稀土提高铁基自熔合金喷焊层耐磨性的效果与机理

随着表面技术的发展，稀土元素在表面工程中的应用日益受到人们的广泛重视。为了充分发挥我国稀土资源丰富的优势，不断地开拓其新的应用领域，在铁基自熔合金粉末中添加不同量的混合稀土硅铁合金，采用火焰喷焊技术获得涂层，通过摩擦磨损试验和精细的扫描和透射电子显微镜分析，深入地研究了稀土元素对铁基自熔合金涂层组织结构与耐磨性的影响，以及稀土元素的分布与存在形式，同时还对其作用机理进行了初步分析，研究结果表明，添加适量的稀土元素可以明显地提高喷焊合金层的耐磨性和承载能力；稀土元素能够细化喷焊合金层的组织，形成ＬａＢ６相的沉淀折出而强化基体，并能净化晶界，减少硫在晶界上的偏聚。

The Effect of Rare Earth Elements of Wear Resistance of lron Base Thermal Spray-Welding Coating and lts Mechanism

In recent ycars agreat attention is increasing ly paid to the application of rare earth elements in surface engineering along with the development of this field. This paper,aimingat to make best uses of Chinese rare earth elements resource and develop new application of rare earth elements in surface techniques,the effect of rare earth elements on microstructure and wear resistance of a iron base thermal spray-welding coating produced by a iron-base self-fluxing powder mixed with fractions of rare earth alloy powder was deeply investigated through friction and wear tests and elaborate SEM and TEM analyses,and its mechan ism was discussed based on the distribution and form of existence of rare earth elements in the coatings.The results showed that the addition of an appropriate amount of Si-Fe- Re additive can increase obviously the wear- resistance and load bearing capacity and the mechanisms can be explained by refininggrains,strengthening matrix by precipitation of LaB6 and purify grain boundaries by decrease segregation of element S.