(Cr,Fe)_7C_3颗粒束增强铁基复合材料的微观组织及耐磨性

Microstructure and Wear Resistance of Iron Matrix Composites Reinforced by In-Situ Carbides

为了获得耐磨性较好且呈规律分布的碳化铬颗粒束增强铁基复合材料,采用铸渗-热处理法将纯铬丝与白口铸铁进行原位反应,制备了(Fe,Cr)7C3颗粒束增强铁基复合材料。采用XRD和SEM对不同保温时间所得复合材料进行物相分析和微观组织观察,同时测试了其硬度及相对耐磨性。结果表明:复合材料颗粒束内的主要物相组成为α-Fe,γ-Fe和(Fe,Cr)7C3,且随着保温时间的延长,(Fe,Cr)7C3颗粒束的面积逐渐增大,束内组织形态由共晶向亚共晶转变;复合材料具有高硬度和优良的耐磨性。

Fe-matrix composites reinforced by( Fe,Cr) 7 C 3 particulates were prepared by infiltration casting of pure Cr wire and white cast iron participating in in-situ reaction and subsequent heat treatment. The phase composition and microstructure of as-fabricated Fe-matrix composites obtained after different duration of heat-treatment were investigated by means of X-ray diffraction and scanning electron microscopy; and their hardness and wear resistance were also evaluated. Results indicated that as-fabricated Fe-matrix composites mainly consisted of α-Fe,γ-Fe and( Fe,Cr) 7 C 3; and the area of( Fe,Cr) 7 C 3 particulates tended to gradually rise with increasing heat-treatment time,accompanied by eutectic to hypoeutectic transformation. In one word,as-prepared Fe-matrix composites possessed high hardness and excellent wear resistance.