q are obtained on the base of the hyperbolic sin constitutive equations, and they are4.43 and 340. 908kJ/mol, respectively. The constitutive equation of TC20 alloy is： ε=2.706x10^16[sinh（0.0091σ）]572exp[-340908/（RT）].

关 键 词：高温变形行为 钛合金 本构关系 热模拟试验机 热变形行为 变形温度 流变应力 医用 

分 类 号：TG146[一般工业技术—材料科学与工程]