Wear behavior of self-lubricating boride layers produced on Inconel 600-alloy by laser alloying

Abstract

In this work, laser alloying has been used in order to produce the self-lubricating boride layers on Inconel 600-alloy. The two-step process was used during laser alloying. First, the surface of the substrate material was coated with a paste containing amorphous boron and calcium fluoride CaF2 as a self-lubricating addition. Then, this surface was re-melted by laser beam using TRUMPF 2600 Turbo CO2 laser. The laser beam powers 1.56 kW and 1.95 kW were used for laser alloying. The re-melted zone included dendritic and globular precipitates of nickel, chromium and iron borides among the soft Ni-phase as well as CaF2 particles, locating close to the surface. The microhardness of the re-melted zone, containing solid lubricant, was lower than that of the laser-alloyed layer with only boron. Whereas the wear resistance was higher. The tribofilm was observed on the worn surfaces of laser-alloyed layers with boron and CaF2. The presence of the tribofilm reduced wear of mating parts and improved their tribological properties.