Calcium-Containing Aluminum Alloys

The phase composition and microstructure of ternary alloys, Al–Ca–X (where X = (Silicon) Si, (Magnesium) Mg, (Zinc) Zn, (Copper) Cu, (Nickel) Ni, (Iron) Fe, (Manganese) Mn, and (Scandium) Sc), developed based on Ca-containing eutectics have been studied. In most systems, ternary compounds are detected. It is found that the structure of Ca-containing eutectics is much finer than that of Al–Si alloys. Such alloys have a good combination of technological properties during casting and deforming. Because of the high volume fraction of Ca-containing particles (up to 33 vol.%), they may be considered as promising “natural composites.” The strength properties of Al–Ca–X alloys may be significantly enhanced by adding Sc and Zr, forming L12 nanoparticles. Alloys of the system Al–Zn–Mg–Ca can reach hardnesses higher than 200 HB, which gives reason to expect good strength properties. With the example of the Al–9%Zn–3.5%Mg–3%Ca model experimental alloy based on the (Al) + (Al,Zn)4Ca eutectic, the possibility, in principle, of manufacturing rolled sheets has been demonstrated.