Fabrication of gradient structure for enhancing wear resistance of GCr15 bearing steel friction shim

The wear resistance of metallic shims under heavy load is crucial for the friction behavior of friction damper in civil engineering. This study verifies the potential of the strengthening grinding process (SGP) to enhance the wear resistance of metallic materials under heavy load. A multidisciplinary effort is shown in this paper to investigate the wear mechanism of SGP-treated GCr15 bearing steel in terms of the application scenario of civil engineering. The SGP treatment uses a multiphase abrasive comprising steel balls, corundum powder, and strengthening liquid to impact the surface of the GCr15 bearing steel. Then, a dry friction sliding test was performed on the polished, sandblasted, and SGP-treated GCr15 bearing steel. The microtopography and microstructure of these three friction shims with different treatments before and after the wear test were compared and analysed. The test results indicated the feasibility of SGP in enhancing the wear resistance of GCr15 bearing steel friction shims under heavy loads in terms of the application scenario of civil engineering. The SGP-treated sample had a more stable friction coefficient (0.475) and slighter wear compared to the other two samples due to its enhanced layer with a gradient structure and a thickness of approximately 23 μm.