In-situ microstructure engineering in stainless steel 17-4 PH fabricated by laser powder bed fusion

The current study explores the potential for in-situ microstructure engineering in precipitation-hardening stainless steel 17-4 PH during the LPBF process. Two approaches –laser modulation and laser remelting – were employed during fabrication. Key processing parameters, including duty cycle and frequency for laser modulation, or remelting enthalpy for laser remelting, were systematically investigated. Microstructural variations resulting from these strategies were characterized using various methods. The findings show that the as-built microstructures and the resultant properties can be effectively tailored, offering new pathways for property optimization in additively manufactured 17-4 PH components.