Estimation of the internal stresses in amorphous glass-covered microwires

Abstract

A technique is developed to estimate the internal stresses in amorphous glass-covered Co69Fe4Cr4Si12B11 alloy microwires with micron-scale cross sections that are produced by melt quenching by the Taylor-Ulitovskii method. In the developed model, a microwire is considered as a microcomposite to take into account the internal stresses that are induced by the difference between the thermal expansion coefficients of glass and metal during rapid cooling from the solidification temperature to room temperature. The radial, tangential, and axial stresses are calculated in both a glass shell and a metallic core using experimental data on the elastic moduli and the geometric sizes of these structural components of a microwire. The mechanical properties are determined by selective nanoindentation of transverse polished sections of microwires.