超音速等离子喷涂NiCr-Cr_3C_2涂层的结构及冲蚀磨损机理  

Microstructure and Erosion Wear of Supersonic Plasma Sprayed NiCr-Cr_3C_2 Coatings

作　　者：杨秀从 李国禄[1] 王海斗[2] 康嘉杰[3] 林丽[1,2] 

机构地区：[1]河北工业大学材料科学与工程学院,天津300130 [2]装甲兵工程学院装备再制造技术国防科技重点实验室,北京100072 [3]中国地质大学工程技术学院,北京100083

出　　处：《表面技术》2016年第9期32-37,共6页Surface Technology

基　　金：国家自然科学基金(51275151);国家973计划(2011CB013405);国家杰出青年科学基金(51125023);河北省自然科学基金(E2016202325)~~

摘　　要：目的改善流体机械部件的耐冲蚀磨损性能。方法采用超音速等离子喷涂(Supersonic Plasma Spraying)系统制备NiCr-Cr_3C_2涂层,通过X射线衍射仪(XRD)分析了喷涂粉末和涂层的物相结构。采用扫描电子显微镜(SEM)及配套的能谱分析仪(EDS)观察和分析了涂层的微观形貌及化学成分。采用透射电子显微镜(TEM)从超微观角度分析了涂层的晶粒结构。采用Image J2x孔隙率计算软件测定了涂层的孔隙率。采用显微硬度仪、纳米压痕仪及万能拉伸试验机分别测定了涂层的显微硬度、弹性模量和结合强度。采用动载磨料试验机进行了冲蚀试验,冲蚀角度为90°,砂浆比为5:8,冲蚀时间为3 h。结果获得的超音速等离子喷涂Ni Cr-Cr_3C_2涂层主要含有NiCr、Cr_3C_2、Cr_7C_3等物相,至少含有单晶、纳米晶、过渡区三个区域。涂层的显微硬度值为911HV0.3,约为基体的3倍,孔隙率为1.4%,结合强度为66 MPa,弹性模量为215.3 GPa。在90°攻角下,涂层的冲蚀磨损失效以疲劳剥落磨损为主。结论用超音速等离子喷涂系统在基体表面制备的Ni Cr-Cr_3C_2涂层具有较好的耐冲蚀磨损性能。Objective To improve the erosion wear resistance of fluid mechanical components. Methods NiCr-Cr3C2 coat- ings were deposited by supersonic plasma spraying system. The phase structure of the powders and coatings were analyzed by XRD. The microstructure and chemical component were observed and analyzed by SEM and EDS. The grain structure was examined by TEM. The porosity was determined by Image J2x porosity calculation software. The microhardness, elastic modulus and bonding strength were also respectively tested by microhardness tester, NANOVEA and universal tensile tester. The erosion test was done by the dynamic load abrasive testing machine, with the erosion Angle at 90°, sands-cement ratio at 5：8, and ero- sion time 3 h. Results The main phase structure of NiCr-Cr3C2 coatings were NiCr, Cr3C2 and Cr7C3. The grain structure were composed of crystal, nanocrystalline, and transition zones. The microhardness of the coatings was 91 I HV0.3. about 3 times of the substrate, and the porosity was 1.4%, the bonding strength was 66 MPa, and the elastic modulus was 215.3 GPa. The main ero- sion mechanism of NiCr-Cr3C2 coatings was fatigue spalling at 90° attack angle. Conclusion The NiCr-Cr3C2 coatings deposited by supersonic plasma spraying system perform good erosion wear resistance.

关 键 词：超音速等离子喷涂 NiCr-Cr3C2涂层 力学性能 冲蚀磨损 微观结构 

分 类 号：TG174.442[金属学及工艺—金属表面处理]