To improve the corrosion resistance of friction stir welded(FSW)joints,in situ shot-peening-assisted cold spray coating was applied to the surface of FSW joints.The microstructure and corrosion behavior of the coating...To improve the corrosion resistance of friction stir welded(FSW)joints,in situ shot-peening-assisted cold spray coating was applied to the surface of FSW joints.The microstructure and corrosion behavior of the coatings were investigated.The results showed that a dense coating was obtained by cold spraying technology.Moreover,the use of in situ shot-peeningassisted technology significantly reduced the porosity of the coating,which has a positive impact on the microstructure and the mechanical performance.Exfoliation corrosion tests showed that the coating aff ected positively on the corrosion resistance.On the coated surface,the craters caused by shot-peening particles were corroded in the form of exfoliation corrosion,while the exposed particles were corroded in the form of intercrystalline corrosion.This work provides a new approach to the corrosion protection of FSW joints.展开更多
Influence of residual stress and surface morphology induced by shot-peening on fatigue behav- ior of a medium temperature tempered spring steel 60 Mn has been studied.The compressive residual stress induced in the nea...Influence of residual stress and surface morphology induced by shot-peening on fatigue behav- ior of a medium temperature tempered spring steel 60 Mn has been studied.The compressive residual stress induced in the near-surface region may improve fatigue limit from 930 to 1010 MPa,and the very high tensile residual stress in the interior may reduce it from 1010 to 940 MPa,whereas the severe surface damage may cause a drop-off of it from 1010 down to 800 MPa.Fatigue cracks initiated in such position where the equivalent Mises stress,including residual stress,exceeded the local strength of the material.The compressive residual stress, induced by shot-peening,may intensify the effect of crack closure,so as to decrease the crack growth rate.展开更多
In this paper, the sliding contact fatigue wear performance of shot-peened zirconia-silicon carbide composite (ZrO2/SiC) plates in contact with silicon nitride balls under compressive residual stress in dry conditions...In this paper, the sliding contact fatigue wear performance of shot-peened zirconia-silicon carbide composite (ZrO2/SiC) plates in contact with silicon nitride balls under compressive residual stress in dry conditions was investigated in order to improve the wear resistance of ZrO2/SiC friction parts. The wear resistance of ZrO2/SiC plates after shot peening was higher than that of plates not treated with shot peening in sliding wear testing under Hertziancontact. Due to fine Zirconia particle shot peening, the tetragonal phase crystal structure in ZrO2 in the near-surface of ZrO2/SiC plates was changed, and 1100 MPa compressive residual stress could be introduced into the near-surface layer of ZrO2/SiC plates. The compressive residual stress was determined to be the main factor in the improvement of the sliding wear resistance of ZrO2/SiC plates.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51774047)the Great Wall Scholars Program of Beijing(No.CIT&TCD20170309).
文摘To improve the corrosion resistance of friction stir welded(FSW)joints,in situ shot-peening-assisted cold spray coating was applied to the surface of FSW joints.The microstructure and corrosion behavior of the coatings were investigated.The results showed that a dense coating was obtained by cold spraying technology.Moreover,the use of in situ shot-peeningassisted technology significantly reduced the porosity of the coating,which has a positive impact on the microstructure and the mechanical performance.Exfoliation corrosion tests showed that the coating aff ected positively on the corrosion resistance.On the coated surface,the craters caused by shot-peening particles were corroded in the form of exfoliation corrosion,while the exposed particles were corroded in the form of intercrystalline corrosion.This work provides a new approach to the corrosion protection of FSW joints.
文摘Influence of residual stress and surface morphology induced by shot-peening on fatigue behav- ior of a medium temperature tempered spring steel 60 Mn has been studied.The compressive residual stress induced in the near-surface region may improve fatigue limit from 930 to 1010 MPa,and the very high tensile residual stress in the interior may reduce it from 1010 to 940 MPa,whereas the severe surface damage may cause a drop-off of it from 1010 down to 800 MPa.Fatigue cracks initiated in such position where the equivalent Mises stress,including residual stress,exceeded the local strength of the material.The compressive residual stress, induced by shot-peening,may intensify the effect of crack closure,so as to decrease the crack growth rate.
文摘In this paper, the sliding contact fatigue wear performance of shot-peened zirconia-silicon carbide composite (ZrO2/SiC) plates in contact with silicon nitride balls under compressive residual stress in dry conditions was investigated in order to improve the wear resistance of ZrO2/SiC friction parts. The wear resistance of ZrO2/SiC plates after shot peening was higher than that of plates not treated with shot peening in sliding wear testing under Hertziancontact. Due to fine Zirconia particle shot peening, the tetragonal phase crystal structure in ZrO2 in the near-surface of ZrO2/SiC plates was changed, and 1100 MPa compressive residual stress could be introduced into the near-surface layer of ZrO2/SiC plates. The compressive residual stress was determined to be the main factor in the improvement of the sliding wear resistance of ZrO2/SiC plates.
