Effect of B4C Addition on Microstructure and Wear Resistance of Laser Cladding NiCrBSi Coatings

In order to solve the problems of low hardness and poor wear resistance of titanium alloy, laser cladding technology was used to prepare NiCrBSi coatings with different amounts of B4C on the surface of Ti-6Al-4V alloy. The effects of B4C content on the microstructure evolution, hardness, fracture toughness, and wear resistance of NiCrBSi coatings were investigated. The results showed that with an increase of B4C addition, the size and number of ceramic phases TiB2, TiC, and CrB in the coating increased, and the ceramic phases were dispersed in the coating. The average microhardness of the coating with 9 wt.% B4C addition was the highest, reaching 1250.3 HV0.2, which is 15% higher than that of the coating without B4C addition. After adding B4C, the fracture toughness of the coating increased. When the addition of B4C was 3 wt.%, the fracture toughness of the coating was the highest, reaching 1.42 MPa m1/2, which is 178.4% higher than that of the coating without B4C. With the increase of the addition of B4C, the wear loss of the coating decreased and the wear resistance increased.