通过热压缩实验研究Cu?13Zn?1Ni?1Sn?1.5Al仿金黄铜在温度为953~1123 K和应变速率为0.001~1 s?1条件下的热变形特征.应力?应变曲线表明,流动应力随着温度的升高和应变速率的降低而降低.在0.01 s?1的恒定应变速率下,当温度达到1073 K时,合金的显微组织中出现动态再结晶晶粒.建立合金在不同应变(ε=0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8)条件下的本构方程并计算其变形激活能.当应变为0.8时,合金的本构方程为=7.22×109[sinh(0.0187σ)]3.67exp[?227.17/(RT)],变形激活能为227.17 kJ/mol.绘制仿金合金在不同应变条件下的功率耗散图和失稳图,得到合金在热压缩工艺中的最佳热变形温度范围为1010~1040 K,应变速率为1 s?1.
The hot deformation characteristics of Cu?13Zn?1Ni?1Sn?1.5Al gold-imitation brass alloy in a temperature range from 953 to 1123 K and a strain rate range from 0.001 to 1 s?1 were investigated by hot compression tests. The stress?strain curves show that the flow stress decreases with the increase of temperature and the decrease of strain rate. The dynamic recrystallization grains appear while the temperature reaches 1073 K at a constant strain rate of 0.01 s?1. The constitutive equation of the alloy was established and its deformation activation energies were obtained at different strains (ε=0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8). When the strain is 0.8, the constitutive equation of the alloy is (ε)=7.22×109[sinh(0.0187σ)]3.67exp[?227.17/(RT)], and the deformation activation energy is 227.17 kJ/mol. The dissipation power maps and instability maps were established at different strains, which suggested that the recommended processing condition for hot compression was in the temperature range of 1010?1040 K with a strain rate of 1 s?1.