【摘要】 选用优化的激光工艺参数 ,利用激光熔覆工艺在中碳钢表面原位合成硬质陶瓷颗粒增强金属基复合材料涂层 ,涂层熔覆质量良好。涂层是由粘结金属基体和弥散分布于其中的稳定和亚稳定硬质颗粒增强相组成。激光熔覆涂层相对于中碳钢基体强化效果显著。对熔覆涂层的显微分析表明 :涂层中存在细晶强化、硬质颗粒弥散强化、固溶强化和位错堆积强化等强化机制。更多还原

【Abstract】 In-situ synthesized hard ceramic particles reinforced metal matrix composite (MMC) coating was obtained on medium carbon steel substra te by laser cladding with optimal laser parameters.The microhardness of the clad ding layer was measured.The microstructures of the coating were analyzed by op ti cal microscope,SEM and TEM,and XRD was used to examine the phases in the claddin g layer.The results show that the surface quality of the cladding layer is fairly good. The coating is composed of the bonding metal matrix and the sta ble or metastable hardy particle reinforcements dispersing homogeneously in it. The strengthening effect of the cladding layer is significant compared with the me dium carbon steel matrix. Microanalysis to the cladding layer shows that the str engthening mechanisms for the coating are the combination of fine grain streng thening, hard particles dispersing strengthening, solid solution strengthening a nd dislocation pile-up strengthening.更多还原