Furukawa Electric Review No.47 Fusion of Core TechnologiesCrystal Orientation Distribution and Elastic Anisotropy in Cu-Ni-Si Alloy Sheets

Hiroshi Kaneko, Tatsuhiko Eguchi, Hirofumi Inoue

The authors researched the influence of crystal orientation distributions in precipitation- hardened Cu-Ni-Si alloy sheets for springs on their elastic anisotropy. The crystal orientation distributions were measured by the X-ray pole figure measurement and the Electron Backscatter Diffraction (EBSD) method, and the Young’s moduli were measured by the resonance method and the tensile method at various composition ratios of several crystal orientations which developed during recrystallization. The Young’s modulus was the lowest when the Cube orientation{001}<100> was developed and the highest when the R orientation{ 231}<346> was developed. The difference was 30 GPa and above, and showed a good correspondence to the Hill model based on the crystal orientation distribution function (ODF). Different from the existing method of controlling the Young’s modulus by the increase of solution elements, this effect can broaden the variation of Young’s modulus without losing a good electrical conductivity. Therefore, this effect greatly enhances the flexibility of the design of springs for electric contact sections and contributes to the advancement in operations of connectors.