Wear-resisting Characteristics Research Of Recycled WC_p/Fe-C Composite Material

This paper investigated the microstructures, mechanical properties and frictionalwear character of recycled composite material samples prepared by the centrifugalcasting of WC_P/Fe-C composite roller scraps after the remelting treatment, used byJB147/294A-type impact test machine, HR-150D Rockwell hardness, MMS-1Gfriction and wear machine, JSM-5610LV scanning electron microscopy(SEM), energydispersive spectroscopy (EDS); observed wear morphology detailedly and analyzedthe wear mechanism by SEM and EDS equipment.Experimental results show that the WC particles in the Fe-C liquid alloy migratedtowards the outer flank to form functionally gradient thick-walled casting compositesring under the centrifugal casting conditions, where the volume fraction of WCp in theouter region with a thickness of10~17mm reach70vol.%, and WC_Pwere distributeduniformity in the matrix. The hardness value of composite layer is up to HRA83andthe impact toughness is up to3.2J/cm~2; in the inner region,the hardness value is up toHRA72, the impact touhness is up to6J/cm~2.Microscopic observation showed that WC_Pin the composite layer of recycledcomposite ring were polyhedral, and were evenly distributed in the Fe-C matrix, thecore matrix of the recycled composite is consisting of acicular bainites, short rods andweb carbides, bits of WC_Pand ball and flake graphite.Dry sliding friction and wear tests with high speed shows that under different loadcondition, friction coefficient of recycled composite layers is slowly down and wearrate gradually increases with the increase of wear speed; the friction coefficient ofrecycled composite matrixs presents dropping trend and wear rate increases with theincrease of wear speed. Under different wear speed condtion, with the loadincreased,friction coefficient of recycled composite layers shows decrease trend, wearrate of recycled composite layers rises slowly and the change of curve gradient is verytiny;the friction coefficient of matrix layers shows floting phenomenom with the increase of load,wear rate gradually increases when the load is less than150N,andwhen more than150N,the wear rate repidly increases.Under the same experimental condtion, it is known that the wear-resistant ofregeneration composite materials is lower than hard alloy and WC_P/Fe-C compositematerials, but much higher than that of high-speed steel; wear-resistant of the corematrix layers is higher than that of high Cr cast iron and WC_P/Fe composite matrixlayers.this dicates that the recycled composite materials have good wear-resistant.Research of wear mechanism states that wear mechanisms of recycled compositesmatrix are plastic deformation and plowing wear slightly under relatively low load,And when the load is higher, the wear mechanisms are mainly adhesive wear、abrasive wear and oxidative wear; Wear mechanisms of recycled composite layers aremainly plowing wear and plastic formation in low speed condition, and with the highspeed, wear mechanisms are mainly abrasive wear, Adhesion wear and oxidative wear.