原位生成碳化铬颗粒增强铁基表面梯度复合材料

(Fe,Cr)_7C_3 Particles Reinforced Iron Matrix Surface Gradient Composite Prepared by In-situ Technology

利用铸渗-热处理法将纯铬板与H7300进行原位反应制备了(Fe,Cr)_7C_3/Fe表面梯度复合材料。应用XRD、SEM和ML-100对1185℃保温不同时间所得的(Fe,Cr)_7C_3/Fe表面梯度复合材料的物相、显微组织和相对耐磨性进行了分析。结果表明:1185℃保温1h后生成的表面梯度复合材料的主要物相组成为(Fe,Cr)_7C_3、α-Fe、(Fe,Cr)_3C及未反应Cr,1185℃保温3 h后主要物相组成变为(Fe,Cr)_7C_3、α-Fe、(Fe,Cr)_3C以及(Fe,Cr)_(23)C_6;表面梯度复合材料表面显微组织由表面至基体呈梯度分布;在5 N载荷120目SiO_2两体磨料磨损下,(Fe,Cr)_7C_3/Fe表面梯度复合材料相对耐磨性有了明显提高,而陶瓷区的相对耐磨性最高,约为HT300的7倍。

（Fe,Cr）TCa/Fe surface gradient composite was prepared with pure chromium plate and HT300 by in-situ synthesis method using cast penetration plus heat treatment. The phase, microstructure and relative wear resistance of the surface gradient composite prepared at 1185℃ for different time were analyzed by XRD, SEM and ML-IO0. The results show that the main phases of the surface gradient composite are composed of （Fe,Cr）TC3,α-Fe, （Fe,Cr）3C and unreacted Cr at 1185℃ for lh, which change to （Fe,Cr）7C3, α-Fe,（Fe,Cr）3C and （Fe,Cr）23C6 at 1185℃ for 3 h. The microstructure distribution of the composite from the surface to the matrix takes the shape of the gradient. The relative wear resistance of （Fe,Cr）7C3/Fe surface gradient composite increases when measuring under 5 N load with 120 mesh in two body abrasion. The ceramic zone has the highest wear resistance, which is 7 times than that of HT300.