Complex shape metallic glass composites produced in one step by mini-thixoforming

Abstract

Mini-thixoforming is a technique based on forming in semi-solid state: the material becomes partially melted, retains a fraction of solid phase and is able to fill intricate cavities in a single forming step. In this study, metallic glass composites were produced by a combination of powder metallurgy and processing of material in semi-solid state. The experimental program was composed of processing mechanically compressed powder in semi-solid state. The powder mixture consisting of iron powder + metallic glass powder. Metallic glass was obtained in the form of a rod and prior to semi-solid processing was characterized by scanning electron microscopy (SEM), light microscopy and micro-hardness test. The rod was milled and obtained powder was mixed with Fe powder. In order to achieve a better compaction, the mixture was mechanically compressed before heating to a semi-solid state. After the semi-solid processing was carried out, homogenous composites reinforced with Fe powder were obtained. Characterization of the produced structures and comparison of final structures at different temperatures were carried out again by DTA-TG, XRD, SEM-EDX, light microscopy and micro-hardness test, and the analysis results of composite structures have been compared with the initial ones. It was concluded that one step formation process of compact composite was successfully completed.