稀土Y对6061铝合金铸态组织及性能的影响

The Effect of Y on the As-Cast Microstructure and Properties of 6061 Aluminum Alloy

采用光学显微镜、扫描电子显微镜电镜、拉伸力学测试仪,研究了在6061铝合金中加入稀土Y后,材料铸态组织和性能的影响。结果表明:微量Y元素加入6061铝合金后,铸态组织得到改善,添加0.3 wt.%Y后,晶粒尺寸达到较小值(86.7μm),同时能够有效地形成AI_(3)Y相,在基体中形成弥散强化,部分稀土相在晶界处析出,其制备的6061铝合金棒材的抗拉强度高达360MPa,断裂伸长率为14%,比未添加提高30.43%和5%,断裂方式为韧窝断裂与准解理断裂复合形式。

The effects of rare earth Y addition on the as-cast microstructure and mechanical properties of the 6061 aluminium alloy were studied by optical microscopy,Scanning electron microscope electron microscopy and tensile mechanical tester.The results showed that the as-cast microstructure was improved by adding trace Y into the 6061 aluminium alloy,and the grain size reaches a small value(86.7%)after adding 0.3 wt.%Yμm At the same time,it can effectively form AI_(3)Y phase,form dispersion strengthening in the matrix,and some rare earth phases precipitate at the grain boundary.The tensile strength of 6061 aluminum alloy bars prepared by it is up to 360MPa,and the elongation at break is 14%,which is 30.43%and 5%higher than that without the addition.The fracture mode is a combination of dimple fracture and quasi cleavage fracture.