外加磁场对陶瓷复合材料性能的影响

Effect of Magnetic Field on Microstructure and Properties of Ceramal Composites

在镍基高温合金等离子弧堆焊过程中引入横向交流磁场,利用磁场的作用来提高堆焊层的性能。在堆焊过程中,调节磁场参数和焊接工艺进行实验,测试了不同参数下的堆焊层硬度、磨损性能以及分析了其显微组织。结果表明,适当磁场参数产生的电磁搅拌可以细化堆焊层的组织,而且还能控制堆焊层中陶瓷复合材料的数量、形态及分布情况,从而改善了堆焊层金属的硬度和耐磨性。此外,电磁搅拌还能减小堆焊层化学成分不均匀性,提高堆焊层的塑性和韧性,降低结晶裂纹和气孔的敏感性,从而提高了堆焊层的综合力学性能。

The nickel based superalloy was deposited on low carbon steel by plasma arc surfacing with transverse magnetic field. The properties of the surfacing layer was improved by the effect of magnetic field. The parameters of magnetic field and welding were altered during welding process. The wear loss test,micro-hardness test and microstructure of the samples were used to analyze the effect of magnetic field on properties of surfacing layers. The results indicate that,electromagnetic stirring under proper magnetic field parameters can control the quantity,shape and distribution of ceramal composites,which can improve the strength and wear resistance of the surfacing layer. It can also minish the heterogeneity of primary crystallization structure,improve the plasticity and toughness of surfacing layer,and reduce the sensitivity of cracking and pore.