不同压力对气雾化激光熔覆专用合金粉末的影响  

Effects of Different Pressures on Laser Cladding Special Powder Prepared by Gas Atomization

作　　者：郭士锐[1,2] 陈智君[1,2] 张群莉[1,2] 楼程华[1,2] 姚建华[1,2] 

机构地区：[1]特种装备制造与先进加工技术教育部重点实验室(浙江工业大学),浙江杭州310014 [2]浙江工业大学激光加工技术工程研究中心,浙江杭州310014

出　　处：《中国激光》2013年第6期150-155,共6页Chinese Journal of Lasers

基　　金：国家国际科技合作项目(KM-JD-2012002);浙江省重大科技专项重点工业项目(2012C11001);浙江省公益技术应用研究国际科技合作项目(2011C24006)资助课题

摘　　要：气雾化制粉具有球形度高、松装比大和流动性好等特点,适于制备激光熔覆专用合金粉末。采用自行设计的超音速气雾化喷嘴,在热喷涂粉末Ni60的基础上调整粉末材料配比,在不同的雾化气体压力下进行气雾化实验,以获得性能优良的激光熔覆合金粉末。结果表明,当其他条件一定时,雾化气体压力越大,粉末的平均粒度越小,体积4次矩平均径和索特平均直径越小,即颗粒越细;与此同时,粉末的松装比更大,流动性更好,更能满足激光熔覆的要求。但雾化压力不能无限制地增大。经综合考虑,雾化气压取7MPa为较优的气雾化参数。对比在雾化气压为7MPa时制备的镍基粉末与热喷涂Ni60粉末进行相同参数的同轴送粉激光熔覆,发现自制粉末的激光熔覆层平整光滑,没有裂纹和气孔等缺陷,且熔覆层的硬度相差不大。Gas atomization is characterized by higher sphericity, larger apparent density and better fluidity, suitable for preparing laser cladding special powder. Through the ingredient adjustment of thermal spraying powder Ni60, independently designed supersonic nozzle with confined type is put in use for the atomization, and the atomization experiments are performed under different gas atomization pressures, to obtain the laser cladding alloy powder with excellent performances. The results show that with the gas atomization pressure increasing, the particle mean diameter of powder decreases, as well as the volume mean diameter and Sauter mean diameter. Furthermore, the particle size decreases. In addition, the powder with properties of larger apparent density and better fluidity can be achieved to meet the requirement of laser cladding. But the gas atomization pressure might not increase without limit. The optimum gas atomization pressure is 7 MPa comprehensively, under which the experiments of laser cladding with coaxial feeding are carried on. Compared with the coating by cladding thermal spraying powder Ni60 under the same laser cladding parameters, the coating by the cladding self-designed powder embodies a smoother surface without cracks and pores, and the hardnesses of different coatings are approximately the same.

关 键 词：激光技术 激光熔覆 气雾化 粉末 气压 粒径 

分 类 号：TG156.99[金属学及工艺—热处理] TF801.3[金属学及工艺—金属学]