During atmospheric plasma spraying,a cooling process usually plays an important role in the coating quality,especially for the oxidation containment of metallic coatings.CuNiIn and Mo coatings were prepared using atmo...During atmospheric plasma spraying,a cooling process usually plays an important role in the coating quality,especially for the oxidation containment of metallic coatings.CuNiIn and Mo coatings were prepared using atmospheric plasma spraying with different cooling processes.The obtained coatings were characterized in terms of microstructure,microhardness and tensile strengths.The relation between the coating microstructure and their fretting fatigue behavior was emphasized.The results show that the sensitivity of Mo coatings to the cooling process is lower than CuNiIn coatings.The resistance to fretting fatigue is determined by the coating microhardness,correlated with the contents of oxides and pores.The fretting wear mechanisms of both the coatings are galling,third body abrasive wear and material transfer.展开更多
Ion beam enhanced deposition (IBED) was employed to increase the fretting fatigue resistance of Ti6AI4V. CrN and TiN hard coatings were applied on the base material and shot peening was combined with the hard coatings...Ion beam enhanced deposition (IBED) was employed to increase the fretting fatigue resistance of Ti6AI4V. CrN and TiN hard coatings were applied on the base material and shot peening was combined with the hard coatings to study the duplex effect on fretting fatigue resistance. The IBED coatings exhibited a good bonding strength. They did not spall off even after shot peening. However, an optimum composition of CrN showed better fretting fatigue resistance than that of TiN with the same processing parameters.展开更多
The fretting wear behavior of plasma spraying CoCrW and Cr3C2-NiCr coatings were investigated. The results showed both plasma spraying coatings were inferior to K417 nickel superalloy in the fretting wear resistance. ...The fretting wear behavior of plasma spraying CoCrW and Cr3C2-NiCr coatings were investigated. The results showed both plasma spraying coatings were inferior to K417 nickel superalloy in the fretting wear resistance. The characterized fatigue delamination of the plasma sprayed coatings was evidently different from that of the homogeneous materials. The lamellar cohesion, oxide inclusions and porosity were critical factors that controlled the fretting wear resistance. In the view of contact mechanics, the fretting wear behavior of plasma spraying coatings was characterized.展开更多
The fretting characteristics of TiN coated Zircaloy-4 tube were investigated experimen-tally. The fretting experiment was performed using TIN coated Zircaloy-4 tube as the fuel rod clad-ding material and uncoated Zirc...The fretting characteristics of TiN coated Zircaloy-4 tube were investigated experimen-tally. The fretting experiment was performed using TIN coated Zircaloy-4 tube as the fuel rod clad-ding material and uncoated Zircaloy-4 tube as one of grids. TIN coating is probably one of the mostfrequently and successfully used PVD coatings for the mitigation of fretting. In this study, TiN coat-ing by PVD was employed for improvement of Zircaloy-4 tube fretting characteristics. The frettingtester was designed and manufactured for this experiment. The number of cycles, slip amplitudeand normal load were selected as main factors of fretting. The results of this research showed thatthe wear volume of TiN coated Zircaloy-4 tube increased as number of cycles, normal load andslip amplitude increase but the quantity of volume was lower than the case of uncoated Zircaloy-4tube pairs.展开更多
基金the National Natural Science Foundation of China[grant numbers 51875424,51501137 and 51702244]the Fundamental Research Funds for the Central Universities[WUT:2019III033].
文摘During atmospheric plasma spraying,a cooling process usually plays an important role in the coating quality,especially for the oxidation containment of metallic coatings.CuNiIn and Mo coatings were prepared using atmospheric plasma spraying with different cooling processes.The obtained coatings were characterized in terms of microstructure,microhardness and tensile strengths.The relation between the coating microstructure and their fretting fatigue behavior was emphasized.The results show that the sensitivity of Mo coatings to the cooling process is lower than CuNiIn coatings.The resistance to fretting fatigue is determined by the coating microhardness,correlated with the contents of oxides and pores.The fretting wear mechanisms of both the coatings are galling,third body abrasive wear and material transfer.
文摘Ion beam enhanced deposition (IBED) was employed to increase the fretting fatigue resistance of Ti6AI4V. CrN and TiN hard coatings were applied on the base material and shot peening was combined with the hard coatings to study the duplex effect on fretting fatigue resistance. The IBED coatings exhibited a good bonding strength. They did not spall off even after shot peening. However, an optimum composition of CrN showed better fretting fatigue resistance than that of TiN with the same processing parameters.
文摘The fretting wear behavior of plasma spraying CoCrW and Cr3C2-NiCr coatings were investigated. The results showed both plasma spraying coatings were inferior to K417 nickel superalloy in the fretting wear resistance. The characterized fatigue delamination of the plasma sprayed coatings was evidently different from that of the homogeneous materials. The lamellar cohesion, oxide inclusions and porosity were critical factors that controlled the fretting wear resistance. In the view of contact mechanics, the fretting wear behavior of plasma spraying coatings was characterized.
文摘The fretting characteristics of TiN coated Zircaloy-4 tube were investigated experimen-tally. The fretting experiment was performed using TIN coated Zircaloy-4 tube as the fuel rod clad-ding material and uncoated Zircaloy-4 tube as one of grids. TIN coating is probably one of the mostfrequently and successfully used PVD coatings for the mitigation of fretting. In this study, TiN coat-ing by PVD was employed for improvement of Zircaloy-4 tube fretting characteristics. The frettingtester was designed and manufactured for this experiment. The number of cycles, slip amplitudeand normal load were selected as main factors of fretting. The results of this research showed thatthe wear volume of TiN coated Zircaloy-4 tube increased as number of cycles, normal load andslip amplitude increase but the quantity of volume was lower than the case of uncoated Zircaloy-4tube pairs.
