Al-Cu-Mg-Ag系高强耐热合金的热加工工艺研究

Hot Working Process of a High Strength Heat Resisting Al-Cu-Mg-Ag Alloy

通过差热分析（DTA）、金相组织观察、热模拟及拉伸试验等手段,分析了不同均匀化退火工艺对含Ag的Al-Cu-Mg-（Ag）-Mn-Zr新型耐热铝合金的微观组织和力学性能的影响.结果表明,采用接近低熔点共晶熔化温度的均匀化退火后,合金的枝晶偏析得以消除,晶内成分分布均匀.在470℃、490℃两个温度条件下分别以30%、50%的压下量热轧模拟,证明在470℃条件50%压下量热轧,轧出的板材效果最好,其室温抗拉强度达到470MPa,对应的伸长率达到8%～10%.

Effects of the homogenizing process on the microstructure and mechanical properties of a high strength heat resisting Al-Cu-Mg-Ag-Mn-Zr alloy were investigated by differential thermal analysis （DTA）, optical microscopy, thermal simulation and tensile test. The results show that if homogenized at the temperature closing to the melting point of the non-equilibrium eutectic phases, the Al-Cu-Mg-Ag-Mn-Zr alloy can obtain fine grain boundaries and almost no dendritic segregation structure. Through the thermal simulating tests respectively at the temperature of 470℃ and 490℃ with the reduction of 39% and 50% ,it is show that the appropriate hot rolling process for the tested alloy is rolling at 470℃ with the reduction of 50%. Rolled with the optimized process, the tensile strength of this alloy can reach 470MPa with the elongation of about 8%-10%.