激光熔覆制备Al-Si-Cu-Fe准晶态合金涂层的研究

本文报道了在氮气气氛下 ,利用激光熔覆Al50 Si15Cu2 0 Fe15准晶粉末制备Al Si Cu Fe准晶态合金涂层。通过选取适当的激光熔覆参数 ,成功的制备了Al Si Cu Fe准晶态合金涂层。X射线衍射 (XRD)分析显示涂层中含有 1/ 1立方类似相α- (Al,Si)CuFe、β -Al(Si)Fe(Cu)相、λ -Al13 Fe4相和Al0 .7Fe3 Si0 .3 相。制备的涂层显微硬度达Hv914 ,α相和 β相中高的Si元素含量和类似相λ -Al13 Fe4的高含量是影响Al Si Cu Fe合金涂层硬度的主要因素。光学显微镜下显示Al Si Cu Fe合金涂层枝晶细密且取向比较一致 ,一次枝晶臂间距约为 2 5 μm ,且有明显的二次枝晶存在 ,二次枝晶臂间距约为 8μm。摩擦学试验显示 ,随着滑动速度的增加 ,涂层与对偶球之间的摩擦系数逐渐降低 ,且趋于稳定。

Preparation of Al-Si-Cu-Fe quasicrystalline alloy coatings by laser cladding

In this paper, the quasicrystalline alloy coatings were prepared by laser cladding Al-Si-Cu-Fe quasicrystalline powders. By using suitable cladding parameters, Al-Si-Cu-Fe quasicrystalline coatings could be produced. X-ray diffraction (XRD) results showed that the phases in the laser cladding coatings were 1/1 cubic approximant α-(Al,Si)CuFe, β-Al(Si)Fe(Cu), λ-Al_1_3Fe_4 and Al_ 0.7Fe_3Si_ 0.3. The surface microhardness of the quasicrystalline alloy coating was about Hv914. This was due to high content of Si both in α and β phases. λ phase was another factor that contributed to the high microhardness of the quasicrystalline alloy coating. OM (Optical Microscope) showed that the dentrites were rather thin and dense, with orientation parallel to each other. The primary arm spacing was about 25μm. The coating also had abundant secondary dentrites and the second arm spacing was about 8μm. Results of tribological test showed that the friction coefficient of the coating and its counter part ball decreased with th