Microstructure and mechanical properties of an aluminum alloy reinforced by Al–Ni–Co–Mn quasi-crystalline

Abstract

The Al72Ni13Co10Mn5 quasi-crystalline was prepared by conventional casting method. The microstructures and the phase composition of Al72Ni12Co16 quasi-crystalline, Al70Ni11Co12Mn7 and Al2Ni phases were characterized by XRD, SEM and DSC. The (Al72Ni13Co10Mn5)p/ZL101A aluminium based composite was fabricated by using the Al72Ni13Co10Mn5 quasicrystals particles as the reinforcing phase and ZL101A as the matrix with electromagnetic stirring. The results showed that the Al72Ni13Co10Mn5 is a QC(quasi-crystalline) phase and the hardness of Al72Ni13Co10Mn5 is higher than d-Al72Ni12Co16; the as-cast (Al72Ni13Co10Mn5)p/ZL101A composites are composed of α-Al, eutectic Si, θ, γ and φ phase. With the increase of reinforcing particle fraction, the changed order for the morphology of coralline Si as follows: coral distribution → partially converted into strips → strip or thick sheet. The changes of mechanical properties were studied by tensile test and the resulting crystalline phase γ and φ phases contribute to the improvement of the mechanical properties of the composite. After adding 4%wt% quasicrystalline particles, the tensile strength increased by 20.3%. However, when additional increased to 7 wt% will cause agglomeration and clusters of the θ phase, which leads to the decrease of the mechanical properties.