Abstract: Disclosed are biodegradable magnesium having a biodegradation rate which is determined by controlling an atom packing density of a surface contacting a living body, and a method for controlling the biodegradation rate of magnesium, wherein the biodegradation rate is determined by controlling an atomic packing density of the surface in contact with a living body.

Abstract: The present invention provides a heat-resistant magnesium alloy for gravity casting, which has excellent high-temperature resistance, tensile strength, and creep resistance properties. In preferred embodiments, the present invention provides a heat-resistant magnesium alloy for gravity casting with high creep resistance, the magnesium alloy containing magnesium as a main component, 1.00 to 3.00 wt % neodymium, 2.00 to 6.00 wt % misch metal, 0.10 to 1.00 wt % zinc, 0.10 to 1.00 wt % zirconium, 0.01 to 0.50 wt % yttrium, 0.01 to 0.10 wt % calcium, 0.008 wt % silicon, 0.004 wt % iron, 0.003 wt % copper, and 0.001 wt % nickel.

Abstract: The present invention relates to the a method for manufacturing high strength ultra-fine/nano-structured aluminum/aluminum nitride or aluminum alloy/aluminum nitride composites using mechanical milling or mechanical alloying process which is conducted in the nitride-forming atmosphere such as nitrogen gas (N), ammonia gas (NH) or mixed gas including both gases, subsequent heat treatment process, and hot consolidation process. Also, high strength ultra-fine/nano-structured Al/ALN or Al alloy/ALN composite materials fabricated by the method of present invention have superior mechanical strength and heat resistance to those fabricated by conventional powder metallurgy process or liquid processes.