Cr3C2/Ni3Al复合材料的微观组织和室温耐磨性

采用药芯焊丝法制得Ni-Al-Cr3C2复合焊丝,将该焊丝堆焊于工件表面,在堆焊过程中,利用氩弧物理热和Ni-Al反应热,Ni与Al化合反应生成Ni3Al金属间化合物,Cr3C2则发生分解,除少部分C]与Cr]固溶于Ni3Al基体中外,大部分反应重新析出细小的Cr3C2相,均匀地分布于Ni3Al基体中.室温磨粒磨损和微动磨损实验结果表明,Cr3C2/Ni3Al复合材料的耐磨性为Stellite12合金的2倍左右,较高的硬度、高的碳化物体积分数以及碳化物与Ni3Al基体间良好的界面结合力是Cr3C2/Ni3Al复合材料耐磨性优良的主要原因.

Microstructure and Room-Temperature Wear-Resistance of Cr3C2/Ni3Al Composites

Ni-A1l-Cr3C2 welding wire was produced by metal - powder - core technique. When the welding wires were welded on the surface of carbon steel, carbide particles reinforced Ni3Al base composite was formed due to the physical heat of arc and Ni-Al exothermic reaction. Ni reacted with Al to form Ni3Al and Cr3C2 was dissolved during welding. Most of Cr] and C] reacted to form small-dispersed Cr3C2 phase except that a few dissolved into Ni3Al matrix, which strengthened the matrix significantly. The room-temperature abrasive wear and fretting wear tests showed that the wear-resistance of Cr3C2/Ni3Al composite is about two times higher than Stellitel2 alloy that is the typical conventional high-temperature wear-resistant materials. The good wear resistance of Cr3C2/Ni3Al composite coating can be attributed to large volume fraction of carbides, high hardness, and good phases interface bond.