Directed energy deposition process optimization and factor interaction analysis by response surface methodology

The purpose of this study is to optimize the critical parameters of the directed energy deposition (DED) process using the response surface methodology (RSM) and central composite design (CCD). The experiments investigate the influence of three key process factors, namely laser power, powder feed rate, and scanning speed, on deposition efficiency, deposition rate (DR), and porosity. Additionally, through analysis of variance (ANOVA), the significant factors and interaction effects are identified, and predictive models are developed for quality prediction. The research successfully optimizes the process parameters, which are validated through the fabrication of geometric components, specifically thin-walled nozzles. The study introduces innovative approaches such as “plunge-cutting toolpath” and “hybrid laser head lift height (Z-offset) method” to address the challenges associated with complex geometries. Additionally, the reliability and practicality of the optimized process parameters are confirmed.