October 13, 2005

Saving energy & reducing air pollution by using hardened magnesium alloys

The use of magnesium alloys in engineering applications is becoming increasingly important as a relatively low density allows savings in energy consumption and therefore reduction in air pollution.

An associated reduction in inertia also makes these alloys potential candidates for friction components. Magnesium alloys, however, have low wear resistance and low hardness and sticking or seizure phenomena easily occur with the counter materials such as steel, copper and aluminum alloys.

In a paper published under AZojomo*, Katsuyoshi Kondoh, Ritsuko Tsuzuki and Eiji Yuasa, researchers at the Research Center for Advanced Science and Technology, University of Tokyo, investigated the effect that an addition of Mg2Si dispersoids would have on wear resistance and tribological properties of magnesium alloys.

For the purposes of this study, the magnesium matrix composite alloys with Mg2Si dispersoids were developed via solid-state processing.

The research found that the strength of the composite increases with increase in the Si content. This is due to the dispersion strengthening effect of fine Mg2Si particles distributed uniformly in the matrix.

In addition, the friction coefficient between the magnesium composite and S35C steel counter material increases with an increase in Mg2Si content, when wear test is carried out in an oil lubricant. This is because hard Mg2Si dispersoids attack the surface of the counter material.

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