Study on the impact of laser power variation on the performance of Ti-6Al-4 V coating by laser cladding on HT250.

• Laser cladding of TC4 coating on cast iron, no cracking, max hardness 480.9 HV. • Scan speed 13 mm/s, 500 W 1st layer, 600 W 2nd layer, eradicated ledeburite. • 600 W coating outperforms 800 W & 1000 W in wear resistance at RT & 500 ℃. To enhance the wear resistance of the HT250 surface and eliminate ledeburite formation at the coating-substrate interface, a dual-layer Ti-6Al-4 V coating was created on HT250 surfaces through laser cladding. The influence of varying laser power on the microstructure, hardness, and wear resistance was investigated. The results indicate that a laser power of 600 W for the second layer can eliminate the formation of ledeburite at the coating-substrate interface, fabricating a crack-free cladding layer with a maximum hardness of 480.9 HV. Needle-like TiC was in-situ synthesized in the surface zone when the laser power was set at 600 W and 800 W. The surface hardness at 600 W is 1.1 and 1.4 times higher than that at 800 W and 1000 W, respectively. The optimal wear resistance was achieved at a laser power of 600 W, exhibiting 0.52 and 0.40 times the wear rates compared to those at 800 W and 1000 W, respectively, at 500 °C. At temperatures below 300 °C, the predominant wear mechanisms for all three coatings were abrasive wear and a small amount of oxidative wear. As the temperature increased to 500 °C, oxidative wear became the primary wear mechanism for the coatings. [ABSTRACT FROM AUTHOR]