Preparation And Properties Of Cu-base Cu Based Bulk Metallic Glass

Amorphous alloy compared to crystalline materials exhibit many unique properties such as high strength,good wear resistance and corrosion resistance.Amorphous alloy exhibit viscous flow workability in the supercooled liquid region,and they can be prepared by extrusion molding precision parts.These excellent properties make amorphous alloys become one of the advanced materials.First,we prepare Cu52-xZr48Alx (x=7,8,9,10) alloys through the cooling copper mold suction casting method.The present results sugges that when Al content is less than10%,with the increase of Al element content Cu52-xZr48Alx alloy glass forming ability increases.Cu52-xZr48Alx amorphous alloys exhibit strong heat stability,its reducrd glass transition temperature Trg is more than0.599and y is more than0.409.Compression test confirmed Cu52-xZr48Alx alloy has good mechanical properties,when the Al content is less than10%,the fracture strength of Cu52-xZr48Alx amorphous alloy is basically more than1500MPa,which Cu45Zr4gAl7alloy rupture strength reach2000MPa.Taking CuZrAl alloy as the object,study on the influence of adding rare earth elements Gd、 Y on glass forming ability and mechanical properties of the alloy.The results show that:the amount of rare earth elements Gd and Y doped,the glass forming ability and mechanical properties of Cu47Zr45Al8alloy is improved.And Cu47Zr42Al8Y3and Cu47Zr43Al8Gd2amorphous alloy critical size reached above7mm.Cu47Zr44Al8Yi amorphous alloy rupture strength is2140.8MPa,the elongation rate reached7.17%. In addition,Cu47Zr45Al8alloy prepared by using the high purity of raw materials has stronger glass forming ability.Because the oxygen in low purity raw materials is easy form high melting point oxide,which become the core of heterogeneous nucleation.The crystallization activation energy of alloy was calculated by variable temperature crystallization methods.Low pure raw material preparation of amorphous alloy has larger crystallization activation energy.Therefore the low pure raw material preparation of amorphous alloy has strong thermal stability.While low pure raw material preparation of amorphous alloy has the strong fracture strength.Finally,study the influence of annealing treatment on the microstructure and mechanical properties of Cu43Zr48Al9alloy.Cu43Zr48Al9amorphous alloy occurs structural relaxation、phase separation or crystallization process after isothermal annealing treatment at different temperatures.The temperature of the amorphous alloy precipitation crystallization phase decreases with the extension of annealing time.And with the extension of annealing time,the degree of crystallization of amorphous alloy reinforce.At the same annealing temperature,with the extension of annealing time,the microhardness of the alloy has a tendency to increase.The breaking strength of the amorphous alloy after annealing treatment fell sharply.