硅含量对TIG焊Al-Si/SiCp复合层包覆A380铝合金显微组织的影响

摘要

Tungsten inert gas (TIG) welding was applied to creating a composite layer on the surface of cast aluminum alloy A380. Different mixtures of Al, Si and SiC powders mixed with sodium silicate solution were pasted on substrates. Surface melting was conducted by TIG welding to produce Al-SiC layer on the surface. Microstructural evolution was investigated by X-ray diffractometry (XRD), optical and scanning electron microscopy (SEM) and elemental microanalysis (EDS). Properties of clad layers were studied by microhardness and sliding wear testing. The results showed a uniform distribution of SiC particles in dendritic aluminum matrix. Addition of excess silicon caused the formation of eutectic crystals and coarse silicon particles in the clad layer which resulted in higher hardness and wear resistance of clad layers.%采用钨极惰性气体(TIG)在铸态A380铝合金表面制备复合涂层。将Al，Si和SiC粉末混合物与硅酸钠溶液混合后涂覆在基材上，采用TIG焊进行表面熔化，在基体表面制备Al-SiC涂层。采用XRD、SEM和EDS研究显微组织的变化，采用显微硬度和滑动磨损试验研究包覆层的性能。结果表明，SiC 粒子均匀分布在树枝状的铝基体中。加入过量的硅造成包覆层共晶和粗大硅粒子的形成，从而导致包覆层具有较高的硬度和耐磨性。