Ductile-to-Brittle Transition Characteristics in W–Cu Composites with Increase of Cu Content

Abstract

A series of tungsten-copper composites containing copper of 19–80 vol% were subjected to three-point bend tests at temperatures between 77 and 363 K. Temperature dependences of the yield strengths and the maximum strengths were examined for each W–Cu composite. Then the effect of Cu content on the ductile-to-brittle transition behavior of the composite was investigated. The results are summarized as follows. First the composites containing copper of less than 40 vol% demonstrated ductile-to-brittle transition behavior and the transition temperature tended to decrease with the increase of Cu content. The composites containing copper of more than 60 vol%, in contrast, demonstrated no distinctive transition. Secondly production method leading to the microstructure had a significant effect on the maximum strength and consequently on the ductility, though it had almost no effect on the yield strength.