Reducing sulfur to improve thermal embrittlement in electrodeposited nickel using citric acid
Reducing sulfur to improve thermal embrittlement in electrodeposited nickel using citric acid
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使用柠檬酸减少硫以改善电沉积镍的热脆性
DOI：
10.1016/j.rsurfi.2020.100001
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发表时间：
2020
影响因子：
--
通讯作者：
Yorinobu Takigawa
中科院分区：
文献类型：
--
作者：
Atsuya Watanabe ;Yorinobu Takigawa
由于在高温下的热脆化，电沉积镍的使用受到限制。电沉积镍通常含有硫，并且硫的晶界偏析导致热脆化。糖精（C7H5NO3S）作为硫的主要来源，被认为是引起热脆化的主要原因.本研究以柠檬酸代替糖精，制备出具有良好延展性及高耐热性的电沉积镍。使用柠檬酸，在宽电流密度范围内获得平行于衬底的强（100）面择优取向，类似于使用糖精的情况。因此，在宽的电流密度范围内，预期从使用柠檬酸的电解质获得的沉积态电沉积物具有高延展性。使用柠檬酸代替糖精钠，样品中的硫含量从0.025重量%显著降低至0.007重量%。即使在300° C下退火24小时，从使用柠檬酸的电解质获得的试样也实现了7.4%的断裂伸长率，而从使用糖精的电解质获得的试样是脆性的，并且在退火状态下没有表现出塑性变形。
Electrodeposited nickel usage has been limited owing to thermal embrittlement at high temperatures. Electrodeposited nickel generally contains sulfur, and the grain boundary segregation of sulfur leads to thermal embrittlement. As the main source of sulfur, saccharin (C 7 H 5 NO 3 S) has been suspected to primarily cause thermal embrittlement. In this study, electrodeposited nickel with improved ductility and high heat resistance was fabricated using citric acid instead of saccharin. Using citric acid, a strong (100) plane-preferred orientation parallel to a substrate was obtained over a wide current density range, similar to the case of using saccharin. Therefore, high ductility is expected in as-deposited electrodeposits obtained from electrolyte using citric acid over a wide current density range. The sulfur content in the samples significantly decreased from 0.025 to 0.007 wt% using citric acid instead of saccharin sodium. Specimens obtained from the electrolyte using citric acid achieved an elongation to failure of 7.4% even when annealed at 300° C for 24 h, whereas specimens obtained from electrolyte using saccharin were brittle and exhibited no plastic deformation at an annealed state.