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Hafnium carbide strengthening in a tungsten-rhenium matrix at ultrahigh temperatures

Journal Article · · Acta Metallurgica; (United States)
; ;  [1]
  1. Arizona State Univ., Tempe, AZ (United States). Dept. of Chemical, Bio and Materials Science Engineering

Tungsten--rhenium--hafnium carbide (W---Re---HfC) alloy is the strongest metallic material at temperatures greater than 2000 K. In the this paper, the mechanical properties of tungsten and a W--3.6Re--0.26HfC alloy were determined from 1700 to 2980 K in a vacuum below 10[sup [minus]5] Pa. hfC particles had an exceptional strengthening effect n the tungsten-rhenium matrix at temperatures up to 2700 K. The strengthening was attributed to the high thermodynamic stability of HfC particles at ultrahigh temperatures. The growth behavior of HfC particles in the tungsten-rhenium matrix is examined. Carbon is found to be the rate-limiting element in the growth process of HfC particles. The strengthening mechanisms in a W--3.6Re--0.26HfC were discussed. It was concluded that the strength of a dispersion-strengthened material was proportional to the square root of the volume fraction of the particles. The calculation of a W--3.6Re--0.26HfC alloy's yield strength, calculated based on the dislocation pinning and the particle statistical distribution, was in good agreement with the experimental data over the entire temperature range.

OSTI ID:
6986406
Journal Information:
Acta Metallurgica; (United States), Journal Name: Acta Metallurgica; (United States) Vol. 40:9; ISSN 0001-6160; ISSN AMETAR
Country of Publication:
United States
Language:
English