CAJ | 학술논문

采用硬度测试、拉伸性能测试、DSC分析和透射电镜(TEM)等方法研究不同时效制度对2A97铝锂合金组织和性能的影响。结果表明：采用165℃人工时效时，峰值强度最高，但其塑性也最差，且达到峰值的时间长达60 h；200℃人工时效时，达到峰值的时间缩短为6 h，而其峰值强度和塑性均很差；(200℃,6 h)+(165℃,6 h)双级时效优化后，可获得比200℃峰时效更高的强度，其抗拉强度为545 MPa，只比165℃峰时效强度低11 MPa，伸长率却提高至7.1%，且时效时间比165℃峰时效时缩短了48 h。2A97铝锂合金峰时效状态下的析出相有T1(Al2CuLi)相、θ′相和一定量的σ(Al5Cu6Mg2)相。根据不同升温速率下的DSC曲线，采用Kissinger法求得T1相的析出激活能为75.9 kJ/mol。综合分析可知，采用(200℃,6 h)+(165℃,6 h)双级时效可以得到比单级时效更加优异的综合性能。
채용경도측시、랍신성능측시、DSC분석화투사전경(TEM)등방법연구불동시효제도대2A97려리합금조직화성능적영향。결과표명：채용165℃인공시효시，봉치강도최고，단기소성야최차，차체도봉치적시간장체60 h；200℃인공시효시，체도봉치적시간축단위6 h，이기봉치강도화소성균흔차；(200℃,6 h)+(165℃,6 h)쌍급시효우화후，가획득비200℃봉시효경고적강도，기항랍강도위545 MPa，지비165℃봉시효강도저11 MPa，신장솔각제고지7.1%，차시효시간비165℃봉시효시축단료48 h。2A97려리합금봉시효상태하적석출상유T1(Al2CuLi)상、θ′상화일정량적σ(Al5Cu6Mg2)상。근거불동승온속솔하적DSC곡선，채용Kissinger법구득T1상적석출격활능위75.9 kJ/mol。종합분석가지，채용(200℃,6 h)+(165℃,6 h)쌍급시효가이득도비단급시효경가우이적종합성능。
The effect of aging treatment on the microstructure and mechanical properties of 2A97 Al-Li alloy during artificial aging was studied by hardness measurement, tensile test, differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). The results indicate that 2A97 alloy obtains the highest strength, but its elongation is relatively low when aged at 165℃for 60 h;when it is aged at 200℃, only 6 h is needed to achieve peak aging, whereas the peak strength and elongation are both poor;when the alloy is aged at (200℃, 6 h)+(165℃, 6 h), the aging time of which is 48 h less than that of single aging treatment when peak values are obtained, while the tensile strength is 545 MPa, only 11 MPa less than that of single aging treatment, and the elongation increases to 7.1%. The T1(Al2CuLi) phase, θ' phase and σ(Al5Cu6Mg2) phase are the major precipitates in 2A97 alloy. According to the DSC curves at various heating rates, the activation energies of T1 phases by Kissinger method is 75.9 kJ/mol. To sum up, the (200℃, 6 h)+(165℃, 6 h) double aging treatment can endow the alloy with more excellent comprehensive performance than single aging system.