Materials design and second phase control for trade-off-balancing between strength and ductility in metallic materials

摘要

Enhancement in strength often deteriorates toughness, ductility, conductivity, and other trade-off properties. However, high strength structural materials are always required so that they should have better toughness, higher ductility, higher conductivity, and so on. One of the best ways to improve trade-off properties simultaneously for alloys is to make use of plural structure or composite of microstructure. In some cases with ductile matrix phase, finer spacing of second phases can bring about not only higher strength but also higher ductility. This paper introduces an idea of ultrafine grained ferrite steel with finely dispersed iron carbides for high strength - high uniform elongation balance, and further recent accomplishments in related studies are shown.