Cailiao gongcheng (Mar 2017)
Tribological Behavior of Multi-layered WC-Co/MoS<sub>2</sub>-Ni Self-lubricating Coating Fabricated by Detonation Gun Spraying
Abstract
The multilayered composite WC-Co/MoS2-Ni self-lubricating coatings were prepared by detonation gun spraying technology. The coating microstructure, element distribution, adhesive strength, and tribological properties were studied systematically. The results show that a little of MoS2 is oxidized and decomposed into gas of SO2 during the high-temperature spraying process. The SO2 left in the coating and can form into the micro porosities. The friction coefficient of the WC-Co coating first increases rapidly in the initial running-in phase, and then gradually increases slightly after entering into the steady-state phase; whereas the friction coefficient of multilayer composite coating steps in the steady-state phase soon and starts to decline gradually when the top WC-Co coating became perforated. By comparison, the coating cohesion declines slightly after adding the self-lubricating layer MoS2-Ni, but the friction coefficient decreases by about 40%, and the wear resistance is also improved slightly.
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