Experimental Study on Ni-Base Alloy Bulk Reinforced by Laser Sintered WC Particles

The basic principle of the formation of high-temperature Ni-base alloy reinforced by tungsten (wolfram) carbide (WC) particles using the technique of direct metal laser sintering (DMLS) was introduced. The effect of different process parameters (laser power, scanning rate) on the micro-topography, composition and micro-hardness of the sintered area is studied by means of scanning electron telescope, X-ray diffractometer and micro-hardness tester. At a laser power of 900 W and a scanning rate of 0.7 m/min, the test shows good laser sintering performance and high sintered density. Meanwhile, it indicates that WC particles are molten into dendritic crystals and evenly dispersed in the matrix, and that the reinforced particles are arrested by the solid-liquid interface. The fact that WC particles are well dispersed in the matrix improves the performance of the bulk sintering. According to the test, we have obtained a set of optimal process parameters in production of sintered metal bulks, high in hardness and compact in construction. (C) Koninklijke Brill NV, Leiden, 2011