Constitutive equation and processing map for hot compressed as-cast Ti-43Al-4Nb-1.4W-0.6B alloy  

Ti-43Al-4Nb-1.4W-0.6B合金的本构方程以及加工图(英文)

作　　者：李建波[1] 刘咏[1] 王岩[2] 刘彬[1] 卢斌[1] 梁霄鹏[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083 [2]中南大学航空航天学院,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2013年第11期3383-3391,共9页中国有色金属学报（英文版）

基　　金：Project(2011CB605505)supported by the National Key Fundamental Research Development Project of China;Projects(51301204,51174233)supported by the National Natural Science Foundation of China;Project(2011JQ002)supported by the Fundamental Research Funds for the Central Universities of China

摘　　要：High temperature compressive deformation behaviors of as-cast Ti-43Al-4Nb-1.4W-0.6B alloy was investigated at temperatures ranging from 1323 K to 1473 K, and strain rates from 0.001 s-1 to 1 s-1. The results indicated that the true stress-true strain curves show a dynamic flow softening behavior. The flow curves after the friction and the temperature compensations were employed to develop constitutive equations. The effects of temperature and the strain rate on the deformation behavior were represented by Zener-Holloman exponential equation. The influence of strain was incorporated in the constitutive analysis by considering the effect of the strain on material constants by a five-order polynomial. A revised model was proposed to describe the relationships among the flow stress, strain rate and temperature and the predicted flow stress curves were in good agreement with experimental results. Appropriate deformation processing parameters were suggested based on the processing map which was constructed from friction and temperature corrected flow curves, determined as 1343 K, 0.02 s-1 and were successfully applied in the canned forging of billets to simulate industrial work condition.在温度1323-1473 K，应变速率0.001-1 s-1的范围内研究了Ti-43Al-4Nb-1.4W-0.6B 合金的热压缩变形行为，其真应力-真应变曲线表明合金在变形过程出现了动态软化行为。依据经过摩擦和温度修正后流变应力的曲线，获得了该合金的本构方程，其中Zener-Holloman指数方程描述了温度和应变速率对变形行为的影响，以此构建五次多项式组来描述应变对材料参数的影响,其预测结果与实验结果相符。同时，建立了该合金的热加工图，并据此加工图预测出该合金合适的加工参数为1343 K和0.02 s-1，且成功地完成了在工业生产条件下对圆柱形试样的锻造。

关 键 词：TiAl alloy flow stress hot deformation constitutive equation processing map 

分 类 号：TG146.23[一般工业技术—材料科学与工程]