TY - JOUR
T1 - Post-spray modification of cold-sprayed Ni-Ti coatings by high-temperature vacuum annealing and friction stir processing
AU - Huang, C. J.
AU - Yan, X. C.
AU - Li, W. Y.
AU - Wang, W. B.
AU - Verdy, C.
AU - Planche, M. P.
AU - Liao, H. L.
AU - Montavon, G.
N1 - Publisher Copyright:
© 2018
PY - 2018/9/1
Y1 - 2018/9/1
N2 - In this study, two post-spray treatments, i.e. high-temperature vacuum annealing (HTVA) and friction stir processing (FSP), were employed to modify the cold-sprayed (CS) Ni-Ti coatings, obtained from a mechanically blended powder. The phase transformation occurred at different HTVA temperatures, but with the formation of pores due to the Kirkendall effect. FSP proved to provide a new opportunity for the formation of intermetallic phases in the CSed Ni-Ti coating. A comparison of the microstructures, microhardness and tribological behaviors between the CSed and FSPed coatings, reveals that the microstructure of the modified Ni-Ti coating exhibits a mechanically alloyed layer with the in-situ synthesized Ni-Ti intermetallics, and no obvious defects are found. The microhardness of the improved layer is increased to 1003.5 ± 65.9 HV 0.1 , which is about 4.5 times compared to the CSed coating (222.5 ± 6.6 HV 0.1 ). In addition, the mechanically alloyed layer by FSP contains multiplicate Ni-Ti intermetallic compounds, exhibiting better wear resistance than that of the CSed coating, thus proving the effectiveness of FSP on the microstructural modification and properties improvement for the CSed metal-metal composite coatings.
AB - In this study, two post-spray treatments, i.e. high-temperature vacuum annealing (HTVA) and friction stir processing (FSP), were employed to modify the cold-sprayed (CS) Ni-Ti coatings, obtained from a mechanically blended powder. The phase transformation occurred at different HTVA temperatures, but with the formation of pores due to the Kirkendall effect. FSP proved to provide a new opportunity for the formation of intermetallic phases in the CSed Ni-Ti coating. A comparison of the microstructures, microhardness and tribological behaviors between the CSed and FSPed coatings, reveals that the microstructure of the modified Ni-Ti coating exhibits a mechanically alloyed layer with the in-situ synthesized Ni-Ti intermetallics, and no obvious defects are found. The microhardness of the improved layer is increased to 1003.5 ± 65.9 HV 0.1 , which is about 4.5 times compared to the CSed coating (222.5 ± 6.6 HV 0.1 ). In addition, the mechanically alloyed layer by FSP contains multiplicate Ni-Ti intermetallic compounds, exhibiting better wear resistance than that of the CSed coating, thus proving the effectiveness of FSP on the microstructural modification and properties improvement for the CSed metal-metal composite coatings.
KW - Cold spraying
KW - Friction stir processing
KW - High-temperature vacuum annealing
KW - Microstructure and property
KW - Ni-Ti composite coating
UR - http://www.scopus.com/inward/record.url?scp=85046422281&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2018.04.257
DO - 10.1016/j.apsusc.2018.04.257
M3 - 文章
AN - SCOPUS:85046422281
SN - 0169-4332
VL - 451
SP - 56
EP - 66
JO - Applied Surface Science
JF - Applied Surface Science
ER -