The effects of laser wire directed energy deposition processing parameters on the properties of 309L stainless steel

Abstract

Laser directed energy deposition technology using 309L welding wire feedstock was investigated in this research work. The aim of the study was to determine the effect of laser power and scanning speed on the microstructure and hardness of the 309L austenitic stainless steel. The travel speed and the laser power were varied from 350 mm/min to 650 mm/min, and from 700W to 1100W, respectively. The general microstructure of the test cubes was that of ferrite dendrites in austenitic matrix. The test samples fabricated at laser power between 700W and 900W showed lack of fusion. However, samples that were manufactured at laser power between 1000W and 1100W were of good quality and did not show any defects. The micro hardness ranged between 188HV0.1 to 211HV0.1.

A Review on Wire-Laser Directed Energy Deposition: Parameter Control, Process Stability, and Future Research Paths

“…This is supported by Mamphekgo et al using SS 309. As depicted in Figure 24, LOF defects were detected in their experiment between layers, and were resolved by increasing the laser power [59].…”

“…This is supported by Mamphekgo et al using SS 309. As depicted in Figure 24, LOF defects were detected in their experiment between layers, and were resolved by increasing the laser power [59]. Using wire feedstock instead of powder minimizes the formation of gas-trapped pores, and their formation is mostly observed in materials that readily oxidize (e.g., aluminum alloys) [47,61,63,[171][172][173].…”

“…It affects the amount of material being melted, its thermal cycle, and the quality of the final structure. As noted in the literature, the decision on the appropriate power depends on the type of material and the amount of wire that is being deposited [33,[56][57][58][59].…”