Effects of Natural Aging on Age-Hardening Behavior of Cu-Be-Co and Cu-Ti Alloys Severely Deformed by High-Pressure Torsion

Hibino, M.; Watanabe, Chihiro; Tsuji, Y.; Monzen, Ryoichi; Todaka, Yoshikazu; Sato, Wataru

doi:10.2320/matertrans.m2017178

Cited by 6 publications

(4 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Refs. [26,27]. Although difficult to prove unambiguously, a supersaturated solid solution may thus be present directly after HPT deformation.…”

Section: Nanocrystalline Cu-timentioning

confidence: 99%

“…Recent studies on systems forming Guinier-Preston zones (GPZ) [24] and spinodal microstructures [25][26][27][28] offer promise of a solution to this problem. As these decomposition processes occur homogenously and are weakly affected by the presence of defects such as grain boundaries, such features might be retained for the finest grain sizes and so permit better control of the work hardening behavior and ductility of NC metals.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Spinodal Decomposition Stabilizes Plastic Flow in a Nanocrystalline Cu-Ti Alloy

2021

View full text Add to dashboard Cite

“…Refs. [26,27]. Although difficult to prove unambiguously, a supersaturated solid solution may thus be present directly after HPT deformation.…”

Section: Nanocrystalline Cu-timentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Spinodal Decomposition Stabilizes Plastic Flow in a Nanocrystalline Cu-Ti Alloy

2021

View full text Add to dashboard Cite

“…2) The mean grain size of pure Cu processed by the SPD process is 200400 nm 2,3) with tensile strength of ³450 MPa. 3,4) To obtain a finer mean grain size by the SPD process, addition of solute atoms 3) or dispersion of precipitate particles 5) have been demonstrated to effectively suppress the dynamic recovery or recrystallization during the SPD process. Consequently, stronger materials are obtained after the SPD process in solid-solution or precipitation-type alloys with finer grain structures.…”

Section: Introductionmentioning

confidence: 99%

A Comparative Study of Hardness in Nanostructured Cu–Zn, Cu–Si and Cu–Ni Solid-Solution Alloys Processed by Severe Plastic Deformation

Kunimine

Watanabe

2019

Mater. Trans.

View full text Add to dashboard Cite

Although the maximal strength of Cu with a mean grain size of 10 nm has been reported as ³1000 MPa, the maximal strength of nanostructured Cu processed by severe plastic deformation (SPD) is ³450 MPa, owing to the saturation of accumulated strain caused by recovery or recrystallization during the SPD process. The strength of SPD-processed Cu can be increased by adding solid-solution atoms. A significant increase in the strength of nanostructured Cu after adding a small amount of Si solute atoms was reported in our previous study. In this study, various-composition CuZn, CuSi, and CuNi solid-solution alloys were subjected to high-pressure torsion (HPT) processing, which is one of the SPD processes. To reveal the role of solid-solution atoms on the deformation of Cu during the SPD process, the effects of Zn, Si, and Ni additions on hardness and microstructure of Cu after various HPT rotations were systematically investigated, up to the solubility limits of these atoms. It is well known that Zn and Si atoms decrease the stacking fault energy (SFE) of Cu. On the other hand, Ni atoms have the opposite effect to that of Zn and Si on the SFE of Cu. Experimental results were considered in terms of the atomic concentration of solute atoms c a , electron-atom ratio e/a, and the SFE. The hardness of 140 HV of the nanostructured Cu significantly increased with increasing addition of Zn, Si, and Ni. The maximal hardness values of the nanostructured CuZn, CuSi, and CuNi alloys were 250 HV (29.4 at%Zn), 275 HV (4.5 at%Si), and 360 HV (81.4 at%Ni), respectively. In the case of the nanostructured CuZn and CuSi alloys, the hardness increase correlated with the reduction in the SFE as a function of e/a. The decreased SFE by Zn and Si additions increased strain hardening during the SPD process. This strengthened the nanostructured CuZn and CuSi alloys. On the other hand, hardening of the nanostructured CuNi alloys is related not to the SFE changes, but to dislocation pinning or dragging by Ni solute atoms followed by suppression of recovery or recrystallization during the SPD process.

show abstract

“…IACS, 硬度达220 HV. Hibino等人 [7] 利用高压扭转的方式制备了Cu-Co-Be合金并对其进行时效处理, 发现经室温长时间(1个月)时效后, 合金中位错密度、晶粒尺寸等均未发生变化; 可见Cu-Co-Be合金有着强度高、耐自然时效的优异特性. 然而, Cu-Co-Be合金对温度相当敏感, 研究表明Cu-Co-Be合金450℃下显微维氏硬度为室温的80%, 电导率仅为室温的36% [3] .…”

unclassified