Microstructure and Properties of Laser Cladding Coating on the Surface of Superalloy Ti600

Abstract

The laser cladding technology was used to prepare the Ti / TiB₂ composite coating on the surface of Ti600, and the microstructure and performance test results of the coating obtained under different laser specific energy conditions were analyzed. Studies have shown that the laser cladding coating and the substrate have achieved a good bond, and TiB₂ has formed into cellular TiB₂ after melting, and further solid solution becomes a whisker structure. The diffused TiC and TiN nuclei in the middle of the coating were fully grown and developed a dense dendrite structure with TiB₂ particles. A dual-phase structure of granular TiB₂ and many lamellar structures was formed under the coating. When the laser specific energy is 20 kJ / cm², the coating reaches the highest microhardness of 990HV, nearly 2.5 times the hardness of the substrate. The amount of wear shows a monotonic decrease with the increase of the specific energy of the laser, and the average friction coefficient shows a monotonous decrease as the specific energy of the laser increases.