Mechanical properties of Zr56.2Ti13.8Nb5.0Cu6.9Ni5.6Be12.5 ductile phase reinforced bulk metallic glass composite

Ductile phase containing bulk metallic glass composites are prepared via an in situ method by rapid quenching of a homogenous Zr56.2Ti13.8Nb5.0Cu6.9Ni5.6Be12.5 melt. The microstructure of the resulting two phase material is investigated by SEM, X-ray diffraction, and microprobe analysis. The composite material, as well as single phase materials with the corresponding matrix and second phase compositions, are tested in uniaxial tension and compression. Young's Modulus, shear modulus and Poisson ratios are analyzed by ultrasonic sound velocity measurements. The composite material demonstrates strongly improved Charpy impact toughness (by a factor of 2.5 compared to Vitreloy 1) and ductility (average fracture strain up to 8.3% in compression and 5.5% in tension). These remarkable improvements are explained by the effect of the mechanically soft and ductile second phase, which acts stabilizing against shear localization and critical crack propagation. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Lid. All rights reserved.