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利用CO2 连续激光对预涂石墨和硅混合粉末的Ti 6Al 4V合金进行了熔敷处理。金相分析发现熔敷层内形成了大量的化合物 ,X射线衍射分析证实形成的化合物主要为SiC ,Ti5Si3 和TiC等。电子探针分析表明熔敷层内的初晶化合物主要由SiC和TiC组成 ,共晶化合物则主要是Ti5Si3 。熔敷层与金属基体呈良好的冶金结合 ,其硬度可达 2 0 0 0Hv0 .1,摩擦系数约为 0 3,而基体的硬度约为 32 0Hv0 .1,摩擦系数约 0 5 5。可见熔敷层较基体的硬度大为提高 ,且其耐磨性能较好。激光工艺参数的改变影响着熔敷层的组织和性能 ,调整工艺参数可获得无气孔和裂纹的熔敷层。
The Ti 6Al 4V alloy precoated with graphite and silicon powder was deposited by CO2 continuous laser. Metallographic analysis revealed that a large number of compounds were formed in the cladding layer. X-ray diffraction analysis confirmed that the compounds were mainly composed of SiC, Ti5Si3 and TiC. Electron probe analysis shows that the primary crystal compounds in the cladding layer are mainly composed of SiC and TiC, while the eutectic compounds are mainly Ti5Si3. The cladding layer is metallurgically bonded to the metal substrate with a hardness of 20000Hv0.1, a friction coefficient of about 0.3, and a hardness of about 3200Hv0.1 and a friction coefficient of about 055. It can be seen that the hardness of cladding layer is much higher than that of matrix, and its wear resistance is better. Changes in the laser process parameters affect the structure and properties of the deposited layer. Adjustment of the process parameters results in a weld-free layer with no pores and cracks.