Investigation of the effect of scan direction on microstructural and mechanical properties in the manufacturing of 13-8 MO PH stainless steels by laser metal deposition (LMD) method

Additive manufacturing has become an attractive production method in industry and academia due to the advantages it provides in recent years. Additive manufacturing is a production method that increases the number of materials it can be applied to and provides design and production convenience. Laser metal deposition is a production technique belonging to the directed energy branch of additive manufacturing technology. In this study, the effects of scanning strategy, powder flow rate, scanning speed and overlapping parameters on microstructure and microhardness of PH 13-8 Mo stainless steel produced by LMD method were investigated. PH 13-8 Mo and AISI 1050 materials were used as deposition and base materials, respectively. Scanning strategy among production parameters is changed into 3 different techniques alternating uni directional, raster scanning strategy and uni-directional. Powder flow rate varies between 2,5-4,5 rpm, scanning speed in the range of 7-9 mm/s, and overlapping in the range of 35-45%. Differences in microstructure were observed with changing production parameters. Depending on the differences in microstructure, changes in microhardness were observed. The results obtained show that the laser scanning strategy in the laser metal deposition production method significantly affects the phase formations in the microstructure and with this effect, the mechanical properties change. It also showed that powder flow rate, scan rate and overlap rate had a significant effect on fusion formation, and mechanical and microstructural properties of the samples were also affected.