La_2O_3对钢基陶瓷涂层组织与性能的影响

Effect of La_2O_3 on Microstructure and Properties of Steel-based Al_2O_3 Ceramic Coating

采用热化学反应法在中碳钢(45钢)基体上,以稀土氧化镧(La2O3)为添加剂,制备Al2O3陶瓷涂层,并对其组织和性能进行测试和分析。结果表明:稀土氧化镧(La2O3)可以改善陶瓷涂层的组织及性能,陶瓷涂层的硬度和耐蚀性明显提高;添加了稀土氧化镧(La2O3)的Al2O3陶瓷涂层,在900℃固化时有MgFeZr3O4、MgSiO3等新相生成;当陶瓷涂层中稀土添加剂(La2O3)含量约为1.19%时,涂层组织更加致密,涂层与基体的冶金结合更加明显,涂层耐蚀性能更好。

A1203 ceramic coating was prepared on the surface of 45 steel substrate by thermo-chemical reaction. The properties of the coating were tested, and the influences of La203 on the microstructure and performance of the coating were studied. The conclusions are as follows： La203 additives can improve the microstructure and enhance the hardness of the coating; The coating＇s macroscopic quality is better if the curing temperature is 900 ℃, La203 can promote the aggregates to carry on the thermo-chemical reaction to produce the ceramics, at the same time MgFeZr304 and MgSiO3 are produced; The ceramic coating with rare earth oxides accounted for 1.19% has the excellent property with good quality of coating appearance, dense tissue and acid resistance, the metallurgical bonding between coating and substrate becomes more obvious.