Inert gas absorption and pore formation in nickel-based hot-melt alloys

Abstract

An integrated approach to the generalization and analysis of scientific and technical literature in the direction of improving the technological processes of spraying metal melts used a comprehensive approach The processing and analysis of experimental data for the determination of argon at different stages of heat-resistant alloy production were performed. Micro structural analysis of nickel-based heat-resistant alloys obtained by gas and centrifugal spraying was performed. A significant increase in the mass fraction of argon in the melt is shown when held in a furnace before gas or centrifugal spraying, the absence of capture of inert gas by sprayed liquid particles during centrifugal spraying is shown, unlike the process of gas spraying, it is shown. The results of the study indicate the absence of "dissolution" of Ar or a mixture of Ar-He in the liquid or solid state at argon levels up to 1 • 10-4% of the mass. It is established that centrifugal spraying of metal melts allows obtaining compact powders with small particle size distribution at relatively low energy consumption. It is also noted that argon is captured by the metal only in the process of moving on the disk, and not due to the weak dynamic gas interaction directly on the melt droplets. Hence, its amount in the metal increases after the argon’s injection into the furnace chamber and at the subsequent centrifugal spraying does not change, in comparison with gas spraying. A technological possibility has been found to significantly reduce the amount of gas pores and the mass fraction of inert gas in nickel-based heat-resistant alloys. Nickel-based heat-resistant alloys obtained by the method of gas and centrifugal spraying make it possible to improve the quality of products for the aviation industry, their reliability when operating in extreme conditions.

Keywords

• gas spraying
• centrifugal spraying
• heat-resistant alloy
• argon
• helium
• pore formation.