2006 Volume 47 Issue 546 Pages 627-631
The use of magnesium and its alloys, which have excellent vibration damping properties, as materials for parts of acoustic equipment, such as the diaphragm used in speakers or tweeters, is now being considered. However, a foil of 50-100μm thickness is required for acoustic equipment, and it is considered difficult to press such a foil made of magnesium and its alloys into the desired shapes. In particular, magnesium foil, which must be processed through warm forming, is expected to be more difficult to form than other metal foils. In this study, we initially used an AZ31 magnesium alloy foil and a pure magnesium foil, which has a higher vibration damping property than an alloy foil, to evaluate the formability in the warm forming of these foils using two press forming methods: stretch forming and deep drawing. Next, on the basis of the examination results, we proposed two forming methods for the manufacture of a dome-shaped diaphragm for a tweeter and succeeded in forming a diaphragm made of pure magnesium foil using these methods.
