Effect of Texture on the <I>r</I>-Value of Cu/18Cr–8Ni–Fe/Ni Clad Metal

Abstract

In order to increase the capacity of miniaturized button-type batteries, the thickness of the Cu/18Cr-8Ni-Fe(SUS304)/Ni clad metals which are applied to the anode cases should be reduced. Therefore it is required that the clad metals have higher strength and excellent drawability. We found that the clad metals had good properties (high tensile strength and small planar anisotropy) which the SUS304 single sheet did not have, as a result of examination of the rolling and annealing process. The texture formation of the clad metals was investigated, and the influence of texture on the r-values is discussed in this research. The SUS304 in the clad metals with good properties has lower Goss and higher brass orientation density than the SUS304 single sheet under the 25% finish rolled condition after annealing. The orientation densities on α- and β-fibers of SUS304 and Cu in the clad metals are qualitatively similar to each other, and different from those of the SUS304 single sheet. This suggests that the characteristic texture of SUS304 in the clad metals is formed through the influence of the Cu layer. The planar anisotropy of r-values was calculated from ODF to inquire into the effect of the texture on r-values by using Taylor's full constraints model and relaxed constraints model. This result corresponded well to the measured r-value, especially in the relaxed constraints model.