CAJ | 학술논문

采用形变热处理法制备2A97铝锂合金细晶板材，利用光学显微镜、透射电镜和高温拉伸等试验方法研究中间退火温度对板材晶粒细化和超塑性的影响。结果表明：板材在室温轧制时，当变形量达到22%时，出现开裂，随着轧制温度的升高，开裂程度逐步缓解；将开轧温度提高到400℃、轧制变形量达到88%时，分别在240、300和400℃进行中间退火1 h，可解决开裂问题。但退火温度对超塑性伸长率有很大影响，当退火温度为400℃时，合金发生了明显部分再结晶，位错密度大幅降低，虽获得总变形量为92%的无开裂板材，由于较多的形变储能被释放，晶粒细化程度不高，伸长率仅为260%；将退火温度降低到240℃时，合金内部仅发生了位错运动与重新组合，保留了较高的位错密度，晶粒得到细化，伸长率高达650%。
채용형변열처리법제비2A97려리합금세정판재，이용광학현미경、투사전경화고온랍신등시험방법연구중간퇴화온도대판재정립세화화초소성적영향。결과표명：판재재실온알제시，당변형량체도22%시，출현개렬，수착알제온도적승고，개렬정도축보완해；장개알온도제고도400℃、알제변형량체도88%시，분별재240、300화400℃진행중간퇴화1 h，가해결개렬문제。단퇴화온도대초소성신장솔유흔대영향，당퇴화온도위400℃시，합금발생료명현부분재결정，위착밀도대폭강저，수획득총변형량위92%적무개렬판재，유우교다적형변저능피석방，정립세화정도불고，신장솔부위260%；장퇴화온도강저도240℃시，합금내부부발생료위착운동여중신조합，보류료교고적위착밀도，정립득도세화，신장솔고체650%。
Fine-grained 2A97 alloy sheets were produced by thermo-mechanical processing. The effects of intermediate annealing temperature on the grain refinement and superplasticity were investigated by optical microscopy (OM), transmission electron microscopy (TEM) and high temperature tensile test. The results show that the fracture of sheet is observed when rolling at room temperature with a reduction of 22%. With increasing the rolling temperature, the degree of cracking gradually reduces. Non-fractured sheets can be obtained by enhancing the preheating temperature to 400℃, and then intermediate annealing the sheets for 1 h at 240, 300 and 400℃, respectively, when the rolling reduction reaches 88%. But the reheating temperatures have an obvious influence on the superplastic elongation. When the reheating temperature is 400℃, the obvious recrystallization occurs, which reduces the density of dislocations. Though non-fractured sheets with a total reduction of 92% are obtained, the superplastic elongation only reaches 260%, because of more deformation stored energy released and low grain refinement. High density of dislocations and a superplastic elongation of 650% are obtained when the reheating temperature decreases to 240℃, during which only the movement and reconfiguration of dislocations happen.