Research On Horizontal Continuous Fabrication Of Bulk Metallic Glasses

Bulk metallic glass is a new-type alloy materials which can be fabricated by conventional casting methods instead of rapid solidification methods. Because of the excellent mechanical properties such as high strength, high hardness, high corrosion resistance and large elastic strain, bulk metallic glasses has been expected to be used in wide application field. Despite the excellent mechanical properties of bulk metallic glass, however, there are several drawbacks that prevent their widespread commercialization and application. The most important draw is that the size and shape of bulk amorphous alloy products are quite limited since the only commercially available process for their fabrication is die-casting. There are few casting methods available which can continuously produce products of bulk metallic glass on a commercial scale. So it is believed that continuous fabrication method can be a viable fabrication process for the continuous fabrication of bulk amorphous alloy rods, which has advantages of cost-effective and high-productivity rather than conventional metal mold casting. Considering that horizontal continuous fabrication method is a quite high efficient process, it might result in the acceleration of the bulk metallic glass in the industrial application.This paper aims to design the proper parameters to fabricate Zr55Cu30Ni5Al10bulky glass rod by horizontal continuous fabrication method, consider the formation mechanism for the bulk metallic glass in the continuous solidification processing and the effects of processing parameters on inner microstructure of the rod.Feasibility of HCC method for fabrication bulk metallic glass rods has been verified in this paper. For consider the effects of drawing rates on inner microstructure of the rod, we systematically investigated the effects of drawing rate on the continuous solidification process of the melt alloy. The results indicated that the microstructures of Zr55Cu30Ni5Al10rods are closed affected by the drawing rate. Controlling the proper drawing rate is significant to fabricate Zr55Cu30Ni5Al10glassy rod.For consider the effects of casting temperatures on inner microstructure of the rod we systematically investigated the effects of temperature on the continuous solidification process of the melt alloy. The results indicated that the microstructures of Zr55Cu30Ni5Al10rods are closed affected by the drawing rate. Controlling the casting temperature is significant to fabricate Zr55Cu30Ni5Al10glassy rod. The Zr55Cu30Ni5Al10glassy alloy rod with a diameter of10mm and tens of centimeters for length has been produced by HCC with proper processing parameter. The processing parameter is that:1253K,7L/min, and drawing5s at2mm/s and stopping2s in the water-cooled mould.The DSC curves and the DTA curves of the Zr55Cu30Ni5Al10glassy alloy rod show thermophysical property of the glassy sample. The supercooled liquid region exceeding85K, indicating that this alloy has high thermal stability of the supercooled liquid as well as high glass-forming ability.For consider the effects of glassy character on mechanical property, we systematically investigated the mechanical property of the Zr55Cu30Ni5Al10sample with different microstructure. It was found that the existence of the crystalline structure is quite harmful to the mechanical properties of the Zr55Cu30Ni5Al10rod.