액상가압공정으로 제조된 금속 연속섬유강화 비정질 복합재료의 미세파괴거동

• Published in: 대한금속·재료학회지, 46(8) Vol. 46; no. 8; pp. 524 - 537
• Main Authors: 이규홍, Kyu Hong Lee, 이상복, Sang Bok Lee, 이상관, Sang Kwan Lee, 이성학, Sung Hak Lee
• Format: Journal Article
• Language: Korean
• Published: 대한금속재료학회 01.09.2008; 대한금속·재료학회
• Subjects: amorphous alloy; composite; fracture toughness; Liquid pressing process; 재료공학
• ISSN: 1738-8228; 2288-8241

Zr-based amorphous alloy matrix composites reinforced with metallic continuous fibers were fabricated by liquid pressing process, and their fracture properties were investigated by directly observing microfracture process using an in situ loading stage installed inside a scanning electron microscope chamber. About 60 vol.% of metallic fibers were homogeneously distributed inside the amorphous matrix. Apparent fracture toughness of the stainless-steel- and tungsten-fiber-reinforced composites was lower than that of monolithic amorphous alloy, while that of the Ta-fiber-reinforced composite was higher. According to the microfracture observation, shear bands or cracks were initiated at the amorphous matrix, and the propagation of the initiated shear bands or cracks was effectively blocked by fibers, thereby resulting in stable crack growth which could be confirmed by the fracture resistance curve (R-curve) behavior. This increase in fracture resistance with increasing crack length improved fracture properties of the fiber-reinforced composites, and could be explained by mechanisms of formation of multiple shear bands or multiple cracks at the amorphous matrix and blocking of crack or shear band propagation and multiple necking at metallic fibers.