Abstract
Additive manufacturing (AM) also known as 3D printing, is considered to be an essential area of the Fourth Industrial Revolution (FIR), especially with the integration of such smart manufacturing processes and advanced information technologies. It is fast becoming a manufacturing technology of choice for the aerospace and medical industry due to its ability to print complex parts using difficult to machine materials. Together with doing cost feasibility studies, it is important to also look at research and development of metals that are suitable to produce parts using additive manufacturing. This study focused on comparing and correlating the impact of fabrication technique and alloy type on mechanical integrity and corrosion response. Two grades of stainless steel (304 and 410) were fabricated using DED and SLM techniques. The built specimens were then characterized using SEM, EDS to identify solidification patterns, defects, and phase distributions. The mechanical performance was assessed through Vickers microhardness, nanoindentation, and tribological testing. The test specimens were also subjected to electrochemical testing to evaluate their behavior using Open Circuit Potential, potentiodynamic polarization, and post-corrosion SEM-EDS inspection in various electrolytes (HCl, H₂SO₄, NaCl).
The comprehensive analysis of feedstock powders and additively manufactured stainless steel components demonstrates the significant influence of particle morphology, elemental distribution, and fabrication technique on resulting microstructural characteristics. The SEM evaluations revealed that DED and SLM processes produce distinct microstructural features, including columnar grain growth, melt pool geometries, phase segregation, and potential surface defects such as porosity, spatter scars, and delamination. These findings provide a critical foundation for understanding the process–structure relationships that govern additive manufacturing of stainless steel alloys. The mechanical characterization of additively manufactured 304 and 410 stainless steel components revealed a complex interplay between process parameters, microstructural evolution, and mechanical performance. These were observed through the DED- and SLM-fabricated 410 SS both displaying higher hardness (221.79 HV and 218.19 HV, respectively) than the DED-fabricated 304 SS (153.47 HV), consistent with their martensitic nature.
increased creep, and reduced modulus due to porosity, residual stress, and incomplete phase transformation. These defects, inherent to DED and SLM, compromise surface integrity and long-term durability, highlighting the need for improved process control. Nanoindentation results...