结晶器铜板上激光熔覆镍基合金

Ni-Based Alloy Cladding on Copper Crystallizer Surface by Laser

利用5kWCO2激光器在结晶器铜板上熔覆镍基合金，并研究了熔覆层组织性能．选用与结晶器铜板成分相近的镍基自熔合金粉末Nickel—base HMSP1015—00（Ni1015），利用等离子喷涂技术在铜板上预涂Ni1015合金，然后再采用高能量密度激光进行重熔．借助OM，SEM和显微硬度计分析测定了涂层的显微组织形貌、组织成分和截面显微硬度分布情况．所得到的熔覆层表面平整均匀，与基体为冶金结合；熔覆层平均显微硬度为270HV0．05，是基体的3．2倍（85HV0．05）．确定出本实验合适的激光熔覆工艺参数：功率密度为1．58×100kW／cm^2时，扫描速度为3～4m／min．

Copper crystallizer surface was clad with Ni-based alloy by a 5 kW-CO2 laser, and the microstructure and mechanical properties of the cladding were analyzed. The powdered Ni1015 alloy was used as dadding material because its composition is similar to that of the copper plate of crystallizer. The alloy was deposited on Cu substrate by virtue of plasma spraying, then remelted by a high-energy density laser at high scanning speed. By using OM, SEM and microhardness tester, the microstructural morphology/composition and microhardness distribution on the cross-section of the cladding were given. The dadding shows smooth and uniform surface and combines metallurgically with Cu substrate, of which the average micmhardness is 270HV0.05, about 3.2 times as high as that of Cu substrate（85HV0.05）. The results showed that in the testing the optimal process parameters of the laser cladding used are that the laser energy density equals 1.58 × 10^2 kW/cm^2 and laser scanning speed equals 3～4 mm/min.