【摘要】 利用自行研发的送粉等离子束表面冶金涂层设备及Fe-Cr-N i-B-Si-C系混合合金粉末在普通低碳钢表面制备了铁基复合材料涂层。采用OM、SEM、EDS、XRD等手段,研究了同步送粉等离子束表面冶金工艺参数对涂层显微组织的影响及涂层的强韧化机制。结果表明,工作电流、扫描速度以及搭接工艺是影响涂层微观组织特征的重要因素。经工艺优化后的复合材料涂层的典型微观组织由固溶了大量Cr、少量N i、Si的极度过饱和的γ相枝晶及枝晶间复杂合金碳硼化物+γ相共晶组织构成。细晶强化、固溶强化和高硬度相的沉淀析出及其弥散强化是等离子束表面冶金复合材料涂层强韧化的3种主要机制。更多还原

【Abstract】 The Fe-based composite coating was attained with self-designed Fe-Cr-Ni-B-Si-C alloy powders by self-developed DC-Plasma-Jet surface metallurgical equipment.The influence of synchronous powder feeding plasma surface metallurgy processing on the microstructure of the coating and the coating strengthening-toughening mechanism were studied by OM,SEM,EDS and XRD.The results show that working current,scanning velocity,overlapping process are key factors influencing microstructure of the coating.The typical microstructure of the composite coating after optimized processing is composed of γ-Fe dendritic crystal supersaturated solid solution of lot Cr and small amount of Ni,Si elements,and eutectic structure of composite alloy carbides-boride and γ-Fe dispersed on interdendrite.Fine grain strengthening,solution hardening,precipitation and dispersion strengthening are main mechanism of composite coating.更多还原