ECAP变形Al-5Ti中间合金细化纯铝研究

Effect of Al-5Ti Master Alloy with Equal Channel Angular Pressing on Grain Refining of Pure Al

对Al-5Ti中间合金在室温下进行3道次等通道挤压变形（Equal Channel Angular Pressing,ECAP）,将ECAP变形前后的Al-5Ti中间合金添加到纯铝中研究其对纯铝的细化效果。结果表明：TiAl3相由粗大（～270μm）的板条状破碎成细小（～13μm）的颗粒状且分布均匀。随着Ti含量的增加,纯铝晶粒尺寸逐渐减小,当Ti含量达到0.03%以后,晶粒尺寸变化减缓。ECAP变形后能得到的最小晶粒尺寸几乎不变,但形核潜质得到了明显提高。找出了变形前后晶粒尺寸与生长限制因子之间的关系。

Al-5Ti master alloy was subjected to equal channel angular press （ECAP） by three passes at room temperature. The grain refining effect of Al-5Ti master alloy before and after ECAP on pure Al was evaluated. The results show that the large platelet-like TiAl3 particles were fragmented into the fine blocky TiAl3 particles from -270 μm to -13 μm and distributed uniformly in the Al matrix after three ECAP passes. With the increase of Ti contents, the grain size of the industrial purity Al decreases, and when the content of Ti reaches 0.03%, the variation of grain size is small. The minimum grain size is not changed in addition to Al-Ti master alloy by ECAP, however, there is a remarkable enhancement oin the nucleant potency of Al-5Ti alloy. The relationship between the grain size and the growth restriction factor was obtained before and after ECAP, respectively.