Influence of Laser Boriding on the Friction and Wear of Sliding Couples With Bearing Alloys

Abstract

The present study discusses the influence of laser borided surface layer on the parameters of sliding couples lubricated by engine oil. The borided layer was created by laser remelting of a surface layer of steel samples coated with amorphous boron. The study of friction, wear, and lubrication was conducted on the pairs made of steel AISI 5045 and SAE-783 and SAE-48 bearing alloys which were lubricated with 15W/40 engine oil. The research showed important differences in the friction coefficient and temperature in the tested couple with laser borided surface layer. In the couples containing the counterparts with SAE-783 bearing alloy, the tested parameter of friction was higher than in the couple composed of counterparts with SAE-48 bearing alloy. The counterparts with SAE-48 showed more intensive wear in contact with the laser borided surface layer than the counterpart with SAE 783. The process of friction at the contact area of the sliding couple with laser borided surface layer leads to the destruction of the lubricating properties of 15W/40 engine oil and reduces its resistance to scuffing and seizure.

Experimental Analysis of Tribological Processes in Friction Pairs with Laser Borided Elements Lubricated with Engine Oils

“…The observation of the course of the friction coefficient shows that low unit pressures influence the shaping of favorable lubrication conditions, and the system changes the existing geometric structures of both elements into a composition ensuring the most favorable cooperation conditions. The resulting structure provides the given pair with optimal functionality, caused by the creation of stable operational surface layers on both elements of the friction pair [ 35 , 36 ].…”

“…Also, an increase in roughness of the harder material results in an increase in the wear particles detached from the softer material [ 33 ]. The hard wear products created in the friction process induce chipping, slicing and grinding, which intensify the wear process [ 36 , 39 ].…”

Mechanical and tribological behaviour of titanium boride coatings processed by thermochemicals treatments

“…This technique allows to develop a hard boride layer, on the titanium surface, by the diffusion of boron atoms in the substrate [8,9]. This film is generated at a temperature in the range of 700–1100°C by several methods, including electrochemical boriding [10], laser boriding [11], boriding in fluidized bed reactor [12], boriding by electro-beam evaporation [13], plasma-assisted boriding [14], pack boriding [15] and boriding in molten salts [16].…”