提高高磷铸铁耐磨性的表面镍基激光合金化

Surface laser alloying processing with nickel base powder for improcing abrasiveness of high phosphorus cast iron

通过对高磷铸铁表面进行以镍基合金粉末为主的激光合金化处理，调整铸铁表面层中的成分、组织与结构，探讨激光表面合金化层的硬度与耐磨性．实验结果表明，在激光功率为１．５ｋＷ，扫描速度为５ｍｍ／ｓ时，镍铬硼硅粉末能很好地溶于基材之中，形成明显的合金层与过渡区，溶入的合金元素大多以化合物或固溶体的形式存在，合金层与基材结合良好，未见宏观及微观裂纹，表面硬化层的硬度值大幅度提高，并使耐磨性提高５～７倍．

The hardness and abrasiveness of the alloying layer on the surface of high phosphorus cast iron are investigated by means of surface laser alloying processing with nickel base powder in order to alter the compositions, morphology, and microstructure of surficial layer of the cast iron. Experimental results show that, when laser power is 1.5 kW and its scanning velocity is 5 mm/s, the Ni Cr B Si powder can well be solved in the matrix of cast iron, forming a remarkable alloying layer and transition zone. Alloy elements solved exist in the form of compound or solid solution.The adhesion of alloy layer to the base material is good without any macroscopic and microscopic cracks. The hardness of surficial hardening layer is improved by a big margin, abrasiveness being increased by 5 up to 7 times.