METHOD FOR ULTRASONIC TREATMENT OF A MELT OF HYPEREUTECTIC SILUMINS

摘要

The invention relates to a metallurgy of light alloys in particular to methods for ultrasonic treatment of melts in a production of shaped castings from hypereutectic silumins of a piston group. The method consists of a degasification and a following modification of the melt by introducing in it modification additives which contain phosphorus. After the modification, the ultrasonic treatment of a melt stream is being performed and accompanied by a developed cavitation in such a way that a volume of a cavitation field conforms to a total volume of the melt passing through the area of ultrasonic treatment. The ultrasonic treatment of every element of the melt stream is performed during 0.15 s to 1.2 s depending on the concentration of said modification additives which represent 0.01 to 0.06 % of the total mass of the melt. The inventive method is directed at increasing the fatigue strength of castings at high working temperatures.