INVESTIGATION OF MULTI-MATERIAL SAMPLES WITH THREE-DIMENSIONAL COMPOSITION CHANGE OBTAINED BY SELECTIVE LASER MELTING METHOD

Metallurgy and Materials
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Abstract:

The aim of this work was to develop a technology for the manufacturing multi-material VZh159/CuCr1Zr samples using selective laser melting with a change in chemical composition in three directions. The microstructure was investigated using an optical microscope, a scanning electron microscope was used to analyze the chemical composition, and the phase composition was estimated using X-ray diffractometer. Mechanical tests were carried out on universal testing machines. It was found that the microstructure of the CuCr1Zr alloy zone was columnar grains with epitaxial growth along the direction of sample fabrication. There is a interfacial zone between the two alloys, in which the alloys are mixed. It has an average chemical composition, no new phases are formed in it, and peaks corresponding to the phases for both alloys are observed. The interfacial zone continues to exist until the sixth layer of CuCr1Zr alloy is deposited and melted onto VZh159 alloy (approximately 300 µm). The multi-material samples showed mechanical properties more than 2 times higher values in tensile tests (430 MPa vs 203 MPa), but did not exceed the values for VZh159 (1202 MPa). The relative elongation in tension and compression of the multi-material sample was less than that of VZh159, CuCr1Zr and Inconel 718. The analysis of multi-material samples with a change in chemical composition in three directions showed that the presence of an alloy mixing zone in one printing layer of 350–400 µm will be sufficient to eliminate defects. The materials of the article were presented at the International Scientific and Practical Conference “Advanced Engineering Technologies (AET 2024)” held in St. Petersburg on May 13–17, 2024.