Three-dimensional numerical simulation of temperature field evolution in laser cladding CoCrFeNi high-entropy alloy process

Abstract

There have been many studies on the forming process of CoCrFeNi high-entropy alloy by laser additive manufacturing, but there is a lack of systematic research on the numerical simulation of the forming process. This paper establishes a three-dimensional transient model of laser additive manufacturing high-entropy alloy by combining numerical simulation with experiment. The temperature field distribution of laser additive manufacturing CoCrFeNi high-entropy alloy on 316L substrate is simulated. The temperature distribution cloud diagram is obtained under different laser process parameters and the temperature change curve at the same node. The mechanism of surface spheroidization, pore, and metallurgical defect formation is revealed, and the experimental verification is realized. Finally, the forming process of laser cladding CoCrFeNi high entropy alloy block was explored. The results show that the maximum temperature of the cladding layer can reach more than 5000 °C during the cladding process. When other conditions remain unchanged, when the laser power increases from 1000 W to 1400 W, the temperature at the junction increases from 1588.63 °C to 2238.64 °C. At the same time, due to the insufficient melting of metal powder and the impact of powder on the molten pool, the surface of the additive is powdered and spheroidized. In addition, low laser power and low scanning speed will cause metallurgical defects between the cladding and the substrate.