Evidence of refilled chamber gas pressure enhancing cooling rate during melt spinning of a Zr50Cu40A

• 作 者: Hong-wang Yang Peng Zhang M J
• 机 构: School of Materials Science and Engineering,School of Mechanical and Aerospace Engineering
• 出 处: 中国铸造
• 发表日期: 2004年期
• 关键词: metal ic glass amorphous al oy melt spinning glass forming behaviour

The inlfuence of the reifl ed gas pressure on the glass forming behaviour of one of the best ternary glass forming al oys Zr50Cu40Al10 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 reifl ed chamber atmospheric pressure is crucial to the cooling rate of melt spinning. At high vacuum, at pressure less than 0.0001 atm, ful y crystal ine 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 fulifl ed.