Investigation of TiB2–TiN eutectic alloy obtained by combustion synthesis for chemical resistance in mineral acid media

Abstract

The article presents the results obtained in the corrosion resistance study of TiB2/TiN eutectic alloy powder in HCl and HNO3 mineral acids. Experiments were carried out on samples synthesized in the combustion mode and then ground in an agate vessel. The morphology, size distribution and specific surface area of particles were determined in the obtained powder samples. Corrosion resistance experiments were conducted with varying acid concentration from 0.2 to 6.0 M and process temperature from 25 to 80 °C. Chemical analysis of the studied products of interaction with an aggressive medium was carried out to determine the content of main elements in them (titanium, boron, nitrogen) using methods developed for refractory compounds. As a result of the work carried out, it was shown that samples have the greatest resistance when interacting with solutions of diluted acids at room temperature, and their resistance decreases as acid concentration and/or process temperature rises. It was found that interaction with the acid occurs with both TiB2 and TiN phases in all cases considered in the paper. At the same time, the reaction involving the TiB2 phase was faster. For the first time deep corrosion and corrosion resistance of the alloy in HCl and HNO3 media were measured at room temperature and 1.0 M acid concentration. Based on the obtained data, the investigated alloy was classified as a «resistant» material. Corrosion resistance by a ten-point scale in HCl and HNO3 media was «4» and «5», respectively.