定向凝固速度对Cu-Cr合金组织形貌的影响

Effect of Solidification Rates on the Microstructure Morphology of the Cu-Cr Alloy

在高梯度定向凝固装置上制备Cu-1·0%Cr(质量分数)合金,用金相显微镜、扫描电镜进行微观组织的观察,研究定向凝固速度对Cu-Cr合金微观组织形貌的影响。研究结果表明,Cu-1·0%Cr合金定向凝固组织形貌为:初生α相和(α+β)共晶组织相间生长,宏观上沿凝固方向呈纤维状排列;随着凝固速度的提高,凝固组织随着凝固界面形态的演化,出现胞晶组织→粗树枝晶组织→细树枝晶组织的一系列的形貌变化。

The Cu-1.0wt% Cr alloy was prepared by the high temperature gradient directional solidification equipment. The microstructure and its evolution of directionally solidified Cu-Cr alloy were investigated under the condition of different solidification rates ,by use of optical microscope and SEM. The results show that the microstructures of the directionally solidified Cu-1.0wt% Cr alloy consist of primary α phase and （ α＋ β） eutectics, which are even each other and regular along the directional orientation. The microstructure morphology undergos a series of change from cystiform, thick dendrite to thin dendrite with the increase of solidification rates.