La_2O_3对激光熔覆Fe基合金熔覆层显微组织的影响

Effect of La_2O_3 on Microstructure of Laser Cladding Ferrite-based Alloy Coatings

采用CO2 激光器通过同轴送粉方式 ,在 1 6Mn钢基材上制备了添加La2 O3后的铁基合金熔覆层。通过扫描电镜 (SEM )、能谱 (EDAX)和X射线衍射 (XRD)分析研究了不同稀土加入量对熔覆层组织形貌、元素分布和相组成的影响 ,并利用显微硬度计测量熔覆层的硬度分布 ,同时还研究了稀土对熔覆层夹杂物的影响。结果表明 ,熔覆层中的主要相组成为γ(Fe ,Ni) ,稀土的加入 ,细化了晶粒 ,净化了晶界 ,提高了熔覆层的硬度 。

After adding different contents of La_2O_3,the ferrite-based alloy coatings on the substrate of 16Mn steel were cladded by a CO_2 laser with automatic powder feeding system.The microstructure and elements distribution of the coatings were investigated by scanning electron microscope (SEM) and energy-dispersive analysis of X-rays (EDAX).The phase structure and microhardness of the coatings were measured by X-ray diffraction (XRD) analysis and microhardness tester respectively,the effect of La_2O_3 on the inclusion of the coatings was also studied.The results showed that the main phase of the coating was γ(Fe,Ni).With the addition of La_2O_3,the microstructure of the coatings was refined and purified,the microhardness was increased.Moreover,the microstructure was uniform.