Optimization of single-pass geometric characteristics of IN718 by fiber laser via linear regression and response surface methodology

Abstract

Direct laser deposition is among the critical processes for fabricating and reconstructing parts. This study investigated a single-pass laser coating of Inconel 718 superalloy powder on the same substrate using a continuous fiber laser. The linear regression method was used to establish the relationship between the main process parameters, including laser power (P), laser scanning speed (V), and powder feeding rate (F), as well as geometric characteristics of the single-pass cladding including width, height, dilution percentage, and single-pass wetting angle. In addition, drawing process maps by two methods of linear regression and the response surface method was investigated comprehensively. The results showed that the width of a single pass was directly related to the laser power and inversely related to the laser scanning speed. In addition, this parameter has a negligible association with the powder feeding rate. Furthermore, it was found that the height of a single pass has a direct and inverse relationship with the powder feeding rate and the laser scanning speed, respectively, but poorly correlated with the laser power. Dilution was directly and inversely related to laser scanning speed and powder feeding rate, respectively, while the trend was quite the opposite for the wetting angle.