Zr_(61)Ti_(2)Cu_(25)Al_(12)非晶态合金在四点弯曲加载模式下的弯曲弹性极限

Flexural elastic limit of Zr_(61)Ti_(2)Cu_(25)Al_(12)amorphous alloy under four-point bending loading mode

按照当前金属材料弯曲性能测试标准中推荐的跨厚比设计Zr_(61)Ti_(2)Cu_(25)Al_(12)非晶态合金的弯曲试验,试样将发生大挠度弹性变形。经过推导证明,弯曲试样不发生大挠度弹性变形的跨厚比上限取决于材料的弹性应变极限,锆基非晶态合金的弹性应变极限为2%,在四点1/4弯曲模式下不发生大挠度弹性变形的跨厚比上限值为22。在保证小挠度变形的前提下,通过四点弯曲循环加载-卸载试验,Zr_(61)Ti_(2)Cu_(25)Al_(12)合金试样最外表层发生初始剪切变形所对应的弯曲屈服应力约为1760 MPa,产生0.01%残余应变所对应的弯曲弹性极限σ_(p0.01)为2040 MPa。

The bending test of Zr_(61)Ti_(2)Cu_(25)Al_(12)amorphous alloy was designed according to the span-thickness ratio recommended in the current metal material bending performance test standard,and the specimen would undergo large deflection elastic deformation.It was proved that the upper limit of the span-to-thickness ratio of the bending specimen without large deflection elastic deformation depended on the elastic strain limit of the material.The elastic strain limit of the zirconium-based amorphous alloy was 2%,and the upper limit of the span-to-thickness ratio without large deflection elastic deformation in the four-point 1/4 bending mode was 22.Under the premise of ensuring small deflection deformation,through the four-point bending cyclic loading and unloading test,the bending yield stress corresponding to the initial shear deformation of the outermost surface of the Zr_(61)Ti_(2)Cu_(25)Al_(12)alloy sample was about 1760 MPa,and the bending elastic limitσ_(p0.01)corresponding to 0.01%residual strain was 2040 MPa.