无铅易切削黄铜合金高温热压缩流变应力行为  

Flow stress behavior of lead-free machinable brass during high-temperature compression deformation

作　　者：甘春雷[1] 郑开宏[1] 王海艳[1] 戚文军[1] 周楠[1] 蔡畅[1] 

机构地区：[1]广东省工业技术研究院(广州有色金属研究院),广东广州510650

出　　处：《材料研究与应用》2014年第2期97-102,107,共7页Materials Research and Application

基　　金：广东省部产学研结合项目(No.2012B091100038);广州市科技计划项目(7411804513611);广州有色金属研究院博士启动基金(2012B001)

摘　　要：在变形温度为823~973K,应变速率为0.01~1s-1的条件下,采用热压缩实验研究了无铅易切削黄铜合金的高温流变应力行为,结果表明：在所有变形条件下该合金的流变曲线均出现软化现象,这种流变软化主要是由于发生了动态再结晶和β→α相变造成的.基于热压缩试验所得实测数据,建立了材料常数为应变的6次多项式函数的双曲正弦形式的本构模型,与实验数据对比表明,该模型能够较好地预测无铅易切削黄铜合金的流变应力.The hot deformation behaviors of the newly developed lead-free machinable brass are investigated by isothermal compression tests on a Gleeble-1500thermal-mechanics simulator at temperatures of 823-973Kand strain rates ranging from 0.01 to 1s-1.The typical flow curves exhibit softening at all the deformation conditions,which have been considered that the flow softening results from the occurrence of DRX behavior and theβ→αphase transformation of the lead-free machinable brass.On the basis of the experimental data,a new constitutive model with the material constants expressed by a sixth order polynomial fitting of strain was developed through a hyperbolic-sine Arrhenius type equation to relate the flow stress,strain rate and temperature.The flow stresses calculated by the proposed constitutive model are good agreement with the experimental ones.

关 键 词：无铅易切削黄铜合金 热变形 流变应力 本构模型 

分 类 号：TG146.2[一般工业技术—材料科学与工程]