Study Of Preparation And Some Properties Of Bulk Amorphous Alloy Cuzrti Department

Multi-component Cu-Zr-Ti-based bulk metallic glassy(BMG) alloys were prepared by means of copper-mold vacuum suction casting. The glassy structure, thermal stability, glass-forming ability(GFA) and mechanical properties of these alloys with nominal composition of Cu₆0-xZr₃0Ti₁0M_x, Cu₆0-xZr₂0Ti₂0M_x(M=Mg, Mo, Mn, Sn or Al) were investigated by differential scanning calorimeter(DSC), X-ray diffraction(XRD), scanning electron microscope(SEM), Vicker's hardness and compression tests. The GFA and some properties were also analyzed by alloying elements addition. The results obtained are summarized as follows.l)The GFA of Cu-Zr-Ti-based BMG alloys were analyzed by alloying elements addition, such as with elements of different families or different periods in the periodic table, and with increasing alloying elements content.As we all know, Cu₆0Zr₃0Ti₁0 BMG alloy can be prepared with 3 4mm diameter, Cu₅8Zr₃0Ti₁0M₂(M=Mg,Mo,Al and Sn) alloys have been prepared with 3mm diameter by Mg, Al and Sn addition and with 2mm diameter by Mo addition. However it is difficult to prepare full BMG alloys with 3mm diameter by increasing the alloying elements to 3at.%.Amorphous ribbon Cu₆0Zr₂0Ti₂0 can only be prepared as reported, but in this work, Cu₅8Zr₂0Ti₂0Mo₂ BMG alloy with 3mm diameter has been prepared successfully by Mo addition, and Cu₅7Zr₂0Ti₂0Mo₃ metallic glassy alloy with 3mm diameter contains some crystal phase. It is difficult to prepare BMG alloys with 3mm diameter by decreasing Mo content to 1 at.% or increasing to 4 at.%.2) Thermal stability was examined by DSC at heating rate of 20°C/min. In the Cu₆0-xZr₃0Ti₁0M_x(M=Mg, Mo, Al and Sn) system, all BMG alloys exhibit crystallization through two main exothermic peaks, the values of glass transition temperature(Tg) are above 420℃, and the values of thermal parameter change slightly by Mg, Mo and Al addition. But by Sn addition, the values of glass transition temperature (Tg), the onset temperature of crystallization(Tx) and the first crystallization peak temperature(Tpl) increase and the supercooled liquid region(ATx) for Cu₅9Zr₃0Ti₁0Sn₁ BMG alloy increases from 41.2℃ to 53.3℃. BMG alloy shows similar crystallization behavior through two main...