Effect of Sr and La on the In Situ A356-TiB2 Composite Fabricated via Remelting and Diluting Approach

In this paper, a remelting and diluting (RD) approach was used to fabricate in situ A356-3wt.%TiB2 composites and the effect of Sr and La on the modification of the composites is investigated in comparison with the conventional flux assisted synthesis (FAS) approach. The microstructure was examined and tensile properties were tested to evaluate the modification efficiency on the composites. The results demonstrated that composites fabricated via RD approach achieve preferable modification by Sr and La due to the higher level of melt cleanliness so as to minimize the Sr-B interaction, in which the eutectic Si which displays a microstructure with globular-fibrous eutectic Si particles. Superior mechanical properties are obtained in the RD composites (especially the elongation) after modified by Sr and La.

Development of Non-SF6 Strip Casting Process for Mg Alloys

For non-SF6 process and melt cleanliness, CaO added AZ31 Mg alloy has been developed for strip casting. Mg alloys were usually ignited during conventional casting, the continuous casting and strip casting. Protective gases should be used in order to prevent the ignition of Mg alloys during melting and casting processes. However, protective gases have the disadvantages of global warming potential, high production cost and corrosion of steel based equipments. To solve ignition problem and overcome environmental issue, this paper discussed the effects of CaO addition and amount on strip casting process in terms of non-SF6 process and melt cleanliness.