抄録
It is well known that an aluminum single crystal having a ⟨100⟩ tensile orientation shows initially rapid hardening and subsequently, after about several per cent elongation, the tensile stress-strain curve becomes very flat until failure. It was reported by the present authors that propagation of clustered slip accompanied by prominent cross slip was observed in this flat region of the curve. Similar stress-strain curves were reported in the ⟨100⟩ oriented gold and silver single crystals deformed at room and high temperatures, respectively. However, the details of deformation behavior of copper single crystals having a ⟨100⟩ tensile orientation still remain unclear.
In the present study, the ⟨100⟩ oriented copper single crystals were tested in tension at 473, 293 and 77 K in order to clarify the mechanisms of deformation. The effects of tensile orientation and deformation temperature on the occurrence of prominent cross slip were studied.
Prominent cross slip occurred in the ⟨100⟩ oriented copper single crystals and was observed more frequently with increasing deformation temperature. However, it was found that the frequency of prominent cross slipping in the copper crystal was much fewer than that in aluminum crystal, and the flat region of the stress-strain curve was not observed. The difference in deformation behavior between copper and aluminum crystals is considered to be due to the difference in stacking fault energy between these two metals.
