Study on Additive Manufacturing Optimization of High Hardness Material (AISI M4) Based on Preheating Process Using High Energy Directed Energy Deposition (DED) Technology

This study investigated the optimization of additive manufacturing for high-hardness material (AISI M4) via preheating processes using Direct Energy Deposition (DED) technology. AISI M4 metal powder is a high-speed tool steel that is extensively employed in steel rollers and molds due to its exceptional wear and impact resistance The service life of products can be extended by depositing high-hardness materials such as AISI M4 onto their surfaces through the employing of 3D printing technology. Nevertheless, previous study has demonstrated that residual stresses can generate surface defects, including cracks, as a result of discrepancies in cooling rates during the deposition process of dissimilar materials. A preheating method was implemented to alleviate residual stresses during the deposition process in order to resolve the problem. The preheating temperature, laser power, and feed rate were the process parameters that were established in this study. The experiments were conducted at room temperature, 200°C, and 300°C. Deposition of a 40×20 mm size was demonstrated. In order to assess the deposition efficiency of the high-hardness material, the presence of defects (such as cracks) in the deposition cross-section and the deposition height was analyzed.