镁合金表面激光等离子复合喷涂NiAl/Al_2O_3涂层的研究  

The NiAl/Al_2O_3 Coatings Prepared by Laser Plasma Hybrid Spraying on Magnesium Alloy

作　　者：钱建刚[1] 栾海静[1] 张家祥[1,2] 王纯[2] 李淑青[2] 

机构地区：[1]北京航空航天大学,北京100191 [2]中航工业北京航空制造工程研究所,北京100024

出　　处：《稀有金属材料与工程》2013年第S2期496-499,共4页Rare Metal Materials and Engineering

基　　金：航空科学基金(20085451039)

摘　　要：采用激光等离子复合喷涂技术在AZ91D镁合金表面成功制备出了性能优异的NiAl/Al2O3涂层,并利用SEM、XRD、光学显微镜法、万能材料试验机和显微硬度计等分析测试手段,研究了在不同激光功率下的涂层的形貌、相组成、孔隙率、结合强度和显微硬度。结果表明:激光等离子复合喷涂NiAl/Al2O3涂层表面致密光滑;涂层由γ-Al2O3和α-Al2O3两种相组成,随激光功率的增加,亚稳态γ-Al2O3相相对含量减少;涂层与基体间呈现冶金结合特征,结合强度最高为29.8 MPa;涂层具有较低的孔隙率,在激光功率为700 W时涂层具有最低孔隙率值为2.5%;喷涂后由基体硬度的HV0.05650 MPa提高到涂层表面硬度的HV0.054700 MPa。NiAl/Al2O3 coating with excellent performance was fabricated by laser plasma hybrid spraying on an AZ91D Mg alloy substrate.By using scanning electron microscopy(SEM),X-ray diffraction(XRD),optical microscopy,universal testing machine and micro hardness tester,the morphology,phase composition,porosity,bonding strength and microhardness of the coatings made under different laser power were studied,respectively.The results show that the NiAl/Al2O3 coating has a smooth and dense morphology; the coating is composed of γ-Al2O3 phase and α-Al2O3 phase,and the content of the γ-Al2O3 phase will decrease with the increases of the laser power; a metallurgical bonding appears between the coating and the substrate.The maximum bonding strength is 29.8 MPa; the porosity ratio of the coating is low and the lowest value is about 2.5% at 700 W of the laser power; the hardness is improved from HV0.05 650 MPa of the substrate to HV0.05 4700 MPa of the coating after spraying.

关 键 词：激光等离子复合喷涂 镁合金 NiAl/Al2O3涂层 激光功率 等离子喷涂 

分 类 号：TG174.4[金属学及工艺—金属表面处理]