Study On Preparation And Tribological Properties Of（Mg₂B₂O₅w+ND）/ZK60 Composite

The strength, hardness and wear resistance of the magnesium alloy is not ideal, thus limited its application in the civil structural parts. Therefore, this article is intended to prepare magnesium matrix composites with excellent wear resistance, expand its scope of application. Mechanical properties and tribological properties were tested, and wear mechanisms were analyzed.Compact ZK60 alloy, 1wt.%ND/ZK60,(1wt.%Mg2B2O5w+1wt.%ND)/ ZK60 and(2wt.%Mg2B2O5w+1wt.%ND)/ZK60 composites were prepared by powder metallurgy method. It found that grain refinement obviously with the increase of reinforcement mass fraction. Through XRD analysis found no interfacial reaction between the substrate and reinforcement.Through mechanical properties test found that hardness of materials showed an increasing trend with the increase of reinforcement mass fraction, the maximum is 99 HBS. And the elongation showed a decreasing trend. Both ultimate tensile strength and yield strength of 1wt.%ND/ZK60 composite are best, they are 272.0 MPa and 175.9 MPa, respectively. With whiskers added, fracture mechanisms of composites are brittle fracture caused by defects.Under the condition of dry sliding tribological, weight wear rates of materials showed a decreasing trend with the increase of rotational speed, and increase with the increase of load. Besides, weight wear rates of magnesium alloy matrix lower than composites in general. With the increase of rotational speed and load, the wear mechanism transform from abrasive wear as the leading to peeling wear is dominant.Under the condition of lubrication sliding tribological, weight wear rates of materials increase with the increase of rotational speed, when the speed of 900 r/min to peak, and then slightly reduced. With the increase of load, weight wear rates of various materials increase obviously. Weight wear rates of composites lower than the magnesium alloy matrix. With the increase of rotational speed and load, the wear mechanism transform from abrasive wear to peeling wear.