This work was aimed at developing a route for the deposition of TiB_2-Ni cermet coating. The feedstock was firstly prepared by agglomerate and sintering, which was subsequently subjected to plasma spraying. The microstructures and the phase composition of the powders, as well as the sprayed coatings were analyzed by SEM and XRD. The micro hardness (Hv) and fracture toughness (K_(IC)) of the coatings were evaluated. Sliding wear tests were also performed on the sprayed coating by SRV tester using GCr15 as a counterpart. The result showed that all the TiB_2-Ni coatings consisted of TiB_2, Ni and Ni_(20)Ti_3B_6 phase, whose amount varied depending on the powder calcination temperature and the TiB_2 content in the powder. Both the hardness and the fracture toughness changed correspondingly. The brittle Ni_(20)Ti_3B_6 phase was the main factor to reduce the fracture toughness of the coatings, which also induced detrimental effect on the slide wear properties. The 60TiB_2-40Ni coating deposited from powder calcined at 1300°C presented better sliding wear performance as it had less amount of Ni_(20)Ti_3B_6 phase and higher amount of TiB_2 was retained in the coating.
展开▼
