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 Zr56.2Ti13.8Nb5.0Cu6.9Ni 5.6Be12.5 melt. The microstructure of the resulting two phase material is i nvestigated by SEM, X-ray diffraction, and microprobe analysis. The composi te material, as well as single phase materials with the corresponding matri x and second phase compositions, are tested in uniaxial tension and compres sion. Young's Modulus, shear modulus and Poisson ratios are analyzed by ult rasonic sound velocity measurements. The composite material demonstrates st rongly improved Charpy impact toughness (by a factor of 2.5 compared to Vit reloy 1) and ductility (average fracture strain up to 8.3% in compression a nd 5.5% in tension). These remarkable improvements are explained by the eff ect of the mechanically soft and ductile second phase, which acts stabilizi ng against shear localization and critical crack propagation. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Lid. All rights reserved.