抄録
The harmonic-structured composite that consists of a network fine grain region with a high speed steel and a dispersed coarse grain region with a mild steel was fabricated prepared using a mechanical milling and spark plasma sintering process. The microstructure of harmonic-structured composite compact was observed by a scanning electron microscope and mechanical properties were evaluated by a tensile test and Vickers hardness test. The harmonic-structured composite exhibited high strength and enough ductility compared with a conventional particle-dispersed composite with the same volume fraction of high speed steel/mild steel. The work-hardening rate of harmonic-structured composite is higher than the conventional particle-dispersed composite so that the harmonic-structured material demonstrates a high elongation. The microstructure observation of harmonic-structured composite reveals that the superior elongation of the harmonic-structured composite is attributed to the plastic deformation of the dispersed area around the cracks which initiate at the network area.
