Cu-15Ni-8Sn合金热变形行为及热加工图

Hot deformation behavior and hot processing map of Cu-15Ni-8Sn alloy

利用Gleeble-1500D热力模拟机对Cu-15Ni-8Sn合金进行热压缩试验,研究了该合金在变形温度700~900℃,应变速率为0.003~5 s^(-1),总变形量为60%下的热变形行为和热加工性能。结果表明:合金的流变应力随变形程度的增加先急剧增加到最大值后持续下降,流变应力峰值随温度升高而降低,随应变速率增加而增加。基于合金流变应力曲线关系分别构建了耦合应变的修正的Arrhenius双曲正弦模型和热加工图,并得到合金热变形激活能为195976 J·mol^(-1),试验范围内Cu-15Ni-8Sn合金最佳热加工参数:变形温度800~900℃,应变速率0.003~5 s^(-1)。在较优工艺条件下,合金组织主要由动态再结晶晶粒和变形晶粒组成。

The hot compression experiment of Cu-15 Ni-8 Sn alloy was carried out with Gleeble-1500 D thermal simulator. The hot deformation behavior and hot working properties of the alloy were studied at the deformation temperature of 700-900 ℃, the strain rate of 0.003-5 s^(-1)and the total deformation of 60%. The results show that the flow stress of the alloy increases rapidly to the maximum value and then decreases continuously with the increase of deformation degree, the peak value of the flow stress decreases with the increase of deformation temperature and increases with the increase of strain rate. The modified Arrhenius hyperbolic sinusoidal model of coupled strain and the hot processing map are constructed based on the relationship of flow stress curves of the alloy. The activation energy of hot deformation of the alloy is 195976 J·mol^(-1). The optimal hot processing parameters of the Cu-15 Ni-8 Sn alloy in the experimental range are as follows: the deformation temperature of 800-900 ℃ and the strain rate of 0.003-5 s^(-1). The microstructure of the alloy is mainly composed of dynamic recrystallized grains and deformed grains under the optimum processing conditions.