Preparation Of Lightweight Zinc Matrix Composites For Wear-Resistant Bushings And Research On Friction And Wear Properties

As an important component of the drive shaft of the shearer,the shaft sleeve has different degrees of wear and tear,so new materials are needed to replace the existing shaft sleeve materials and a new preparation process is explored.Using zinc-based rich aluminum alloy instead of other materials as the material of the shearer bushing is a better way of thinking in the process of preparing the bushing.In this paper,the surface metallized carbon fibers were prepared by electroplating,and the phase and microscopic morphology of the carbon fibers before and after nickel plating were compared and analyzed.A new type of zinc-based aluminum alloy-rich composite material was prepared by SPS spark plasma sintering technology,and the microstructure,element structure distribution and phase composition of the composite material were systematically studied to explore the effect of different volume fractions of Ni-Cf reinforcement on the composite material.The effect of material structure and mechanical properties.The wear resistance of the prepared composites was further characterized,and the mechanism of wear reduction and wear resistance was analyzed.The main contents of this article are as follows.The method of electroplating process and by controlling the current,voltage,electroplating time and temperature of the plating solution are used to coat a nickel layer on the surface of the carbon fiber,thereby improving the interfacial compatibility between the carbon fiber and the matrix material,and enhancing the chopped carbon fiber in the ZA27 matrix material.The distribution is uniform and the formation of brittle metal carbide reaction layers is suppressed.The phase,surface and cross-sectional morphology of carbon fibers before and after nickel plating were compared and analyzed,and it was found that the plated nickel layer was evenly distributed around the carbon fibers and tightly attached to the surf-ace of the carbon fibers.The average thickness of the nickel layer was about 817.4 nm,indicating that the nickel coating was complete.The structure of the shell is formed by wrapping the carbon fiber,the coating is thin and the nickel particles on the surface are uniform and dense.Using spark plasma sintering technology,by adjusting the sintering process parameters and the volume fraction of Ni-Cf reinforcements,Ni-Cf/ZA27 composites with different contents of reinforcements were prepared.Elemental distribution and expanded analysis of hardness and density.The metallization of the fiber surface can effectively prevent the quality loss of carbon fibers during high temperature sintering,and form an intermetallic compound Al3Ni with the ZA27 matrix alloy at the interface.Interfacial compatibility of carbon fibers with matrix materials.When the volume fraction of carbon fiber is 6 vol.%,the hardness of Ni-Cf/ZA27 composite is 132HV,which is 29.6%higher than that of ZA27 alloy.This is because the carbon fiber itself is harder than the matrix material,and at the same time,the carbon fiber has a higher strength,and the addition of the ZA27 matrix plays a role in the second phase strengthening.Through the friction and wear test of four Ni-Cf/ZA27 composites with different volume fractions,the wear surface and wear debris morphology of each material were compared and analyzed,and the wear mechanism of Ni-Cf/ZA27 composites under the test conditions was obtained.The results show that the addition of carbon fiber significantly enhances the wear resistance of ZA27 alloy material.When the carbon fiber content is 6vol.%,the friction coefficient of Ni-Cf/ZA27 composite material drops to 0.367,which is higher than the friction coefficient of ZA27 alloy.The wear rate is reduced by 18.4%;the wear rate is reduced to 0.376mm3N-1m-1,which is 96%lower than that of the ZA27 alloy.These improvements are due to the addition of carbon fibers to enhance the hardness of the composite material,thereby improving the plastic deformation resistance of the material,and reducing the metal-to-metal contact between the materials during friction,hindering the deformation of the matrix,thereby optimizing the material in the process of friction.Friction and wear performance under low speed and heavy load conditions.Finally,the paper analyzes and expounds the effect of different carbon fiber additions on the friction and wear properties of composites at high temperature and discusses the friction and wear mechanism under this working condition.