Addition of AlTi alloy refiners into an Al melt induces grain refinement of ¡-Al grains in as-cast pure Al. In this study, the effects of cold rolling for the AlTi alloy refiners on the grain refinement of as-cast pure Al were investigated. The Al 3 Ti particles in the refiners, which act as nuclei for the ¡-Al grains, were fragmented by cold rolling. Grain size of the ¡-Al grains is decreased as increasing the reduction ratio of the refiners. This decrease in grain size is due to the increase in the number of Al 3 Ti particles in the refiners. The mechanical properties of the as-cast pure Al are also improved as a result of its grain refinement. In particular, the wear properties of the as-cast pure Al were drastically improved. It is concluded that the cold rolling for the refiners is an effective process to enhance its grain refinement ability.

Photonic crystal is a new type of optical material in which a refractive index or dielectric constant is periodically changed. It is easy to fabricate 3-D periodic structures using textile technology. The main goal of our study has been, therefore, to fabricate the flexible photonic crystals by using high-dielectric-constant fibrous material. For this purpose, in this study, the high-dielectric-constant fiber was fabricated by coating of TiO 2 particles onto the cotton-yarn by irradiation of ultraviolet light (UV), since the TiO 2 is a photocatalytic material.