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采用“二元共晶混合”法设计富Cu基Cu-Ti-Ni-Zr合金成分,通过水冷铜模铸造法制备出不同直径Cu-Ti-Ni-Zr合金棒材。利用X射线衍射仪(XRD)、差示扫描量热仪(DSC)、万能试验机和扫描电镜(SEM)研究合金的玻璃形成能力和力学性能。结果表明,Cu_(49.64)Ti_(35.08)Ni_(7.69)Zr_(7.6)合金具有较高玻璃形成能力,其临界直径可达4 mm;而表征玻璃形成能力的热力学参数过冷液相区ΔTx和参数γ值最小,分别为26 K和0.385;另外,约化玻璃转变温度Trg值却与临界直径小于3 mm的Cu_(51.1)Ti_(34.1)Ni_(7.2)Zr_(7.6)合金的Trg值相等。通过对合金力学性能进行研究,结果表明,Cu_(49.64)Ti_(35.08)Ni_(7.69)Zr_(7.6)和Cu_(51.1)Ti_(34.1)Ni_(7.2)Zr_(7.6)非晶合金分别具有0.75%和0.28%的塑性,而Cu_(48.18)Ti_(36.06)Ni_(8.16)Zr_(7.6)非晶合金断裂机制近似为脆性断裂。通过锯齿流变应力降分析,发现剪切带稳定扩展应力降大于剪切带萌生或缓慢扩展时应力降,且塑性较好的剪切带萌生应力降约大于近似脆性材料剪切带萌生应力降,而剪切带萌生应力降小于5 MPa。
The Cu-based Cu-Ti-Ni-Zr alloy was designed by using “binary eutectic mixing” method, and Cu-Ti-Ni-Zr alloy rods with different diameters were prepared by water-cooled copper mold casting. The glass formation and mechanical properties of the alloys were investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), universal testing machine and scanning electron microscope (SEM). The results show that the critical diameter of Cu 49.64 Ti 35.08 Ni 7.69 Zr 7.6 alloy is higher than that of the glass, and the critical diameter is up to 4 mm. The thermodynamic parameters ΔTx The values of γ were the smallest, 26 K and 0.385, respectively. In addition, the Trg value of the reduced glass transition temperature was equal to the Trg value of Cu 51.1 Ti 34.1 Ni 7.2 Zr 7.6 alloy with the critical diameter less than 3 mm . The results show that the mechanical properties of Cu 49.64 Ti 35.08 Ni 7.69 Zr 7.6 and Cu 51.1 Ti 34.1 Ni 7.2 Zr 7.6 alloy have the properties of 0.75 % And 0.28%, respectively. However, the fracture mechanism of Cu_ (48.18) Ti_ (36.06) Ni_ (8.16) Zr_ (7.6) amorphous alloy is approximately brittle fracture. Through the analysis of the stress drop in the sawtooth, it is found that the stress drop of the shear band is larger than the stress drop of the shear band when the shear band is sprouting or slowly expanding, and the plastic stress drop of the shear band is larger than that of the approximate brittle material , While the shear stress of initiation is less than 5 MPa.