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A novel low-density steel with high aluminium content was, for the first time, manufactured as coils by the conventional industry process consisting of continuous casting followed by hot-rolling and cold-rolling. The duplex δ-TRIP microstructure, comprising a mixture of blocky retained austenite and both δ- and α-ferrite, was then produced by laboratory-scale heat treatments. The microstructure generation was achieved by an intercritical annealing followed by direct quenching, which was the same process as that for producing conventional dual-phase steels. The alloy exhibits quite interesting mechanical properties with a combination of 930 MPa tensile strength and of 21% total elongation, both in rolling and transverse directions. The formability of this novel alloy was assessed and discussed.

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The effect of different Cu-P admixtures and cooling rates on microstructure and wear behavior of hypereutectic Al-50Si alloys were studied systematically in this work. The growth patterns and the modified as well as over-modified mechanisms of primary Si crystals under various P contents are also illuminated in detail. It was found that the optimum content of the modifier in Al-50Si alloy is 3 wt%. At this modifier content, the mean size of Si crystallite is the smallest and the distribution is also the most homogeneous. Vickers hardness and wear test were employed to detect the mechanical performance of materials. The maximum value of hardness and the minimum value of average friction coefficient obtained under the modifier content of 3 wt% are 198 HV and 0.407, respectively.

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