Structure and wear resistance of Ti-TiC-TiB layers obtained by non-vacuum electron beam cladding

Department of Materials Science in Mechanical Engineering, Novosibirsk State Technical University, 630073, K. Marks av., 20, Novosibirsk, Russia

^* Corresponding author: lenivtseva_olga@mail.ru

Abstract

In this study structure and tribotechnical properties of cp-titanium after non-vacuum electron beam cladding of powder mixture containing boron carbide were investigated. Structural investigations were carried out using optical and scanning electron microscopy and X-ray analysis. The thickness of cladded layers was 1.3…2.5 mm. The beam moving speed was not influence the phase composition of coatings. The main phases of the surface layers were α- titanium (α′.- titanium), titanium carbide TiC and titanium boride TiB. It was determined that the average value of microhardness of the samples formed with the speed 25 mm/s was three times higher in comparison with substrate metal. A decrease in the beam moving speed led to an increase in the heat input per unit area and was accompanied by a reduction in the coating microhardness. To evaluate the wear resistance, friction test of the obtained materials against fixed abrasive particles was performed. The maximum relative wear resistance was exhibited by the coatings after cladding of 20 wt. % boron carbide and 30 wt. % titanium with the beam moving speed of 25 mm/s. Their wear resistance was 1.53 times higher as compared to cp-titanium.