激光熔覆Al65Cu2OCr15准晶态合金的相选择问题

研究了在45#钢基体表面激光熔覆Al65Cu20Cr15准晶态合金过程中，工艺参数激光功率（P）和扫描速度（v)对激光熔覆涂层相结构的影响。结果表明，激光功率和扫描速度的变化使基体材料对熔覆涂层的稀释率发生改变，随着激光熔覆稀释率的增加，熔覆层的相结构依次为λ＋I，I＋β，β，β＋d，d Fe，激光熔覆涂层相结构的差异使涂层具有不同的显微硬度，参数δ（P／v)决定激光熔覆过程的稀释度，从而直接影响激光熔覆准晶涂层的相结构，涂层的表面显微硬度也因涂层相结构的不同而有所差异。

PHASE SELECTION IN LASER CLADDING Al65Cu20Cr15 QUASICRYSTAL COATINGS

The phase selection in Al65Cu20Cr15 quasicrystalline coating produced by laser cladding was studied as a function of the laser power and scanning speed. A parameter S, defined as the ratio of the laser power, P, to the scanning speed, v, has been used to understand the effect of the laser parameters on the phase selection of layer claddings. Experimental results indicated that the icosahedral (i) phase could be formed for low value of 5, and that especially the volume fraction of (i) phase was essentially dependent on the scanning speed. On the contrary, high value of S enabled the formation of the decagonal (d) as a consequence of Fe diffusion from the substrate. The surface microhardness of the cladding coatings is different from each other for specimens prepared with different parameters, owing to the difference of the phase composition.