Abstract

BAYODE, Abiodun. Surface finish, microhardness and microstructure of laser metal deposited 17-4PH stainless steel. S. Afr. j. sci. [online]. 2022, vol.118, n.9-10, pp.1-5. ISSN 1996-7489.  http://dx.doi.org/10.17159/sajs.2022/11152.

Laser metal deposition is a metal-based additive manufacturing technology. It is a very sensitive and complex process because of the different process parameters involved and the interrelations between these parameters. A thorough understanding of the underlying physics of the process is essential in developing a comprehensive database of the properties of materials processed with this technology. The main objective of this study was to investigate the effect of laser power on a laser-deposited 17-4 precipitation hardenable stainless steel alloy. The as-built microstructure, phase composition, microhardness and surface finish were analysed. The results show that a defect-free sample with good metallurgical bonding and minimal dilution can be produced using high laser power in the range 1400-2600 W and a scanning speed of 0.6 m/s. The microstructure in the clad layer was dominated by martensite and an improvement in surface finish and maximum hardness was observed with increased laser power. SIGNIFICANCE: To fully benefit from the additive manufacturing technology, a comprehensive database of the material properties of alloys produced with this technology is required. This study expands on the body of knowledge related to the additive manufacturing of a 17-4PH stainless steel alloy, particularly highlighting the possibility of producing fully dense parts using higher laser power and scanning speed. These two parameters could significantly reduce the build time

Keywords : additive manufacturing; dilution; martensite; microhardness; microstructure.

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