ZL109激光表面改性处理—激光表面合金化

Laser Surface Modification of Al Si Alloy Laser Surface Alloying (LSA)

采用１０ｋＷ的连续横流ＣＯ２激光器在铸造Ａｌ－Ｓｉ合金基主氏上制备了厚度为２．０－２．５ｍｍ的镍合金化改性层。利用ＳＥＭ，ＸＲＤ，ＴＥＭ及ＥＤＸ等分析方法测试了其微观组织和结构。结果表明：合金化涂层是由α－Ａｌ，Ａｌ３Ｎｉ２，Ｎｉ３Ａｌ，ＡｌＮｉ等Ａｌ／Ｎｉ相以及少量Ｓｉ相组成，涂层与基底之间界面两侧存在明显的成分变化，合金化改性层的平均显微硬度为１７９－２３３ＨＶ０．１。

Ni alloy coatings with thickness 2.0～2.5 mm on cast Al Si alloy were obstained using a CO 2 continuous transverse flow laser beam with maximum power of 10 kW. Microstructures and chemical components of Ni alloy coatings were studied using SEM, XRD, TEM and EDX. It is shown that Ni alloy coatings are composed of α Al, Si and kinds of Al/Ni reaction phases such as Al 3Ni 2, Ni 3Al and AlNi. The chemical components are obviously different in both side zones at the interface between coating and substrate. Microhardness and wear resistance tests were also performed: the average microhardness of coatings was around 179～233 HV0.1, which was much higher than that of Al Si alloy. The antiwear property of the LSA modified layers was also greatly improved, and the relative wear resistance was about 4 times as big as that of substrate materials.