| 摘要 |
The invention concerns a frame for spectacles comprising at least one element made of polycrystalline copper-aluminum-beryllium (Cu-Al-BE) of elasticity between 3 and 6%, preferably of the order of 4%. The polycrystalline alloy composition is 0.5% to 1% of beryllium, 11% to 12% of aluminum, the remainder being copper. The polycrystalline alloy average grain size is less than 0.12 mm. The Cu-Al-BE element is formed by several shrinking operations not exceeding deformation of {fraction (1/100)} th of a millimeter per passage, or 40% of clod shrinking, followed by thermal beta treatment or directly by hot-forming.
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