Effect of auxiliary heating process on low power pulsed laser wire feeding deposition

Abstract

Low-power pulsed laser wire-feeding deposition has the advantages of low cost and less accumulation of heat. At the same time, the low laser power leads to the prominent problem of unfused defects in the deposited samples and the appearance of cold crack defects. In this study, a combined heating additive manufacturing process method combining the substrate induction heating and hot wire processes is proposed for this problem, and the corresponding experimental device is developed. Through an experiment on the influence of the auxiliary heating process on the deposition of pulsed laser wire feeding, the focus is on the improvement effect of the combined heating process on the deposition of low-power pulsed laser wire feeding. By comparing the processing experiments of thin-walled wall samples under different auxiliary heating process conditions, the influence of auxiliary heating process parameters on the geometry, microstructure, microhardness, and defects of the sample is revealed. The experimental process data and metallographic analysis results of the sample show that the combined heating process not only improves the energy input in the deposition process, but also reduces the temperature gradient between the deposited sample and the substrate, improves the laser absorption rate of the substrate, increases the size of the deposition channel and molten pool, reduces the surface roughness of the sample, and enhances the interlayer remelting, A more uniform macro shape contour is obtained. The open partial melting defect is effectively restrained, the porosity of the deposited sample is reduced, and crack defects are eliminated.

Keywords

• Pulsed laser wire deposition
• Auxiliary heating
• Combined heating
• Microstructure
• Unfused defects