Microstructural Stability of Copper Electroplate

摘要

Microstructural stability of metals used for high quality optics is necessary to maintain the low light scatter properties of the optical surface. Room temperature recrystallization of metal causes a roughening of the single-point-diamond-turned (SPDT) surfaces and increases the light scatter. Differential scanning calorimetry, microstructure analysis, x-ray diffraction micro-hardness, and mechanical properties data indicates that high internal stresses in the electroplating cause the low temperature recrystallization. Electroplating conditions causing the high stresses and methods of reducing the stresses after plating are discussed. (ERA citation 09:031199)