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.

Abstract The microstructure of 316L stainless steel obtained by layer-by-layer direct metal laser deposition is reviewed. Mechanical tests of the samples were performed in accordance with GOST 1497-84. Studies show that changes in power of laser radiation to grow parts lead to changes in their mechanical properties. The research shows dependencies between the strength characteristics of materials and the power of laser radiation. Causes of the forementioned changes are studied through the analysis of the microstructure. Nanosized inclusions of spherical shape were found in the process of studying the microstructure of materials. A study in the nature of the formation of these inclusions and their effect on the properties of the obtained material was performed.

The paper presents the results of mechanical properties study of the material produced by direct metal laser deposition of VT6 titanium powder. The properties were determined by the results of stretching at tensile testing machine, as well as compared with the properties of the same rolled material. These results show that obtained samples have properties on the level or even higher than that ones of the samples obtained from the rolled material in a certain range of technological regimes.