January 20, 2010,13:09 +0900(JST) The World’s First Commercial Production of AZ91 Magnesium Alloy Sheet
When you were a student, did you use mnemonics for the periodic table, which contains H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S and others? The 12th element, magnesium (Mg), whose specific gravity is about 2/3 that of the 13th element, or aluminum (Al), and 1/4 that of iron (Fe), is the lightest among structural metals. Magnesium, which is abundant in nature, is known to be virtually inexhaustible. The bittern used in preparing tofu is also a magnesium compound. Magnesium is recyclable through a low energy process, and has therefore been the focus of attention as an environmentally friendly, lightweight material.
AZ91 alloy is a magnesium alloy to which are added approx. 9% of aluminum and 1% of zinc, in order to improve corrosion resistance. No sheet of this alloy existed due to the difficulty of rolling and forming. Sumitomo Electric developed its own original casting and rolling method on the basis of technology developed through wire production, and has succeeded in mass producing AZ91 magnesium alloy sheet for the first time in the world.
In terms of strength and corrosion resistance, this new alloy sheet surpasses AZ31 sheet (Mg with 3% Al and 1% Zn), which is already in use. It has a smooth surface due to its fine crystal structure. AZ91 sheet exhibits substantially higher elongation and strength than AZ91 cast material. It is suitable for press working, aesthetically pleasing coatings, and surface treatment, making optimal use of its beautiful metallic texture. This alloy sheet has superb vibration and shock absorption, and dent resistance in the event of dropping or other impact and is expected to find widespread applications, such as in portable devices and in-vehicle components.
You cannot experience the sensation of lightness or the actual luster via my blog, but these cases are surprisingly light in the hand. Magnesium is a beautiful metal, as indicated by the Chinese character for magnesium, which consists of the symbols for “metal” and “beauty.” The prototypes truly demonstrate the metal’s bright beauty. Incidentally, I like the nearest elegant tortoiseshell colored case.
This success was brought about through years of effort by our researchers. Their efforts will be wasted unless the products are put into commercial use. The AZ91 alloy sheet appeared on the front page of the Nikkei Business Daily dated January 14. We will promote the sales of this novel material, so that you will be able to see the product firsthand on an early occasion. Your support would be most appreciated.