Friction and wear properties of TiC_p/Ni-based laser clad layer on TC4 alloy

The friction and wear properties of TC4 alloy and TiC_p/Ni-based laser clad layer thereon under dry sliding against a hard-alloy (YG8B) in atmosphere and vacuum were comparatively investigated on a YTN TB-100 type pin-on-disc friction and wear tester. The microstructure of the laser-clad layer was analyzed on a transmittance electron microscope, the morphologies of the worn surfaces of the TC4 alloy and TiC_p/Ni-based laser clad layer and of the corresponding counterpart hard-alloy were observed on a scanning electron microscope. It was found that the environmental pressure had great effects on the friction and wear properties of the materials alloy and the laser-clad layer. Namely, both the TC4 alloy and TiC_p/Ni-based laser clad layer registered larger friction coefficients in vacuum than in atmosphere, which could be attributed to the enhanced adhesion in vacuum. The TC4 alloy had a larger wear rate in atmosphere than in the vacuum, while the TiC_p/Ni-based laser clad layer is characterized by abrasive wear in atmosphere and by a combination of abrasive wear and adhesion wear in vacuum.