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The influence of the refilled gas pressure on the glass forming behaviour of one of the best ternary glass forming alloys Zr_(50)Cu_(40)AI_(10) was studied for the melt spinning process.The amorphicity of as-quenched ribbons was characterized by X-ray diffraction(XRD) and differential scanning calorimetry(DSC).The refilled chamber atmospheric pressure is crucial to the cooling rate of melt spinning.At high vacuum,at pressure less than 0.0001 atm,fully crystalline fragments are obtained.Monolithic amorphous ribbons were only obtained at a gas pressure of 0.1 atm or higher.The extended contact length between thecribbons and the copper wheel contributes to the high cooling rate of melt spinning.Higher chamber gas pressure leads to more turbulence of liquid metal beneath the nozzle;therefore,lower pressure is preferable at practical melt spinning processes once glass forming conditions are fulfilled.
The influence of the refilled gas pressure on the glass forming behavior of one of the best ternary glass forming alloys Zr_ (50) Cu_ (40) AI_ (10) was studied for the melt spinning process.The amorphicity of as-quenched ribbons was characterized by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The refilled chamber atmospheric pressure is crucial to the cooling rate of melt spinning. At high vacuum, at pressure less than 0.0001 atm, fully crystalline fragments are obtained. Montolithic amorphous ribbons were only obtained at a gas pressure of 0.1 atm or higher. The extended contact length between thecribbonbons and the copper wheel contributes to the high cooling rate of melt spinning. Hiher chamber gas pressure leads to more turbulence of liquid metal beneath the nozzle; therefore , lower pressure is preferable at practical melt spinning processes once glass forming conditions are fulfilled.