Cold deformation treatment of Cu-bearing stainless steel through a cold rolling process combined with electric pulse treatment(EPT)can significantly improve the microstructure and formability of cold-rolled Cu-bearing...Cold deformation treatment of Cu-bearing stainless steel through a cold rolling process combined with electric pulse treatment(EPT)can significantly improve the microstructure and formability of cold-rolled Cu-bearing stainless steel.The microstructure after EPT was characterized by scanning electron microscopy,transmission electron microscopy,and in-situ tensile testing.It is found that compared with conventional heat treatment,EPT process can significantly promote the nucleation rate and mobility at grain boundaries of the deformed samples,greatly accelerating the recovery and static recrystallization of Cu-bearing stainless steel samples at lower temperatures and contributing to the recovery of anisotropy and the re-molding of deformed samples.Microstructural characterization and theoretical analyses show that the rapid recrystallization during EPT process is caused not only by Joule heating effects but also by non-thermal effects that accelerate grain boundary migration and dislocation destruction and regeneration.In addition,EPT process significantly accelerated the nucleation and precipitation growth of Cu-rich phase.The coarsening of Cu-rich phase during EPT process is due to not only the high vacancy diffusion coefficient under the action of the electric pulse but also the increase in the vacancy diffusion flux induced by the electromigration in the process of the electric pulse.展开更多
Incorporating ceramic particles into metal matrices is a proven strategy for boosting mechanical properties and wear resistance.The reinforcement potential of tungsten carbide(WC)particles in 316L stainless steel is r...Incorporating ceramic particles into metal matrices is a proven strategy for boosting mechanical properties and wear resistance.The reinforcement potential of tungsten carbide(WC)particles in 316L stainless steel is revealed,utilizing selective laser melting(SLM)to fabricate composites with 5 and 10 vol.%WC.The WC incorporation markedly alters the composite’s microstructure and mechanical attributes.Notably,5 vol.%WC-316L composite exhibits a refined submicron cellular structure,averaging 0.67μm in grain size.Elemental diffusion at WC-316L interface formed a 0.8μm gradient transition layer enriched with M_(2)C carbides(Fe,Cr,W),ensuring robust metallurgical bonding.Compared with unreinforced 316L,5%WC composite exhibits a 70%increase in tensile strength,reaching 1012.6 MPa,and a 25.3%rise in hardness,while maintaining acceptable ductility.10%WC composite achieves a 70.8%hardness enhancement,albeit with reduced elongation.Friction coefficient is reduced by up to 17.3%,and the wear mechanism shifts from adhesive to abrasive,significantly improving wear resistance.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52305401 and 52475391)National Key Research and Development Program of China(2024YFB3714301)+1 种基金the Fundamental Research Program of Shanxi Province(202303011211004,TZLH20230818001)Engineering Research Center of the Ministry of Education.
文摘Cold deformation treatment of Cu-bearing stainless steel through a cold rolling process combined with electric pulse treatment(EPT)can significantly improve the microstructure and formability of cold-rolled Cu-bearing stainless steel.The microstructure after EPT was characterized by scanning electron microscopy,transmission electron microscopy,and in-situ tensile testing.It is found that compared with conventional heat treatment,EPT process can significantly promote the nucleation rate and mobility at grain boundaries of the deformed samples,greatly accelerating the recovery and static recrystallization of Cu-bearing stainless steel samples at lower temperatures and contributing to the recovery of anisotropy and the re-molding of deformed samples.Microstructural characterization and theoretical analyses show that the rapid recrystallization during EPT process is caused not only by Joule heating effects but also by non-thermal effects that accelerate grain boundary migration and dislocation destruction and regeneration.In addition,EPT process significantly accelerated the nucleation and precipitation growth of Cu-rich phase.The coarsening of Cu-rich phase during EPT process is due to not only the high vacancy diffusion coefficient under the action of the electric pulse but also the increase in the vacancy diffusion flux induced by the electromigration in the process of the electric pulse.
基金supported by Opening funding of National Key Laboratory of Aerospace Liquid Propulsion(HTKJ2024KL011004)Aeronautical Science Fund of China(ASFC-20240042070001)+2 种基金Opening funding of State Key Laboratory of Metal Forming Technology and Heavy Equipment(B2408100.W05)National Key R&D Program of China(2022YFB4601804)National Natural Science Foundation of China(52250287,52275375).
文摘Incorporating ceramic particles into metal matrices is a proven strategy for boosting mechanical properties and wear resistance.The reinforcement potential of tungsten carbide(WC)particles in 316L stainless steel is revealed,utilizing selective laser melting(SLM)to fabricate composites with 5 and 10 vol.%WC.The WC incorporation markedly alters the composite’s microstructure and mechanical attributes.Notably,5 vol.%WC-316L composite exhibits a refined submicron cellular structure,averaging 0.67μm in grain size.Elemental diffusion at WC-316L interface formed a 0.8μm gradient transition layer enriched with M_(2)C carbides(Fe,Cr,W),ensuring robust metallurgical bonding.Compared with unreinforced 316L,5%WC composite exhibits a 70%increase in tensile strength,reaching 1012.6 MPa,and a 25.3%rise in hardness,while maintaining acceptable ductility.10%WC composite achieves a 70.8%hardness enhancement,albeit with reduced elongation.Friction coefficient is reduced by up to 17.3%,and the wear mechanism shifts from adhesive to abrasive,significantly improving wear resistance.
