Research The Horizontal Continuous Casting Of Cu-Zr-Al Glassy Alloys Plate

Glassy alloy is prepared by means of fast cooling, with an atomic structure of short-range order and long-range disorder. It is a new type of alloy of modern rapid solidification technic that possesses both crystal and amorphous character. Glassy alloy has many good properties, such as, high compression strength, high hardness, excellent wear and corrosion resistance, superplasticity under a certain temperature and good soft magnetic properties, therefore it has good application prospect in biomedical, precision mechanical parts, aerospace, military, and many other fields. However, the preparation conditions of glassy alloys is too critical and low efficiency, so research of alloy compositions with low cost, low critical cooling rate of and high efficient preparation technology has important scientific value and engineering significance.This thesis has been done to design the vacuum horizontal continuous casting equipment of bulk metallic glasses (BMGs) plate and explore the best horizontal continuous casting process. DSC, DTA, metallographic microscope, universal testing machine, vickers hardness tester, scanning electron microscopy (SEM), X-ray diffraction and other experimental equipment analysis have been used to the study thermal physical property parameters, microstructure, mechanical properties of BMGs plate.First of all, the improvement of vacuum horizontal continuous casting equipment has been done, especially on water-cooled copper, graphite flow pass, and insulation crucible to achieve maximum cooling capacity. We studied the alloy smelting process and continuous casting process. Pure metal of Cu, Zr and Al were melted uing electromagnetic induction instead of arc melting alloy to improve efficiency. The influence of heating power and holding period on alloy composition and metallic burning loss rate were studied. We confirmed that the best process was gradually heating and holding 10 min under 1300℃.Then, the glass forming ability with nominal compositions of Cu40Zr50Al10、Cu47Zr4sAl8 and Cu50Zr42Al8 glassy alloys has been investigated. Fully amorphous rods and ribbons were prepared by means of copper mold injection. DTA and DSC tests showed that the three compositions all possessed good glass forming ability. Compositions of Cu40Zr50Al10possessed best glass forming ability with ATx of 89K while glass forming ability of Cu50r42Al8 is relatively weak.We emphasized on the continuous casting process, which included continuous casting rate, withdraw period and pausing period, the initial position of drawing tools, cooling water flow, pouring temperature, casting temperature.. A alloy plate with 6mm × 50 mm × 300mm size had been prepared under the parameters is 1050’Cfor casting temperature,14L/min for cooling water flow,0.5atm for Ar pressure,1mm/s for drawing speed,4s and 4s for withdraw period and pausing period, respectivelyMicrostructure and mechanics properties of Cu40ZrsoAl10 and Cu47Zr45Al8 alloy plate were studied using various experimental testing equipment. We found that both of two plate have amorphous/crystal composite organization. Both Cu40ZrsoAlio and Cu47Zr4sAl8 possessed good compression strength and vickers hardness. However, the microstructure and mechanics properties of Cu^oZrsoAlio alloy plate is better than Cu47Zr4sAl8 alloy plate.