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利用X射线衍射分析方法分析了高压下凝固的Al-Ni-Y合金的相组成;利用光学显微镜对在不同条件下制备的高压凝固合金的显微组织形貌和共晶组织形貌进行研究;通过显微硬度测试方法,确定出冷却速度与显微硬度之间的关系。实验结果表明,高压条件下凝固的合金共晶点发生偏移,使得常压共晶成分的合金在高压下变成亚共晶成分合金。在5 GPa超高压力、不同冷速(50、100、200 K/min)条件下凝固的合金的显微组织形貌发生了很大的改变,但是合金的相组成没有发生变化。随着冷却速率的不断提高,合金组织逐渐细化,二次枝晶间距也随之减小,共晶团尺寸也更加细小,显微硬度提高,Al3Y相的各向异性逐渐减弱。
The phase composition of Al-Ni-Y alloy solidified under high pressure was analyzed by X-ray diffraction analysis. The microstructure and eutectic structure of high-pressure solidified alloy prepared under different conditions were studied by optical microscope. Through the microhardness test method, the relationship between the cooling rate and the microhardness is determined. Experimental results show that the eutectic point of alloy solidified under high pressure is shifted so that the alloy under normal pressure becomes a hypo-eutectic alloy under high pressure. The microstructure of the alloy solidified under 5 GPa ultra-high pressure and different cooling rates (50,100,200 K / min) has been greatly changed, but the phase composition of the alloy has not changed. With the increasing of the cooling rate, the microstructure of the alloy gradually refined, the secondary dendrite spacing also decreased, the eutectic size was smaller, the microhardness increased, and the anisotropy of the Al3Y phase decreased gradually.