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在脆性的ZrCuNiAl块体合金中添加Nb,获得新型的Zr60.59Cu15.78Ni10.73Al10.75Nb2.15非晶合金。通过XRD、DSC及HRTEM对合金的结构及热力学参数进行测定,并采用静态压缩实验研究其力学性能。结果表明:合金在XRD和DSC精度范围内呈现非晶态特征,但HRTEM结果显示其析出少量1~2nm的纳米晶。Nb的添加还显著降低了合金的结晶激活能,有利于形变过程中纳米晶的进一步形核。纳米晶的存在增加了剪切带的形核位置,阻碍和钝化剪切带扩展,并诱发剪切带分叉及新剪切带形成,提高了合金的室温塑性。该块体非晶的屈服强度为1850MPa,平均塑性应变为11.95%,最大塑性应变达到25.37%,最小塑性应变为2.95%,并具有应变硬化现象。
Nb is added into the brittle ZrCuNiAl bulk alloy to obtain a novel Zr60.59Cu15.78Ni10.73Al10.75Nb2.15 amorphous alloy. The structure and thermodynamic parameters of the alloy were determined by XRD, DSC and HRTEM. The mechanical properties of the alloy were studied by static compression test. The results show that the alloy exhibits amorphous characteristics in the range of XRD and DSC accuracy. However, HRTEM results show that a small amount of nanocrystals with 1 ~ 2 nm are precipitated. The addition of Nb also significantly reduces the crystallization activation energy of the alloy, which facilitates the further nucleation of the nanocrystal during the deformation. The presence of nanocrystals increases the nucleation sites of the shear bands, hinders and blunts the growth of the shear bands, induces the formation of bifurcation of the shear bands and formation of new shear bands, and improves the room temperature plasticity of the alloy. The bulk amorphous yield strength of 1850MPa, the average plastic strain of 11.95%, the maximum plastic strain of 25.37%, the minimum plastic strain of 2.95%, and with strain hardening phenomenon.