Magnesium alloy billet
Magnesium alloy billet which is the raw material feed to the magnesium extrusion machine and roller, is the first step and the key factor for the next process of producing the magnesium extrusion profile, wheels, plate, sheet and magnesium coil. Due to the lower melting point, alive chemistry and lower density, it is very difficult for people to get pure and evenly construction in the magnesium alloy billet, also it is the restriction to the mass production of magnesium sheet and extrusion for the time being.
Magnesium billet facility adopted the LFEC (low frequency electromagnetic casting) tech to cast the semi solid magnesium billet with the semi-continuous casting process. We share the patent and master the key technology of the way to cast the semi-solid magnesium alloy billet via semi-continuous casting process adopting the magnesium alloy LFEC tech which owned by the Northeast University.
We have the knowhow and our core technology of production of the magnesium alloy billet. The basic principle and working step of this technology is that:
Drop the fully pre-cleansed magnesium alloy melting liquid into graphite module with the electromagnetic fields working covering it, in the semi-solid forming process of the magnesium billet.
In the regular variations of low-frequency electromagnetic field while casting the magnesium alloy billet, also under the action of magnesium alloy melting alternately, the melting magnesium liquid is kept in tumbling, rotating and vibrating to exclude gas mingled in the melting liquid, to make the crystal small, uniform particle, and maintain in melt condition.
When melting liquid is longitudinally annularly tumbling in graphite mould, impurity was left on the magnesium alloy billet surface and outer, and then eventually slowly condensed and forms circular impurities scarfskin of the magnesium billet, due to the different proportion and electric conductivity.
Meanwhile, on the force driven of the alternate transverse circumference magnetic field in the magnesium alloy billet, the crystal of the magnesium alloy melting liquid are act as circular motion in liquid-solid two-phase state to make magnesium alloy crystal not grow and tree dendrites not form in the magnesium alloy billet.
On the various action of the electromagnetic field in the magnesium billet, the alloy element could melt and mixed with magnesium well, distributed evenly in the magnesium alloy billet until solidification. These could assure no segregate in the billet.
The above is the basic principle of low frequency electromagnetism semi-continuous cast for magnesium alloy billet. There’re many more technology and equipment in practical production to ensure the smooth realization of the production process, such as magnetic material join, gas protection facilities, magnetic field frequency and casting the magnesium alloy machine speed cooperation, cooling method and continuous casting magnesium billet technology, etc.
In the process of casting the semi-solid magnesium alloy billet, the impurities are lined up to edge, it finally prevent the growth of the grain and tree dendrites, eliminate the inclusion gas and detailing grain, and the internal organizational structure of the magnesium billet is optimized due to adopting the technology of the magnesium low frequency electromagnetic casting.
The features of the semi solid magnesium alloy billet come from the semi continuous casting process adopted magnesium LFEC technology are as below:
the content of the impurity in the magnesium billet is within 1/10000.
the quite small size of the well-distributed equiaxial crystal is less than 55um.
without porosity and segregation in the magnesium billet.
outside surface smooth and no crack on the magnesium billet.
This LFEC semi solid magnesium alloy billet is suitable for forging, extrusion and preparation of high strength of magnesium parts.
we can manufacture the magnesium billet of diameter between Dia 120 and Dia500mm, the max length is 7000mm. The trademark cover AZ, ZK, ZE, AM,MgGdY ….
The grain size of the magnesium alloy billet is controlled in 110-170 um normally.
