Microstructure and mechanical properties of TiC/FeCrSiB coating by laser additive remanufacturing on shearer spiral blade

Abstract

Spiral blades are the main working mechanism of shearers, and the service life of blades directly affects the coal-rock cutting progress and enterprise production efficiency. To repair the damaged spiral blade and improve the wear resistance, FeCrSiB coatings having different amounts of reinforcing TiC particles were fabricated on the blade material 34CrNiMo6 by laser additive manufacturing technology. The effects of the TiC particle weight fraction on the microstructure, phase, hardness and wear resistance of the TiC/FeCrSiB composite coating were systematically studied. A laser additive remanufacturing repair experiment of damaged spiral blades based on reverse engineering technology was performed. The results indicated that the composite coating had good metallurgical bonding with the 34CrNiMo6 substrate, and the TiC particles converged towards the top of the coating via Marangoni convection and dynamic viscosity. The composite coatings mainly consisted of γ-(Fe, Cr) solid solution, M 23 C 6 , Fe 2 B/Cr 2 B and TiC. By increasing the TiC concentration in the composites, the hardness and wear resistance of the coating were significantly improved. The Rockwell hardness, microhardness and wear rate of the 30%-TiC-reinforced coating were 74.82 HRC, 1143.61 HV 0.5 and 0.45 × 10 −2 mm 3 N −1 mm −1 , respectively, and the wear resistance of the composite coating was 9 times higher than that of the substrate. The experimental results show that the laser additive remanufacturing TiC reinforced coating was an effective method to repair damaged spiral blades and improve the service performance. • The TiC/FeCrSiB ceramic composite reinforced coating was fabricated. • The TiC tend to converged towards the top of coating via Marangoni convection and dynamic viscosity. • The wear resistance of composite coatings is 9 times higher than that of blade material.