6063铝合金挤压型材的TTP曲线测定及其应用研究

摘要

The time-temperature-property ( TTP ) curves for 6063 extrusion aluminum alloy were measured using interrupted quenching technology, the microstructure was observed by transmission electron microscopy ( TEM) and the effect of quenching rate on the hardness of alloy was predicted in conditions of different cooling rate using the quench factor analysis method. The results show that the critical temperature range is 280~410 ℃ with the nose temperature of about 360 ℃. During isothermal treatment process, the equilibrium βphase precipitates from the supersaturated solid solution, and the precipitation rate is the highest at the nose temperature. Prolonging the holding time leads to more and coarser β phase in the matrix. The cooling rate should be more than 15 ℃/s in the quenching sensitivity temperature range during on-line quenching to get optimal mechanical properties and the residual stress could be reduced at the same time.%通过中断淬火技术测定了6063铝合金挤压型材的时间-温度-性能（ TTP ）曲线，并通过透射电子显微镜观察其微观组织，采用淬火因子分析法预测不同淬火速率对合金硬度的影响．研究表明，6063挤压型材的TTP曲线鼻尖温度约为360℃，淬火敏感区间为280～410℃．等温保温时，过饱和固溶体分解析出无强化效果的β平衡相，会削弱时效强化效果，在360℃附近的相变速率最快，随着保温时间的延长，粗大β相数量和尺寸增加．为了在较好的时效强化效果和较小的残余应力之间求得平衡，6063挤压型材在线淬火时，在淬火敏感区间的冷却速度最好略大于15℃/s，高于410℃和低于280℃时可适当降低冷却速率．