Grain refinement in a Cu–Cr–Zr alloy during multidirectional forging
Grain refinement in a Cu–Cr–Zr alloy during multidirectional forging
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DOI：
10.1016/j.msea.2014.03.116
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发表时间：
2014-06
期刊：
影响因子：
6.4
通讯作者：
I. Shakhova;Z. Yanushkevich;I. Fedorova;A. Belyakov;R. Kaibyshev
中科院分区：
文献类型：
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作者：
I. Shakhova;Z. Yanushkevich;I. Fedorova;A. Belyakov;R. Kaibyshev
研究了Cu-0.3%Cr-0.5%Zr合金在300 K和673 K温度下进行总应变为4的多向锻造时塑性变形过程中的组织变化。变形行为的特点是在早期变形的流动应力迅速增加，随后在大应变的稳态流动。新的超细晶粒的发展是由于应变诱导的小角度晶界的取向差逐渐增加，随着累积应变的增加，小角度晶界通过应变诱导的连续反应演变成大角度晶界，这与连续动态再结晶非常相似。超细晶粒的形成与变形带形成的几何边界密切相关。晶粒细化动力学随变形温度的升高而增加。在673 K时，固溶处理样品和时效样品中尺寸小于2 μm的超细晶粒的面积分数分别为0.36和0.6。而在300 K时，超细晶粒的面积分数不超过0.2.
Structural changes during plastic deformation were studied in a Cu–0.3%Cr–0.5%Zr alloy subjected to multidirectional forging up to a total strain of 4 at the temperatures of 300 K and 673 K. The deformation behavior was characterized by a rapid increase in the flow stress at an early deformation followed by a steady-state flow at large strain. The development of the new ultrafine grains resulted from the progressive increase in the misorientations of the strain-induced low-angle boundaries, which evolve into high-angle boundaries with increasing cumulative strain through a strain-induced continuous reaction that is quite similar to continuous dynamic recrystallization. The formation of ultrafine grains was closely related to the development of geometrically necessary boundaries that is attributed to deformation banding. The grain refinement kinetics increased with an increase in the deformation temperature. At 673 K, the area fractions of the ultrafine grains with a size below 2 μm were 0.36 and 0.6 in the initially solution treated samples and the aged samples, respectively. However, the area fractions of the ultrafine grains did not exceed 0.2 at 300 K.