The toughening of Al–Cu–Fe(-B) quasicrystals by Sn particles

The effect of soft Sn particles on the room temperature mechanical properties of as-cast Al–Cu–Fe(-B) quasicrystalline (QC) matrix composites has been studied by compression and three-point bending tests on notched specimens. Microstructural investigations indicated that the Sn particle size in the as-cast composites increased linearly with the volume fraction. The addition of about 10 vol.% Sn enabled a twofold increase of the strength for the cast Al–Cu–Fe and a threefold increase of the fracture toughness for the cast Al–Cu–Fe–B composites. The enhancement of the strength was attributed to micro-crack impediment and crack bridging mechanisms in the as-cast QC matrix composites with small and large Sn particle sizes, respectively.