Development of the Process for Electroplating with Thick Palladium for the Purpose of Suppression of Metallic Allergy

抑制金属过敏的厚钯电镀工艺的开发

• 批准号: 10650721
• 负责人: HAGI Hideki
• 金额: $ 2.18万
• 依托单位: Fukui University of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650721/
• 关键词: Palladium Plating; Current Efficiency; Eyeglasses Frame; Hydrogen; Diffusion Coefficient of Hydrogen; Hydrogen Concentration; Metallic Allergy; Plating Solution; 水素分解; 電気めっき; ニッケルアレルギー; 拡散係数; パラジウム

A new electrolyte (plating bath) has been developed for palladium electroplating, NHィイD24ィエD2HィイD22ィエD2POィイD24ィエD2 (100kg/mィイD13ィエD1, NHィイD24ィエD2Cl (25kg/mィイD13ィエD1), and pure water (900ml) have been added in the NHィイD24ィエD2OH solution (100ml) constrained PdClィイD22ィエD2 (17g). Palladium was electroplated copper substrates at current densities of 20-200A/mィイD12ィエD1. The current efficiency for palladium deposition was about 95% at 20-30A/mィイD12ィエD1. The plating film at this condition was excellent in luster. The concentration of hydrogen in the palladium electroplated copper specimens was measured by using the heat extraction method, and the palladium plating films were found to contain a large amount of hydrogen. From this result, the inability to obtain thick palladium films is estimated to be the pickup of hydrogen during a plating process, and the deterioration in mechanical properties of the plating film by the hydrogen embrittlement. Then, a relation between the plating condition and the hydrogen concentration was examined. The hydrogen concentration in the plating film did not depend on film thickness. And the concentration was 120mass-ppm at 20A/mィイD12ィエD1 and 20-30mass-ppm at current densities larger than 20A/mィイD12ィエD1.In order to reduce the hydrogen concentration in the plating film, the diffusion coefficient of hydrogen, DィイD2HィエD2 in palladium electroplating films were measured by the electrochemical desorption method. The following has been understood as a result. (1) DィイD2HィエD2 in the palladium plating film was smaller than DィイD2HィエD2 in palladium bulk. (2) DィイD2HィエD2 became large by heat-treating, and DィイD2HィエD2 in the plating films heat-treated at high temperatures was identical with DィイD2HィエD2 in the bulk. (3) The main cause, that DィイD2HィエD2 in the plating films was smaller than that in the bulk, was clarified to be a residual strain in the plating film.

新的电解质(电镀槽)开发电镀钯,NHィイD24ィエD2HィイD22摊位ィエD2POィイD24ィエD2(100公斤/米ィイD13ィエD1, NHィイD24ィエD2Cl(25公斤/米ィイD13ィエD1),并添加了纯水(900毫升)的NHィイD24ィエD2OH解决方案(100毫升)约束PdClィイD22摊位ィエD2(17克)。钯在20-200A/m的电流密度下电镀在铜衬底上。在20-30A/m条件下，钯沉积的电流效率约为95%。在此条件下，镀层具有良好的光泽。用热萃取法测定了镀钯铜试样中氢的浓度，发现镀钯膜中含有大量的氢。根据这一结果，估计不能获得厚的钯膜是由于镀过程中氢的吸收，以及氢脆导致的镀膜力学性能的恶化。然后，考察了镀层条件与氢浓度的关系。镀膜中氢的浓度与膜厚无关。在电流密度大于20A/m的情况下，浓度为120mass-ppm，在电流密度大于20A/m的情况下浓度为20-30mass-ppm。为了降低镀膜中氢的浓度，采用电化学解吸法测定了钯电镀膜中氢的扩散系数D￣D2H￣D2。结果理解如下。(1)镀钯膜中的D￣￣D2H￣￣D2小于钯体中的D￣￣D2H￣￣D2。(2)热处理后的D′′′D2H′′r D2变大，经高温热处理的电镀膜中的D′r D2H′r D2与本体中的D′r D2H′r D2相同。(3)主要原因,DィイD2HィエD2在电镀电影比在批量小,被澄清是在镀薄膜残余应变。