異質核凝固の原理を応用した高造形性・高強度を実現する3Dプリンタ用金属粉末

Abstract

Additive manufacturing, also known as 3D printing, can be used to fabricate 3D objects according to 3D CAD data. Among some metallic additive manufacturing technologies, powder bed fusion method is most suitable for the precise fabrication of complex shaped products. However, columnar grains along the build direction are a typical microstructural feature of the samples fabricated by the powder bed fusion method, since this method involves leaving built products at sufficiently high-temperatures for long time during. Meanwhile, Al alloys are grain refined during solidification in order to promote the formation of an equiaxed grain structure in the casting and to eliminate columnar grain formation. This is commonly achieved by adding a small quantity of Al-Ti-B master alloy with Al3Ti and TiB2 heterogeneous nucleation sites to the melt just prior to casting. In this study, therefore, heterogeneous nucleation sites, TiC particles, are added into Ti-6Al-4V powder for 3 D printer, to achieve better microstructure and better mechanical properties.