化学成分对定向凝固Al－Cu合金热裂倾向的影响

INFLUENCE OF COMPOSITION ON HOT CRACKING TENDENCY OF DIRECTIONALLY SOLIDIFIED Al-Cu ALLOY

本文提出了热裂倾向评定的半定量等级标准，并进行了不同成分Ａｌ－Ｃｕ合金定向凝固热裂试验。理论计算与试验结果比较，证实了化学成分时定向凝固合金热裂倾向的影响符合凝固过程的收缩补偿理论，以及柱晶组织对形成晶间搭桥的影响。

A semi-quantitative method was proposed to evaluate hot cracking tendency.Hot cracking experiments were carried out in directional solidification device for Al-Cu alloys with different compositions. Through comparision between theoretical calculation and experiment results,it was proved that the influence of alloy composition on hot cracking tendency is in conformity with the accommodation theory of alloy contraction in solidification process.The prediction was also proved by experiments about the effect of columnar grain structure on the interdendritic bridging.