PURPOSE: To obtain a crystal grain fragmentation judgment device capable of simply and surely judging the crystal grain fragmentation effect for magnesium alloy melt before injection.
CONSTITUTION: A judgment device of crystal grain fragmentation effect for magnesium alloy melt is provided with a means to detect a primary crystal coagulation temperature of the melt before fragmentation processing of the magnesium alloy and/or cooling rate just after the primary crystal coagulation initiation and a means to detect the primary crystal coagulation temperature of the melt after fragmentation processing of the magnesium alloy and/or cooling rate just after the initial crystal coagulation initiation. Also provided is a means to judge the degree of crystal grain fragmentation by comparing the detected primary crystal coagulation temperature of the melt before and after fragmentation processing and/or cooling rate just after the primary crystal coagulation initiation or the difference in the detected value and after fragmentation processing, with a standard value set in advance.
KUSAKABE HATSUO
YONEKURA KOJI
MIYAMOTO TAKAO
OTSUKA YUKIO
TOYOTA MOTOR CORP