Zr基块体非晶合金的成分设计及其性能研究

Composition Design and Properties of Zr-based Bulk Amorphous Alloys

根据二元共晶混合法设计Zr-Cu-Ni-Al非晶合金成分,利用铜模吸铸法制备Zr-Cu-Ni-Al合金棒材。采用XRD、DSC、SEM及准静态压缩实验研究了所设计合金的非晶形成能力和力学性能。结果表明:所设计的Zr-Cu-Ni-Al合金均为非晶态结构,其过冷液相区(Δ_(T x))均超过65 K,有较好的非晶形成能力,其中Zr_(55.7)Cu_(22.4)Ni_(7.2)Al_(14.7)合金的Δ_(T x)最宽,达到82 K;合金的塑性变形能力由低到高依次为:Zr_(57)Cu_(18.67)Ni_(8)Al_(16.33)、Zr_(56.36)Cu_(20.53)-Ni_(7.6)Al_(15.51)、Zr_(54.4)Cu_(26.13)Ni_(6.4)Al_(13.07)和Zr_(55.7)Cu_(22.4)Ni_(7.2)Al_(14.7),其中Zr_(55.7)Cu_(22.4)Ni_(7.2)Al_(14.7)的塑性达到5.5%,抗压强度达到1885 MPa,其他三种合金的塑性均不足2%。剪切带的增殖和交互作用与非晶合金的塑性和强度密切相关。合金试样断口中均有熔滴存在,这表明在合金变形过程中,断裂处的合金组织发生了粘性流动,并伴有脉纹产生。合金在塑性变形中均发生了锯齿流变,锯齿流变与自由体积的变化密切相关。

Zr-Cu-Ni-Al amorphous alloy compositions are designed according to binary eutectic mixing method,and are prepared by copper mold suction casting method.XRD,DSC,SEM and quasi-static compression tests were utilized to research the amorphous forming ability and mechanical properties of Zr-Cu-Ni-Al alloys.The results show that the designed Zr-Cu-Ni-Al alloys are completely amorphous structure,and their supercooled liquid region(Δ_(T x))exceeds 65 K,and they have good amorphous forming ability.Among them,Zr_(55.7)Cu_(22.4)Ni_(7.2)Al_(14.7)alloy has the widestΔ_(T x),reaching 82 K.The plastic deformation ability of the alloys from low to high is:Zr_(57)Cu_(18.67)Ni_(8)Al_(16.33),Zr_(56.36)Cu_(20.53)Ni_(7.6)Al_(15.51),Zr_(54.4)-Cu_(26.13)Ni_(6.4)Al_(13.07)and Zr_(55.7)Cu_(22.4)Ni_(7.2)Al_(14.7).The plasticity of Zr_(55.7)Cu_(22.4)Ni_(7.2)Al_(14.7)alloy reaches 5.5%,and the compressive strength reaches 1885 MPa,while the plasticity of the other three alloys is less than 2%.The stronger the initiation and interaction of the shear bands,the higher the plasticity and strength of Zr-Cu-Ni-Al bulk amorphous alloys.There are droplets in the fracture of the alloy samples,which indicates that during the deformation of the alloys,the alloy structure at the fracture has viscous flow,accompanied by the generation of vein patterns.The serration rheology occurs in all alloys during plastic deformation,and the serration rheology is closely related to the change of free volume.