LC9铝合金形变过程的声发射研究

LC9铝合金形变过程的声发射研究 STUDY OF ACOUSTIC EMISSION OF LC9 ALUMINIUM ALLOY DURING DEFORMATION 徐约黄 Xu Yaehuang and Huang Daqian first-author 黄大千 研究了几种不同热处理状态的LC 9 铝合金在形变过程中的声发射行为,应变率为0.53毫米/分,实测结果是:（1）完全退火状态,连续声发射在屈服区有最大值,整个形变阶段有丰富的声突发。（2）淬火状态,声发射特别活跃;淬火后自然时效1小时的声发射总计数高达4.5×10 6 ,随着时效时间增长,发声射总计数逐渐下降,到2733小时,总计数降到1.2×10 5 ,同时,连续型声发射也在屈服区出现峰值,此峰随时效时间增长而向高应力移动。（8）淬火经时效强化后,声发射主要出现在弹性形变阶段。过时效状态,声发射变得十分"安静",总计数仅1.0×10 3 .就以上实验结果对退火状态及淬火状态的形变机制进行了初步探讨。 A study of the effect of heat treatment on the acoustic emission（AE）of LC9 Al alloy was carried out during deformation at constant rate of 0.53mm/min. The results are: （1）For a well annealed specimen the continuous AE maximun appeared by the yielding point with numerous bursts over the whole runge of deformation, （2）The specimen as-quenched was very "noisy", room temperature aging for 1 hr after quenching, ringdown total counts reached 4.5×10 6 which was gradually reduced with prolonged aging being 1.2×10 5 after 2733 hr. A continuous AE maximun occured by the yield point, which shifted to the higher stress side with prolonged aging. （3）In an agehardened specimen, AE exist ed mainly in the elastic deformation stage. For an over-aged specimen, it became "quiet", ringdown total counts being 1.0×10 3 only. Observations of microstructure and topographic surface of fracture were performed in paralled with AE measurements. The mechanism of AE sourse was briefly discussed. 1982-01-01 2021-04-01 1