Crystalline to amorphous transformation in Zr–Cu–Al alloys induced by high pressure torsion

Zr–Cu–Al alloys with various Al contents were processed by high pressure torsion (HPT). It was found that HPT can induce a remarkable crystalline to amorphous transformation in these alloys, with an almost fully amorphous structure obtained after 50 revolutions. Microstructural investigations indicated that the transformation from crystalline to amorphous structure is strongly dependent on both the accumulative torsional strain and chemical composition. Higher accumulative shear strain and Al content led to more pronounced amorphization. The amorphization occurred preferentially in the martensite phases with twin structure in Zr50Cu40Al10. Differential scanning calorimetric (DSC) analysis revealed a similar glass transition temperature in the amorphous samples produced by HPT to those prepared by rapid quenching.