镍包覆氧化铝增强铁基复合材料的界面行为及其耐磨性(英文)

Interaction Mechanism and Wear Resistance of Niencapsulated Al;O;Particles Reinforced Iron Matrix Composites

采用化学沉积法在Al_(2)O_(3)表面制备了Ni镀层,将所制得的Ni包覆Al_(2)O_(3)颗粒(Al_(2)O_(3)p@Ni)作为铁基体的增强颗粒,采用SPS法制备了镀镍氧化铝增强铁基复合材料(Al_(2)O_(3)p@Ni/Fe)。通过优化化学镀工艺,使得Al_(2)O_(3)表面被Ni层均匀覆盖。Ni镀层呈典型的花椰菜状结构,尺寸为1~4μm,施镀过程中镍首先沉积在Al_(2)O_(3)表面的凹坑和孔洞中,然后逐渐长大向外扩展。Ni镀层与Al_(2)O_(3)紧密结合,厚度可达100μm。在烧结过程中,Ni镀层不仅提高了Al_(2)O_(3)与铁基体之间的润湿性,而且促进了Al_(2)O_(3)与铁基体在界面处的扩散和反应。最终,通过机械结合、扩散反应和冶金反应形成了Al_(2)O_(3)/Ni A1_(2)0_(4)/(Al_(0.8)Cr_(0.2))_(2)O_(3)/Ni Fe_(2)O_(4)/Ni/铁基体界面,大大提高了界面结合强度。同时,对Al_(2)O_(3)p@Ni/Fe复合材料和无表面处理的Al_(2)O_(3)p/Fe复合材料进行了磨损试验,结果表明,与Al_(2)O_(3)p/Fe复合材料相比,Al_(2)O_(3)p@Ni/Fe复合材料的磨损质量损失降低了50%,摩擦系数降低了12.5%。Al_(2)O_(3)p@Ni/Fe复合材料的耐磨性明显提高。

Ni coating was prepared on the surface of Al_(2)O_(3)by chemical deposition method.Ni coated Al_(2)O_(3)particles(Al_(2)O_(3)p@Ni)was used as particle-reinforcement for iron matrix.The Al_(2)O_(3)p@Ni/Fe composites were prepared by SPS.Results show that by optimizing electroless plating process,the surface of Al_(2)O_(3)is uniformly covered by Ni.Ni coating presents a typical cauliflower structure with the size of 1~4(im,which is deposited in pits and holes on the surface of Al_(2)O_(3)and then gradually extends outwardly.The thickness of Ni layer is up to 100.55[im,and Ni coating is closely bounded to Al_(2)O_(3).In the process of sintering,Ni coatings not only improve the wettability between Al_(2)O_(3)and iron matrix,but also promote the diffusion and reaction of Al_(2)O_(3)and iron matrix at the interface.Finally,Al_(2)O_(3)/NiAl_(2)O_(4)/(Al_(0)gCr0_(2))_(2)O_(3)/NiFe_(2)O_(4)/Ni/iron matrix interface layer is formed by mechanical bonding,interdiffusion and chemical reactions,which can improve interface bonding strength greatly.The wear tests of Al_(2)O_(3)p@Ni/Fe composites and Al_(2)O_(3)p/Fe composites were carried out.Compared with Al_(2)O_(3)p/Fe composites,the wear mass loss of Al_(2)O_(3)p@Ni/Fe composites is decreased by 50%,and the friction coefficient is decreased by 12.5%.The wear resistance of Al_(2)O_(3)p@Ni/Fe composites is greatly improved.