Obtaining of Spherical Intermetallic Alloy Cr-Ta-W Powder for Usage in Laser Powder Bed Fusion Additive Manufacturing with High-Temperature Platform Heating

This paper presents the results of research into the possibility of obtaining a spherical powder of a promising heat-resistant alloy with intermetallic hardening based on the Cr-Ta-W system for subsequent application in selective laser melting (SLM) technology. This research addresses the critical challenge of producing crack-free, high-density components from brittle intermetallic alloys through laser powder bed fusion (LPBF), which is achieved by developing a novel combination of powder processing techniques and high-temperature platform heating. The study has successfully addressed the inherent brittleness and processing challenges of Cr-Ta-W alloys, which have previously limited their manufacturability. The alloy was obtained through a series of methods, including mechanical alloying, granulation, and plasma spheroidization. The obtained powders were found to possess all the necessary technological properties for use in the SLM process. In order to ascertain the most effective method of compaction by the SLM method, a series of iterative constructions were carried out at different stages. It is demonstrated that the formation of a compact material from Cr-Ta-W alloy powder without the presence of visible defects and without the disruption of their geometry is only possible when utilizing platform heating to a temperature of at least 800°C. Samples obtained from the alloy with intermetallic strengthening on the basis of the Cr-Ta-W system exhibited high mechanical characteristics at elevated temperatures (1150°C). These included a yield strength of σ_0,2 ≥ 700 MPa and a tensile strength of σ_B ≥ 900 MPa.