激光涂覆制备原位自生MoSi_2/SiC陶瓷复合涂层的研究

Investigation of in-situ Synthesis of MoSi_2/SiC Composite Coating by Laser Cladding

为了在碳钢表面获得耐磨、耐蚀、抗热疲劳等综合性能优良的陶瓷基复合涂层 ,利用 3kW连续波快速轴流CO2 激光器进行了一系列的激光表面涂覆试验 ,光斑直径3～5mm ,扫描速度 3～ 10mm/s。试验结果表明 ,利用激光表面涂覆技术和粉末预置法 ,可以在碳钢表面直接原位合成SiC颗粒增韧的MoSi2 陶瓷基复合涂层 ,涂层与基体呈良好的冶金结合 ,涂层宏观质量完好 ,无裂纹和气孔等缺陷。球状SiC颗粒尺寸为 1～ 5 μm ,均匀分布于MoSi2 基体内。涂层显微硬度达 10 0 0HV0 2 ,是基材显微硬度的 4

In order to improve resistance to high temperature and wear resistance of carbon steel,the laser cladding experiments were conducted on a 3kW continuous wave CO 2 laser.The diameter of the laser beam is 3～5mm,the scanning velocity is 3～10mm/s.The experimental results show that MoSi 2/SiCp composites coating can be synthesized in situ from mixture powders of molybdenum,silicide and graphite by laser cladding.A good metallurgical bond between coating and the substrate can be achieved,and the coating is free of crack and gas hole.The microstructures of the coating are composed of MoSi 2,SiC and FeSiMo phases,and the diameter of SiC particle is 1～5μm.The average microhardness of the coating is about 1000HV0 2,3 5 times higher than that of the steel substrate.