Properties of cold-deformed powder materials 12Cr18Ni10Ti AND AlSi10Mg obtained by selective laser melting

The article considers a combined technology which mixes selective laser melting (SLM) and longitudinal rolling of powder materials 12Cr18Ni10Ti and AlSi10Mg. The objective of the work is to experimentally establish the regularities of pressure treatment on the mechanical characteristics of the obtained SLM materials, namely on hardness and bending strength. A literature review was prepared, based on the information from which a batch of test samples were made from powders of stainless steel 12Cr18Ni10Ti and aluminum alloy AlSi10Mg. Pressure treatment of the resulting samples was performed using longitudinal rolling technology. The assessment of the high-altitude deformation of the 12Cr18Ni10Ti alloy samples was carried out using true (logarithmic) high-altitude deformation. The morphology of the raw materials was studied using an electron microscope. The mechanical properties of the materials were assessed by HRB hardness and bending strength. The results of radial compression tests on annular samples manufactured under similar technological parameters were analyzed additionally. Based on the results of the analysis, the dependence between stress and deformation was established, where for AlSi10Mg there is a smooth shape change under load, and for 12Cr18Ni10Ti there is a critical stress, at which an increase in deformation dynamics is observed. Scanning electron microscopy of the fractures of the AlSi10Mg material showed a more homogeneous structure of the rolled sample compared to the sample in the initial state, which is evidence of the positive effect of pressure treatment (within certain limits) on the density of the AlSi10Mg material obtained by the SLM method. Based on the results of the researches, a hypothesis about the interdependence of high-altitude deformation and hardness of the cold-deformed material 12Cr18Ni10Ti obtained by SLM was formulated and confirmed by the results of experiments. The bending strength limit of the AlSi10Mg powder material was established and the maximum bending loads for the 12Cr18Ni10Ti alloy was fixed. The dependences between stress and deformation of materials under radial compression and bending are shown. It has been found that longitudinal rolling of 12X18H10T powder material helps to reduce the resistance to bending force, but at the same time the hardness and elastic properties increase.