锡青铜网增强锡青铜基自润滑复合材料的机械和摩擦学性能研究

Study on Mechanical and tribological Properties of Tin-Bronze-Net Reinforced Tin-Bronze-Matrix Self-Lubricating Composites

采用粉末冶金工艺制备了锡青铜网增强的锡青铜基自润滑复合材料,考察了锡青铜网对复合材料机械性能和摩擦学性能的影响.研究表明:锡青铜网对研制材料的增强作用主要是由于锡青铜网与基体界面相容性良好,热膨胀系数相近,界面结合强度高,从而减少了增强体与基体之间的裂纹或空隙,且网状金属丝间的筋结与支撑提高了材料的断裂能所致;加入一定量的金属网片提高了材料的耐磨性,但金属网片含量过高会导致转移膜的破坏,从而增大摩擦系数,降低复合材料的强度和耐磨性能.

Tinbronze net reinforced tin bronzematrix selflubricating composites were prepared by powder metallurgy process. The influence of the tinbronze net as the reinforcing agent on the mechanical and tribological behaviors of the composites was investigated. Thus the hardness and crushing and bending strengths of the composites were measured, while their friction and wear behaviors sliding against SAE52100 steel counterpart evaluated on an MM200 friction and wear tester in a ballondisc configuration. The worn surface morphologies of the steel sliding against the tinbronzematrix composites of different compositions were observed on a scanning electron microscope, and the action mechanism of the reinforcing agent and wear mechanisms of the composite discussed accordingly. It was found that he incorporation of the tinbronze net at proper volume fractions contributed to considerably improve the mechanical and tribological behaviors of the tin bronzematrix selflubricating composites, which was attributed to the good interfacial compatibility and interaction between the tinbronze net and the matrix of similar nature and composition. Moreover, the loadsupporting action of the reinforcing metallic net also contributed to increase the mechanical strength and wearresistance of the composites. However, the composites of too high volume fractions of the reinforcing metallic net showed relatively poor wearresistance, which was related to the increased interfacial defects and decreased interfacial bonding of the composites in this case. The tin bronzematrix selflubricating composites were characterized by adhesion wear in unlubricated sliding against the steel, while their tribological behaviors were closely dependent on the characteristics of the transfer films on the counterpart steel surface.