Effects of remelting path on the microstructure defects and properties of in-situ (Ti, W) C/Ni composite coatings
摘要
When laser remelting was used to regulate the microstructure and properties of in-situ (Ti, W)C/Ni composite coatings, in order to achieve better regulation effects, five types of remelting coatings with offset, oblique, vertical, flip and original position scanning path were prepared when the laser energy density E is 1500 J/mm. The cross-sectional morphology, microstructure, phase composition and internal defects of the coating were analyzed by using an optical microscope, a scanning electron microscope (SEM) and an X-ray diffractometer. The hardness, wear resistance and surface flatness of the coating were evaluated by combining a Vickers hardness tester, a friction and wear testing machine and a roughness detector. The research results show that the remelted coatings all have porosity and crack defects of varying degrees except for the original position path. The microstructure uniformity of the remelted coating along the original position trajectory is the best, and its mechanical properties (hardness, wear resistance) and surface flatness are significantly superior to those of other paths.