The Microstructure and Thermal Stability of the Two-Component Melt-Spun Ni55Fe20Cu5P10B10 TCMS Amorphous/Amorphous Composite

Abstract

The aim of this study is to present the special features and properties of the two alloys of similar average chemical composition Ni55Fe20Cu5P10B10, processed through two different routes. The first alloy was melt-spun after the ejection of homogeneous liquid using a traditional single chamber crucible, and the second alloy was ejected from a double chamber crucible as two separate liquids: i.e., Ni40Fe40B20 and Ni70Cu10P20, mixing only at the orifice area. The studies of the microstructure of the composite alloy were performed through the use of transmission electron microscopy and scanning electron microscopy. The Ni55Fe20Cu5P10B10 two-chamber meltspun (TCMS) alloy, as well as the homogeneous Ni55Fe20Cu5P10B10, Ni40Fe40B20, and Ni70Cu10P20 alloys, were heated to elevated temperatures and their characteristics studied by means of differential scanning calorimetry. The temperature resistivity change method was applied to the examination of the Ni55Fe20Cu5P10B10 TCMS alloy. The phase composition after heat treatment was investigated using X-ray diffraction. The results of the microstructure examination show that the TCMS alloy is an amorphous/amorphous composite, and is notable for its Ni–Fe–B and Ni–Cu–P stripes resulting from its differentiated chemical composition. Another unique feature of the TCMS alloy is that it retains its wood-like morphology even after high-temperature heat treatment. The crystallisation of the TCMS alloy starts from the Ni–Cu–P constituent and ends with the Ni–Fe–B areas of the sample. The results are discussed on the basis of previous work completed on amorphous matrix composites.