激光功率对液压油缸内壁铜合金熔覆层组织及性能的影响OA

The inner wall of hydraulic cylinders is prone to wear and corrosion damage in high-friction and corrosive underground environments.In this study,a copper alloy coating was fabricated on 27SiMn steel via high-speed laser cladding.By combining experiments with simulations,the molten pool temperature distribution,coating macroscopic morphology,microstructure,and wear and corrosion resistance under different laser powers were systematically analyzed.The results indicate that as the laser power increases,both the maximum temperature and the high-temperature region of the molten pool continuously expand.The coating microstructure mainly consists of dendrites and acicular structures,and the grain size exhibits a trend of first decreasing and then increasing with rising laser power.At the higher power of 2 500 W,a thick layer of coarse dendrites appears at the top of the coating.The microhardness of the coating first increases and then decreases with increasing laser power,reaching the highest value with good uniformity at 2 300 W.Based on the comprehensive friction/wear results,along with electrochemical corrosion analysis,the optimal process parameters are determined as follows:laser power of 2 300 W,scanning speed of 28 mm/s,powder feed rate of 24 g/min,and overlap ratio of 70%.This study reveals the influence of laser power on the microstructure and comprehensive properties of laser-cladded copper alloy coatings,providing technical guidance for the high-quality repair of hydraulic cylinder inner walls via laser cladding.