Mechanical properties of Al based alloys containing quasi-crystalline phase as a main component

The application of high-pressure Ar atomization to Al-Mn-TM and Al-Cr-TM (TM = Co, Ni) ternary alloys caused the formation of a coexistent Al + quasi-crystalline (Q) structure where the Q phase is included as a main constituent phase. Subsequently, a bulk alloy consisting of Q and Al was produced by extrusion of the atomized powder. The particle size and inter-particle spacing of the Q particles are 150 and 140 nm, respectively and the volume fraction is about 60%. The mixed phase alloy exhibit high tensile strength and elongation of 720 MPa and 6.4%, respectively for Al93Mn5Co2 alloy. The Youngʹs modulus is also as high as 92 GPa. The Al-based alloy exhibits a small coefficient of thermal expansion of 20 × 10−6 K−1 between 373–473 K which is about 20% smaller than those for conventional Al alloys. These superior mechanical properties are presumably due to the fine dispersion and high volume fraction of Q particles and the high rigidness of the Q phase.