Study of Mechanical Characteristics of Stainless Steel Samples Obtained by Direct Laser Deposition

The paper presents the results of mechanical tensile tests and microhardness of samples obtained from stainless steel 316L powder by direct laser deposition. The strength characteristics of the deposited samples are better than those of rolled ones obtained in the traditional way. The material strength is reduced and its plasticity is increased with the growth of the laser radiation power during deposition. The obtained regularities are explained by analysis of the microstructure. It is found that the hardness of the cladding is substantially higher than that of the substrate material with the corresponding composition. This is a consequence of hardening of each layer during deposition of the next layer and formation of nanosized spherical inclusions representing oxides of metals that make up the powder in the sample bulk. The density of these particles affects the overall hardness of the material and depends on the radiation power supplied. Individual properties of the material for various applications can be modified by appropriate selection of technological parameters of the printing process.