Production and apparatus for preparing non-dendritic and semi-solid alloy by low-voltage pulse electric field

Abstract

The invention relates to a low-voltage pulse electric field preparation method and special equipment for semi-solid metal slurry or blank. Preparation method: first melt the alloy and keep it warm in the heat preservation crucible. The upper and lower ends of the alloy melt are respectively connected to the positive and negative electrodes of the output end of the pulse power supply. Before the solidification starts, start the pulse power supply to perform pulse discharge on the alloy melt. Apply a pulsed electric field. Special equipment: It consists of three parts: pulse electric field generator, pulse electric field effect device and heating and heat preservation device. The pulse current generated by the pulse electric field generator is applied to the alloy melt placed in the heat preservation device through the pulse electric field effect device. Adjust the pulse discharge voltage, discharge time and pulse frequency according to the type and composition of the alloy, and control the solidification speed of the alloy during the pulse discharge, and finally obtain a non-dendritic semi-solid alloy blank or slurry with a spherical or granular primary phase , can be used in the production of metal semi-solid alloy preparation and forming.

Description

technical field [0001] The invention belongs to the technical field of semi-solid metal processing, and in particular relates to a method and equipment for preparing non-dendritic semi-solid alloys using a low-voltage pulse electric field from semi-solid metal slurry or blanks. Background technique [0002] Since American scientists first proposed the concept of metal semi-solid forming in the 1970s, semi-solid metal processing technology has attracted extensive attention from the international materials community and has become one of the most active research fields today. This method can not only reduce costs, improve casting quality and yield, but also has the advantages of high efficiency, energy saving and environmental protection. At present, some developed countries have begun to apply it in the fields of automobile manufacturing, communications, electrical appliances, computers and their auxiliary equipment, aerospace and other fields, and have broad development pros...

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Problems solved by technology

The mechanical stirring method has the following disadvantages: (1) the life of the stirring chamber and the stirring rod is not long, the metal is more prone to oxidation and pollution, and the internal quality of the metal is very low; (2) there is a dead angle of stirring, which affects the uniformity of the slurry; (3) the equipment Bulky, difficult to operate, low production efficiency, the solid phase fraction can only be limited in the range of 30% to 60%

However, the electrical pulses they use are high or ultra-high voltage, generally from several thousand volts to tens of thousands of volts, such a high voltage brings great inconvenience to the operator, and the safety performance is relatively poor; and in the pulse discharge In the experiment, the metal or alloy is cooled naturally in the air or cooled with the furnace, the controllable time of the solidification process is short, and the control effect of the pulse electric field on the solidification structure cannot be fully exerted.

More importantly, none of them used electrical pulses to produce non-dendritic spherical semi-solid alloys

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