Structure and Properties of Ta–Zr Alloys Produced by High-Speed Quenching from a Liquid State

Autor: A.Yu. Patrushev, D.P. Farafonov, A.I. Safaryan, M. M. Serov, R. A. Valeev
Rok vydání: 2021
Předmět:
Zdroj: Russian Journal of Non-Ferrous Metals. 62:448-452
ISSN: 1934-970X
1067-8212
DOI: 10.3103/s106782122104012x
Popis: This article analyzes the influence of high-speed melt quenching by extracting a suspended melt droplet of a Ta–Zr binary system. Two mixtures of powdered tantalum and zirconium are used with a tantalum content of 60 and 6%, respectively. The compositions after mixing were pressed under a pressure of 250 MPa in a steel mold on a hydraulic press. Sintering is carried out in a vacuum furnace at 1350°C and 10–3 Pa. High-speed quenching is carried out in vacuum under a pressure of 2 × 10–2 Pa by electron-beam heating and a rotating disk heat receiver. The thickness of the produced fibers is 15–80 μm. The experimental results of discrete fibers of Ta–Zr alloy and samples obtained by the fusing of the billet by electric beam hating (in an as-cast state) are analyzed and compared. It is established that the structure of rapidly quenched fibers of the alloy with 6 wt % Ta is comprised of grains of acicular shape with a size of 5–10 μm and the fibers with 60 wt % Ta have columnar dendrite structure. An analysis of the distribution of tantalum and zirconium across the transversal cross section of fiber demonstrates that, with a decrease in the cooling rate below 105 K/s in the alloy with a tantalum content of 60 wt %, monotectoid transformation occurs. It is revealed that the microhardness of rapidly quenched fiber of the alloy with 6 wt % Ta is 1.5 times higher than that of the same alloy without quenching, and for the alloy with 60 wt % Ta the same comparison demonstrates double dominance.
Databáze: OpenAIRE
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