【摘要】 <正> 本文目的是研究定向凝固合金中滑移形变与显微组织的关系,并讨论定向凝固合金的微观结构及柱状晶晶界平直度对裂纹传播和断裂的影响。更多还原

【Abstract】 Directionally solidified DZ-38G superalloy was in situ observed under SEM in order to obtain a better understanding of its slip deformation and fracture process. The slips initiate in matrix and eutectic, and they are able to be transmitted by the eutectic. The slips on dendrite arms are much obvious than those in the interdendritic areas. The slip direction may slightly alter with the change of columnar grain orientation. The microcracks are prone to initiate at transverse grain boundarie, carbides on grain boundaries or eutectic/matrix interfaces. A microcrack usually propagates along a zig-zag path, and it is controlled by the maximum shear stress and tensile stress. The propagation of cracks is closely related to the straightness of columnar grain boundaries.更多还原