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Magnesium Alloys

KURTZ Low-pressure casting machine for non-permanent moulds, suitable for both aluminum and magnesium casting

Magnesium: leightweight construction on the rise

Casting of aluminium alloys under low pressure is a process acknowledged all over the world for high-strain components. To achieve the requirement of weight saving, low-pressure casting of magnesium alloys is increasingly becoming the focus of attention for developers.

Magnesium is practically inexhaustible on our planet. As the eighth most frequent element, it forms about 1.4 % of the structure of the earth‘s crust. In 1808, Sir Humphrey Davy obtained magnesium for the first time in a coarse metallic form.

Magnesium alloys have a number of positive properties: high specific strength, extremely low material fatigue and excellent processing ability. Over and above this, they are extremely insensitive to impact and vibration strains. Some magnesium alloys also have a high heat resistance and can be used without any problems in the temperature range from 250 to 300 °C. But the most attractive property is that magnesium is 4.5 times lighter than iron and even 1.5 times lighter than aluminium. This is why it is also preferably used in aircraft and automobile construction.

Casting magnesium is not simple. The cast part production demands compliance with specific rules on all levels of the technological process. The melting temperature of magnesium is 651 °C. Under normal conditions, it is difficult to be melted: At up to 550 - 632 °C,magnesium ignites of its own accord and burns with a dazzlingly bright flame. Protective and counter-measures make this process more difficult.

For the casting of magnesium alloys, the KURTZ low-pressure machines are specifically adapted to the demands in question. In order to achieve a reproducible quality of the cast part, precise temperature control from the furnace via the riser tube to the die is necessary.

The KURTZ machine controls have been adapted for this purpose. The high precision of the KURTZ pressure control enables an even increase of pressure without fluctuations, thus preventing formation of oxide in the riser tube and in the mould. As a result of the complete system, including machine controls, pressure control and riser tube heating, KURTZ is in a position to offer customers process technique under one roof as well.

Close cooperation and a permanent exchange of information with the customers make it possible to put the requirements made by magnesium casting into practice in process-safe machine technique.