Using Spark Plasma Sintering process (SPS), consolidation behavior of gas atomized alloys were investigated via examining the microstructure and evaluating the mechanical properties. In the atomized ahoy powders, fine particles were homogeneously distributed in the matrix. The phase distribution was maintained even after SPS at 723 K, although particles were newly precipitated by consolidating at 748 K. The density of the consolidated bulk Mg-Zn-Y alloy was . The ultimate tensile strength (UTS) and elongation were varied with the consolidation temperature.

Mg-4.3Zn-0.7Y (at%) alloy powders were prepared using an industrial scale gas atomizer, followed by warm extrusion. The powders were almost spherical in shape. The microstructure of atomized powders and those extruded bars was examined using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscope (EDS) and X-ray Diffractometer (XRD). The grain size of the powders was coarsen as the initial powder size increased. After the extrusion, the grain size became fine due to the severe plastic deformation during the extrusion with the ratio of 10:1. Both the ultimate strength and elongation were enhanced with the decrease of initial particle size.

본고에서는 고유한 원자구조에 기인한 우수한 특성으로 인해 구조재료 및 기능재료로서 그 활용이 기대되고 있는 벌크 아몰퍼스 소재에 있어 온간압출, 온간압연, 방전 플라즈마 소결(Spark Plasma Sintering)등 과냉각액체온도구간에서의 점성유동을 이용한 고화성형 공정의 최근 기술동향에 대해 간략히 소개했다.

This work is to present a new synthesis of metallic glass (MG)/metallic glass (MG) composites using gas atomization and spark plasma sintering (SPS) processes. The MG powders of (CuA) and (NiA) as atomized consist of fully amorphous phases and present a different thermal behavior; (glass transition temperature) and (crystallization temperature) are 716K and 765K for the Cu base powder, but 836K and 890K for the Ni base ones, respectively. SPS process was used to consolidate the mixture of each amorphous powder, being in weight. The resultant phases were Cu crystalline dispersed NiA matrix composites as well as NiA phase dispersed CuA matrix composites, depending on the SPS temperatures. Effect of the second phases embedded in the MG matrix was discussed on the micro-structure and mechanical properties.