921 医療ステント用マグネシウム合金管の冷間引抜き加工

抄録

Magnesium alloy is used for many products. It is also expected to be a new material for medical tube, because of its possibility of systemic absorption. However, it is known that cold-plastic working of magnesium alloy is very difficult. In this study, fabrication of a magnesium-alloy medical tube by cold drawing was attempted. Fineness, thinness, adequate strength and high-quality surface are required for the medical tube. Firstly, plug drawing was carried out to satisfy the requirements. But, it was impossible to apply this method because of too brittle. Secondly, soft-metal mandrel drawing was tried. Drawing was possible, but it was difficult to extract the mandrel and there was a possibility that the tube might break due to its high drawing stress. So newly-devised fluid-mandrel drawing was carried out. As a result, it was found that the fabrication of medical tube by fluid-mandrel drawing was possible. It is easy to extract mandrel after drawing. And it is possible to prevent tube break during drawing, because drawing stress is lower than that of soft-metal mandrel drawing.