Formation of the Structure of Powder Materials Based on Silicon Carbide by Explosive Compaction
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ICAL TECHNOLOGY
Formation of the Structure of Powder Materials Based on Silicon Carbide by Explosive Compaction A. V. Krokhaleva, V. O. Kharlamova,*, S. V. Kuz’mina, and Academician V. I. Lysaka Received June 8, 2020; revised August 26, 2020; accepted September 3, 2020
Abstract—The possibility of producing powder composite materials in the SiC–Ti system by explosive compaction without subsequent sintering was studied. It was found that, under these conditions, the densification of SiC and Ti powder mixtures is due to the interparticle displacement and deformation of particles of the carbide phase. It was shown that the main condition for the consolidation is the heating of the initial powder mixture by shock-wave compression to temperatures above 780°C. Keywords: silicon carbide, titanium, explosive compression of powders DOI: 10.1134/S0012500820100018
A unique combination of the mechanical and physicochemical properties of silicon carbide promotes the wide use of materials based on it in various industries. There are a lot of methods to produce such materials [1], each of which has certain advantages but, at the same time, is not free from some shortcomings. In this context, investigations of the possibility of using explosive compaction for manufacturing materials based on SiC [2, 3] are of both theoretical and practical importance. In these investigations, the metallic binder of a silicon carbide material was titanium, which gave a good account of itself in the explosive production of powder hard alloys based on chromium carbide Cr3C2 [2]. Explosive compression was performed by loading a layer of the initial mixture of SiC and Ti powders on the surface of a massive steel support with a normally incident plane detonation wave through an intermediate steel plate, which separated the explosion products from the powder [2]. Variation of the height of the explosive charge enabled one to vary the temperature of the self-heating of the powder mixture in the course of the shock-wave compression within the range 700– 840°C and the pressure within the range 11.5–16.5 GPa. The duration of the maximum-pressure pulse was 0.3 μs. The investigations showed that the explosive compaction of mixtures of a silicon carbide powder with a titanium powder can be carried out without the possi-
aVolgograd State Technical University, Volgograd, 400005 Russia *e-mail: [email protected]
ble [4] chemical interaction between them, despite the significant self-heating temperatures during the shock-wave compression (Fig. 1). The loading under the conditions ensuring the selfheating of the powder mixtures to temperatures above 780°C gave rise to a monolithic structure in which the titanium particles (Fig. 2a) retained their sizes and formed individual inclusions in the continuous silicon carbide matrix (Fig. 2b). The SiC particles, which initially had a splintery shape (Fig. 2c), turned out to be significantly deformed, which led to the formation of a tight contact between them (Fig. 2d). The air contained in the initial powder mixture was
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