Session: 03-08-01: Computational Modeling and Simulation for Advanced Manufacturing

Paper Number: 139609

139609 - Study on Thermal Behavior and Microstructure Evolution of the Stainless Steel 316l Surface Coating by Direct Diode Laser Cladding With Hot-Wire Feeding 

Hot-wire cladding technique assisted with a high-power direct diode laser has been recognized as a cost-effective technique for the repair or fabrication of critical components and tools in industries such as automotive, aerospace, nuclear, and defense. This study aims to enhance the understanding of the laser hot-wire cladding process by examining the relationship between thermal cycles, accompanying phase transformations, and the mechanical properties of the deposited layers. A three-dimensional (3-D) thermal finite element (FE) model was developed to simulate the temperature field evolution during the stainless steel 316L cladding process. The accuracy of this model was experimentally validated through temperature evolution curves obtained by thermocouples placed at the substrate surface near the clad zone. The experimentally supported FE thermal model was further integrated with thermo-kinetic equations to predict the microhardness of the clad layers based on specific cooling rates. Additionally, the microstructure characteristics observed across the cross-sections of the clad zone were analyzed under different laser powers and scanning speeds. These were then associated with the respective thermal cycles and microhardness measurements. The results showed that variances in cooling rates from the top to the bottom of the clad layer significantly affected the acquired microstructure and microhardness distribution. Notably, reasonable adjustments in laser power and scanning speed were observed to critically affect the cooling rate of the clad layer and further enhance the microhardness distribution of the clad zone. A good agreement between the numerical predictions and experimental results revealed the effectiveness of the proposed model in predicting the microhardness distribution and microstructural characteristics of the obtained clad layers.

Presenting Author: Wei Tong Southern Methodist University

Presenting Author Biography: Wei Tong is currently a full Professor in the Department of Mechanical Engineering at SMU. He had served as the Acting Director of the Research Center for Advanced Manufacturing (RCAM) from 2021-2023. His research interests are in solid mechanics, materials engineering, and manufacturing, including 1) metal plasticity with applications in metal forming simulations and other manufacturing processes, 2) ductile failure and fracture with applications in critical structural designs under impact loading, and 3) laser materials processing with applications in welding, cladding, and additive manufacturing.

Authors:

Mingpu Yao Southern Methodist University
Fanrong Kong ESAB Inc.
Wei Tong Southern Methodist University