Direct Laser Growth of Inсonel 625/TiC Composite: Effect of Structural State of Initial Powder

Abstract

This work investigates the influence of structural state of the initial powders of composite material Inconel 625/TiC on the tendency to crack formation in the process of direct laser-assisted growth. It has been shown that the preliminary mixing of powders in a planetary ball mill, in contrast to their separate supply or mixing of powders in a gravitational mixer, makes it possible to avoid the formation of cracks in the synthesized object. It has been established that in the process of mixing of powders in a ball mill, a layer of titanium carbide is formed on the surface of the Inconel particles, and the carbide phase is subjected to mechanoalloying by the elements of the matrix. The change in the structural state of the powder leads to a change in its thermophysical properties, which has an effect on the crystallization processes. At the laser power P = 400–800 W, the carbide phase is not melted in the composite materials obtained from powders mixed using a ball mill, whereas when using a separate powder supply and upon their mixing in the gravitational mixer, the TiC phase undergoes recrystallization.