Static mechanical characterization of a bulk amorphous and nanocrystalline Zr40Ti14Ni11Cu10Be25 alloy

Abstract

Abstract Bulk amorphous samples of a Zr40Ti14Ni11Cu10Be25 alloy were tested in compression at displacements rates from 10−4 s−1 to 10−1 s−1. No dependence of Young's modulus on strain rate was found. There was, however, a change in modulus on repeated cycling the load because of relaxation effects, up to a steady value of 102 GPa. Ductility was very limited since a maximum plastic strain at fracture of 1% was reached. The tensile strength was 2 GPa. Vein patterns due to strain localization were observed on fractured surfaces. Partially crystallized samples contained a nanocrystalline phase. The hardness increased with an increasing amount of nanocrystalline phase. The toughness decreased to values of 1–2 MPa√m as in brittle ceramics due to loss of intrinsic ductility of the amorphous matrix. Fracture surfaces displayed typical brittle behavior. The possibility of avoiding strain localization in the amorphous phase is discussed.