기계적 합금화 방법으로 산화물을 분산시킨 텅스텐 중합금의 동적 변형거동

Abstract

The objective of this study is to investigate the dynamic deformation and fracture behavior of an oxide-dispersed tungsten heavy alloy fabricated by mechanical alloying. The tungsten alloy was processed by adding 0.1 wt.% Y₂O₃ powders during mechanical alloying in order to form fine oxides in tungsten/matrix interface. Dynamic torsional tests were conducted for this alloys, and then the test data were compared with those of a conventionally liquid-phase sintered specimen. The refinement of tungsten particles could be obtained after mechanical alloying and multi-step heat-treatment without an increase in volume fraction of the interfacial area between tungsten particles occurred over broad deformed areas in this alloy , expecting the low possibility of the shear band formation. Also, the oxide dispersion strengthening was effective in promoting the interfacial fracture since fine oxides acted as a initiation site of interfacial fracture. These findings suggested that the idea of forming fine oxides would be useful for improving the self-sharpening effect and the penetration performance of tungsten heavy alloys.