Chair of Materials Science and Methods, Saarland University, 66123 Saarbrücken, Germany.
Department of Metallurgical Engineering, Institute Technology of Bandung, Bandung 40132, Indonesia.
Molecules. 2020 Nov 8;25(21):5194. doi: 10.3390/molecules25215194.
Strategies to improve tensile strength and ductility of pulsed electrodeposited nanocrystalline Co-Cu were investigated. Parameters of deposition, which are pulse current density, duty cycle, and pulse-on time were adjusted to produce nanocrystalline Co-Cu deposits with different microstructures and morphologies. The most significant improvement of strength and ductility was observed at nanocrystalline Co-Cu deposited, at a low duty cycle (10%) and a low pulse-on time (0.3 ms), with a high pulse current density (1000 A/m). Enhancement of ductility of nanocrystalline Co-Cu was also obtained through annealing at 200 °C, while annealing at 300 °C leads to strengthening of materials with reduction of ductility. In the as deposited state, tensile strength and ductility of nanocrystalline Co-Cu is strongly influenced by several factors such as concentration of Cu, grain size, and processing flaws (e.g., crystal growth border, porosity, and internal stresses), which can be controlled by adjusting the parameters of deposition. In addition, the presence of various microstructural features (e.g., spinodal and phase decomposition), as well as recovery processes induced by annealing treatments, also have a significant contribution to the tensile strength and ductility.
研究了提高脉冲电沉积纳米晶 Co-Cu 拉伸强度和延展性的策略。通过调整沉积参数，即脉冲电流密度、占空比和脉冲持续时间，制备出具有不同微观结构和形貌的纳米晶 Co-Cu 沉积物。在低占空比（10%）和低脉冲持续时间（0.3 ms）、高脉冲电流密度（1000 A/m）下沉积的纳米晶 Co-Cu 具有最佳的强度和延展性改善效果。在 200°C 退火也可以提高纳米晶 Co-Cu 的延展性，而在 300°C 退火则会导致材料强化，同时延展性降低。在沉积状态下，纳米晶 Co-Cu 的拉伸强度和延展性受到多种因素的影响，如 Cu 浓度、晶粒尺寸和加工缺陷（如晶体生长边界、孔隙和内应力），这些因素可以通过调整沉积参数来控制。此外，各种微观结构特征（如spinodal 和相分解）的存在以及退火处理引起的回复过程，也对拉伸强度和延展性有显著的贡献。
