Abstract
The thermal expansion behaviour of Al₂O₃ fibre-reinforced magnesium composites was studied in the temperature range from room temperature to 375 °C. The linear thermal expansion curves of the composites show thermal hysteresis. After the first complete heating and cooling cycle irreversible changes of the specimen length are observed; permanent (residual) strains are measured. The coefficient of thermal expansion of the composites depends on the volume fraction of fibres. The temperature dependence of the thermal expansion coefficient for heating stage is different from that measured in cooling stage of the cycle. A rapid drop in the temperature variation of the coefficient occurs at a certain higher temperature during heating stage of the first cycle. The results are discussed.

Key words
thermal expansion, coefficient of thermal expansion, magnesium composite

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