感应加热三元硼化物金属陶瓷涂层的组织和性能

Microstructure and Properties of Ternary Boride Cermet Coatings by Induction Heating

目的研究感应加热对三元硼化物Mo2Fe B2陶瓷涂层的组织和性能的影响。方法首先使用氧-乙炔火焰在45#钢表面喷涂Ni60黏性底层,然后再采用反应火焰喷涂技术在黏性底层上制备三元硼化物金属陶瓷涂层,之后利用感应电流对三元硼化物涂层进行加热处理。通过X射线衍射检测、扫描电镜观察、结合强度试验、显微硬度测试和耐磨试验,分析评价感应加热处理后三元硼化物涂层的相组成、显微组织、结合强度、硬度和耐磨性。结果感应加热处理后,金属陶瓷涂层仍然由Mo2Fe B2与基体相α-Fe组成。三元硼化物涂层和Ni60涂层的孔隙与裂纹等缺陷基本消失,Ni60涂层与基体间的孔隙也基本消失。三元硼化物涂层与基体的平均结合强度为60.48 MPa,是未经加热处理的4.6倍。三元硼化物涂层的显微硬度比未经加热处理的涂层高300HV0.1,磨损率为0.83 mg/mm2,是未经加热处理涂层的68%。结论感应加热处理后,三元硼化物涂层的相组成与未经加热涂层的相同。感应加热处理后,三元硼化物涂层及粘结底层的组织更加致密,结合强度、显微硬度和耐磨性均显著提高。

Objective To research the influence of induction heating on the microstmcture and properties of ternary boride Mo2FeB2 cermet coatings. Methods Ni60 viscous sublayer was first sprayed on the surface of 45 # steel by the oxygen-acetylene flame. Then the ternary boride cermet coatings were sprayed on the surface of viscous sublayer by reaction flame spraying technol- ogy. Last, ternary boride coatings were heated using induced current. By X-ray diffraction （XRD）, scarming electron microscope, bonding strength test, microhardness and wear test, the phase composition, microstrucmre, bonding strength, hardness and wear re- sistance of the ternary boride coating were analyzed and evaluated after heat treatment. Results After induction heating processing, metal ceramic coating was still composed of Mo2FeB2 and base phase alpha Fe. The pore and crack of ternary boride coating and Ni60 coating and between Ni60 and base metal almost disappeared. The bonding strength of ternary boride coating and the base metal achieved to an average of 60.48 MPa, 4.6 times of that without heating treatment. Microhardness of ternary boride layer was 300hv0.1 higher than the coating without heating treatment; and the wear rate was 0.83 mg/mm2, 68% of the coating without heating treatment. Conclusion After the induction heating process, the phase composition of ternary boride coating is the same with that of the coating without heating treatment. The organization of ternary boride coating and viscous sublayer are much denser; the bond strength, microhardness and wear resistance are significantly improved.