Effect of magnetic field assisted thermal diffusion on microstructure and properties of titanium alloy laser cladding coating

Ti–Al composite coating was prepared on the surface of a titanium alloy by the laser cladding technology and coaxial powder feeding under argon protection. The cladding material was AlSi10Mg aluminum alloy powder. The intermediate sample was thermally diffused at high temperature for 6 h and then placed in a certain intensity of the alternating electromagnetic field until completely cooled. The alloy substrate and coating solidified under the action of the alternating electromagnetic field, and the surface coating of a high strength titanium alloy was obtained. The morphology and microstructure of the composite coating were analyzed by SEM, XRD, and energy dispersive spectroscopy (EDS), and the hardness of the coating was measured. The results showed that the high temperature thermal diffusion promoted the interatomic diffusion; repaired some defects, such as cracks and pores; and eliminated the elemental metals that did not participate in the reaction, and the surface hardness of the coating joint reached the maximum. The electromagnetic stirring makes the titanium alloy coating and substrate bond well, the joint is relatively straight, the number of cracks and pores is obviously reduced, and the comprehensive performance of the coating is improved.