A Kind Of Zr Amorphous Alloy In Supercooled Liquid Study On Constitutive Relation

Amorphous alloy with excellent comprehensive performance, the performance of amorphous alloys in supercooled liquid region surplus plasticity, suitable for forming of amorphous alloys. This article selects the forming ability of(Zr33.2Ti36.1Ni5.8Be24.9)91Cu9 amorphous alloy, by X-ray diffraction analysis(XRD) and differential scanning calorimeter instrument(DSC) to(Zr33.2Ti36.1Ni5.8Be24.9)91Cu9 amorphous alloy for structure analysis and differential thermal analysis; Using arc melting/copper die-casting needed for the preparation of amorphous alloy material; In Exceed series universal test machine(MTS) is adopted to improve tensile experiment of(Zr33.2Ti36.1Ni5.8Be24.9)91Cu9 amorphous alloys in supercooled liquid region, by scanning electron microscope(SEM) to(Zr33.2Ti36.1Ni5.8Be24.9)91Cu9 amorphous alloys in supercooled liquid region of fracture morphology under tensile experiment observated. The experimental results are as follows:By XRD as-cast(Zr33.2Ti36.1Ni5.8Be24.9)91Cu9 alloy for amorphous structure, the amorphous alloy was determined by the DSC glass transition temperature Tg=612K, crystallization start temperature Tx=671K, as supercooled liquid region delta ?T=Tx-Tg=59KTemperature is below 617 K or strain rate is above 0.75×10-3s-1,(Zr33.2Ti36.1Ni5.8Be24.9)91Cu9 amorphous alloys occured stress overshoot phenomenon. With the increase of strain, the stress overshoot of non-newtonian flow deformation into newtonian flow. Temperature is above 622 K or strain rate is below 0.5×10-3s-1,(Zr33.2Ti36.1Ni5.8Be24.9)91Cu9 amorphous alloys is newtonian rheological stress overshoot does not occur.In the process of newtonian rheological, fracture appear a large number of radial vein pattern and a small amount of molten droplets. With the increase of strain rate and temperature is reduced, fracture of(Zr33.2Ti36.1Ni5.8Be24.9)91Cu9 amorphous alloys by radial vein pattern gradually transformed into a feather item type or leaf shape pattern, the amorphous alloy by ductile fracture to brittle fractureUsing extended index model, free volume model, Maxwell-Pulse model for(Zr33.2Ti36.1Ni5.8Be24.9)91Cu9 amorphous alloys under tensile experiment conditions fitting: Free volume equation can characterize(Zr33.2Ti36.1Ni5.8Be24.9)91Cu9 amorphous alloys under the condition of tensile experiment of stress overshoot and steady state flow deformation, for a particular area fitting curve with the experimental data is different. Extended index equation characterized(Zr33.2Ti36.1Ni5.8Be24.9)91Cu9 amorphous alloy in tensile experiment under the condition of steady state flow deformation, not fitting the maximum stress chongzhi, use range is limited. Maxwell-Pulse constitutive equation represented(Zr33.2Ti36.1Ni5.8Be24.9)91Cu9 amorphous alloy in tensile experiment under the condition of steady state flow deformation and stress overshoot phenomenon.