Effect Of Rolling On Mechanical Properties Of Al₈₈Ni₄Y₈ Amorphous Alloy

Aluminum-based amorphous alloy has excellent corrosion resistance,wear resistance and mechanical properties,and its tensile strength can be as high as 1000 MPa,which is a very promising material.However,aluminum-based amorphous alloys,like other amorphous alloys,have almost no plasticity at room temperature,and the failure mode is catastrophic fracture along a single main shear band,which greatly limits its application in industry and life.Therefore,limiting the slip of a single shear band and inducing the generation of multiple shear bands has been considered as a means to improve the plastic deformation ability of amorphous alloys.Multiple shear bands can be generated in many ways,such as the hindrance of the second phase in the amorphous composite material,and preset shear bands by deformation.In this paper,the Al₈₈Ni₄Y₈amorphous strip is selected,and the changes of the strip’s mechanical properties under tensile conditions are studied by controlling the rolling deformation,strip size,annealing temperature after rolling and other conditions.The study found that as the rolling deformation of the amorphous strip increased from0%to 28%,its tensile strength and hardness decreased from 600 MPa and 362 HV to 470MPa and 301 HV,respectively,and the fracture strain increased from 1.98%to 2.45%;the change of the strip width also affects the mechanical properties of the strip.As the strip width increases from 0.8 mm to 3.5 mm,the tensile strength and hardness of the strip after rolling increase from 480 MPa and 319 HV to 557 MPa and 330 HV,the fracture strain decreased from 1.87%to 1.62%.After the rolled Al₈₈Ni₄Y₈amorphous strip is annealed at 100-130℃,its tensile fracture strength and hardness are increased from 545 MPa and 360 HV to 675 MPa and 391 HV,and the fracture strain is reduced from 2.07%to 1.62%.After the amorphous strip is rolled,there are obvious shear bands on the side surface,which is conducive to the improvement of the plasticity of the amorphous alloy and sawtooth appear on the stretch curve.The strip rolling volume,strip width and annealing temperature changes after strip rolling did not cause strip crystallization.The fracture morphology of the amorphous alloy strip and the shear band near the side surface near the fracture can reflect the change of the mechanical properties of the strip.The formation and disappearance of sawtooth steps on the tensile stress-strain curve are directly related to the interaction of multiple shear bands.