Research On Frictional Behavior Of Cu-BN Composite

ABSTRACT: The using of BN in composite can increase the using temperature and application of the self-lubricating copper-based composite material. There are many deficiencies for traditional methods of preparation,such as complicated process,high cost of production and segregation of macro organization and so on. In this study,semi-solid casting forming technology was used to prepare the composite, which successfully solved the problem of lubrication particles’ uneven distribution. At last, the composite’s friction performance in high temperature was studied. The main contents and conclusions were described as follows.1.The method of electromagnetic-mechanical stirring was adopted to prepare semisolid Cu-BN slurry. The relationship between the solid fraction and the size of aggregate graphite is determined and the condition for eliminating macro-segregation of BN in Cu-BN composite is obtained as follows: the solid fraction of the composite slurry is above20%.2.Friction behavior of semi-solid casting copper-graphite composite against45steel under dry sliding is evaluated in the pin-on-disc tribological tester. The relationship between load and friction coefficient is concluded as follows: U=0.0004N+0.2825Meanwhile, the relationship between friction coefficient and friction time is studied. The result is as follows: with the increase of friction time, friction coefficient gradually decrease and then trend steady. After120minutes, friction coefficient keeps basically unchanged.