粉煤灰活性氩弧熔覆Al2O3-TiB2-TiC复合涂层组织和性能分析

以铁基合金粉末、Al、TiO2和B4 C粉末为涂覆材料,以高铝粉煤灰、SiO2、MgO、CaF2和CeO2为活性剂,采用活性氩弧熔覆技术在Q235钢表面原位合成Al2O3-TiB2-TiC颗粒增强铁基复合涂层.测试熔覆涂层的物相结构、金相组织、显微硬度和耐磨性能,并与未涂覆活性剂的常规熔覆涂层进行对比分析.结果表明,复合涂层由Al2O3、TiB2、TiC、FeSi2 Ti、FeB2和α-Fe相组成,其与基体界面无气孔、裂纹等缺陷,呈良好的冶金结合;复合涂层测试点的最高显微硬度为1283.4 HV0.2,其在室温干滑动磨损条件下耐磨性良好;粉煤灰复合活性剂的加入可以促进熔覆层与母材之间的良好熔合、增加涂层中新相种类和数目、提高氩弧熔覆效率,这对改善复合涂层的综合性能具有重要意义.

Analysis of Microstructure and Properties of Al2O3-TiB2-TiC Composite Coating Prepared by Activating Argon Arc Cladding of Fly Ash

Using Fe-based alloy powder,Al,TiO2 and B4 C as coated materials and high-alumina fly ash, SiO2 ,MgO,CaF2 and CeO2 as activating flux,the Fe-based composite coating reinforced by in-situ synthesized Al2O3-TiB2-TiC particulates was prepared on the surface of Q235 steel by activating argon arc cladding technology. The phase,microstructure,microhardness and wear resistance of composite coating were analyzed and compared with conventional cladding coating which didn't coat activating flux. The result shows that the phases of composite coating consists of Al2O3 ,TiB2 ,TiC,FeSi2 Ti,FeB2 andα-Fe. The interface between the coating and substrate has excellent bonding without pores and cracks. The maximum microhardness of the coating is 1283. 4 HV0. 2 . Wear test results indicate that the composite coating has excellent wear resistance in the condition of dry sliding wear at room temperature. Fly ash composite activating flux can promote better fusion of cladding coating and the substrate,increase the types and numbers of new phase and improve the efficiency of argon arc cladding,which is of great significance to improve the comprehensive properties of composite coating.