Microstructure, Microhardness, Corrosion and Wear Resistance of B, Si and B-Si Coatings Produced on C45 Steel Using Laser Processing

Abstract

The paper presents the results of the microstructure investigation, phase and chemical composition, microhardness as well as corrosion and wear resistance tests of B-Si coatings produced on C45 steel. In this study, boron and silicon were added to the surface of steel using the laser alloying process. The main purpose of the study was to check whether the use of silicon, boron or a mixture of these chemical elements would improve the mechanical properties of the surface. Boron and silicon, as well as its mixture, were prepared in various proportions and subsequently were applied on steel substrate in the form of pre-coat (paste) of 80 µm thick. All pre-coats were processed by a laser beam and the obtained microstructures were analyzed and compared. Laser alloying processes were carried out using device equipped with a CO2 laser. After laser alloying, the microstructure consisted of a melted zone, heat affected zone and unchanged steel substrate. The newly created B-Si coatings were characterized by properties better than the case of boron and silicon coatings, with particularly high microhardness in the range from 1430 HV to 1870 HV, as well as high corrosion and wear resistance.