Understanding the thermal process during laser assisted ultra-high frequency induction deposition with wire feeding

Abstract

This study proposes a novel metal deposition method referred to as laser assisted ultra-high frequency induction (UHF) deposition. In this method, the UHF induction heat is used as the main heat source to melt the deposited metal, and the laser heat acts as an auxiliary heat source that provides a high-temperature substrate surface for efficient fusion between the deposited metal and substrate. A numerical model coupled with electromagnetic and temperature fields is developed to understand the thermal process of laser assisted UHF induction deposition. The thermal process with different combination states of the two heat sources is numerically investigated to reveal the influence mechanism of the two heat sources on the penetration depth of the deposited layer. Results show that the UHF induction heat increases the penetration depth of the deposited layer by raising the temperature of the deposited metal, and laser heat leads to an increment in penetration depth by providing a high substrate surface temperature. Decreasing the distance between the laser beam and metal wire also increases the substrate surface temperature, thereby increasing the penetration depth. Criteria for characteristic temperatures Tpeak1, Tpeak2, and Tinterval are proposed based on thermal process analysis to control thermal process and prevent the deposited layer from having a large penetration depth. Deposition experiments reveal the process feasibility of the proposed deposition method and validate the numerical model. The performance evaluation of the deposited layers proves that controlling the thermal process is the key for ensuring the performance of the deposited layer. The numerical model and criteria for characteristic temperatures provide an efficient way for controlling the thermal process during deposition; thus, reasonable performance of the deposited layer can be ensured.