METHOD FOR MANUFACTURING SCREW OF MAGNESIUM ALLOY AND MAGNESIUM ALLOY SCREW

摘要

PROBLEM TO BE SOLVED: To provide a screw made of a magnesium alloy excellent in heat resistance and to provide a manufacturing method of a magnesium alloy suitable for the manufacture of the screw. SOLUTION: A thread-formed body is composed of a shaft with a thread and a head contiguous to the shaft and is subjected to a first heat treatment at a heating temperature of not lower than 350°C. The thread-formed body comprises the magnesium alloy containing 4.0 to 10.0 mass% Al. A magnesium alloy screw, which satisfies an X-ray diffraction peak strength Xpof≤0.55 and has such a relatively coarse crystal structure as to be the average crystal particle diameter of 10 to 40μm, can be obtained by subjecting a magnesium alloy containing a specified amount of Al to a heat treatment at 350°C or higher. The magnesium alloy screw has excellent creep characteristics. COPYRIGHT: (C)2007,JPO&INPIT