<100>軸方位銅単結晶の変形挙動

抄録

It is well known that aluminum single crystal having <100> tensile orientation shows initial rapid hardening but after about several per cent elongation, its tensile stress-strain curve becomes very flat until failure. The present authors observed and reported previously that the clustered slip accompanied by prominent cross slips propagates 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 detailed deformation behavior of copper single crystal having <100> tensile orientation still remains unclarified.
In the present study, the <100> oriented copper single crystal was tested in tension at 200, 20 and -196°C in order to clarify the mechanism of deformation. The effects of tensile orientation, stacking fault energy and deformation temperature on the occurrance of prominent cross slips were discussed.
The prominent cross slips have occurred in the <100> oriented copper single crystal and they were observed more frequently with increasing the deformation temperature. However, it was found that the number of prominent cross slips in the copper crystal was much fewer than that in the 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 of stacking fault energies in these two metals.