Influence of the Relative Position of Powder–Gas Jet and Laser Beam on the Surface Properties of Inconel 625 Coatings Produced by Extreme High-Speed Laser Material Deposition (EHLA)

Abstract

Laser material deposition (LMD) is a widely used coating process in industry. However, to increase its economic appeal, higher process speeds are required. The solution to this challenge is an innovative modification known as extreme high-speed laser material deposition (EHLA). EHLA allows for an impressive increase in process speed from 2 m/min for conventional LMD to 500 m/min. With the ability to adjust process parameters, EHLA can generate tailor-made surface properties, expanding its potential application beyond current industrial uses. In this novel study, we explore the effects of relative positioning between tools (laser beam and powder–gas jet) and substrate on the surface properties of EHLA coatings. By laterally and axially offsetting the tools, the proportional energy coupling of the laser radiation into the powder–gas jet and substrate can be modified. Altering the position of the powder–gas jet can also affect the weld pool flow or number of particle attachments, thereby affecting surface properties. This approach allows for the adjustment of surface roughness over a wide range—from smooth, quasi-laser-polished surfaces to rough surfaces covered with particle adhesions.

Prediction Method for High-Speed Laser Cladding Coating Quality Based on Random Forest and AdaBoost Regression Analysis

“…According to the existing research, laser power (P), scanning speed (Ss), overlap ratio (Or) and powder feed ing rate (Vp) are the most important process parameters that affect the quality of the clad ding layer, so only these four parameters need to be changed in the experimental design For regression models, the more experimental results can be referred to during training, the better the fitting effect of the model, but the higher the complexity of the experiment. There fore, L25(5 6 ) experiments were designed in this study based on the Taguchi orthogonal, and the statistical results were taken as training sets for the RF model and AB model.…”

“…The smaller the values of MAE and RMSE, the higher the accuracy of the model. The calculation methods of MAE and RMSE are shown in Equations ( 5) and (6). The comparative verification results are illustrated in Figure 9.…”

“…As a new generation of processing technology, its working principle and heat transfer mode are very different from traditional cladding technology. Owing to the shielding effect of the powder material on the laser energy and the two-stage melting process before/after entering the melt pool, the substrate has a low heat input, the coating dilution ratio is smaller than 1/4 of traditional cladding, and the surface roughness is reduced to less than 1/10 of traditional cladding [ 6 ]. Additionally, it has a 100–250 times higher cladding speed than the traditional cladding, which leads to the fine grain of the coating, thus allowing for the improvement of all aspects of the coating performance [ 7 , 8 ].…”

Engineering Process Optimization and Quality Stability Control of High-Speed Laser Cladding Coatings Based on AHP-FCE

“…It is widely used to repair and protect oil drill parts to overcome the low efficiency of traditional laser cladding repair [3,4]. With the rapid increase of laser beam scanning speed, the high overlap between paths and the two-stage melting process before and after powder material enters the molten pool are common in high-speed laser cladding coatings [5][6][7]. As a result, the coating quality, including its forming quality, near-surface microstructure, and surface properties, is significantly different from those produced using traditional laser cladding [8][9][10].…”