Development of Novel Chromium Alloy Platings by Using Highly Concentrated Aqueous Solutions

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K14446
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26060:Metals production and resources production-related
• Research Institution: Tohoku University
• Principal Investigator: Adachi Ken 東北大学, 多元物質科学研究所, 助教 (10880057)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: クロムめっき / 合金めっき / 濃厚水溶液 / 亜鉛めっき

Outline of Final Research Achievements

With the aim of developing new chromium alloy plating, the electrodeposition behaviour of various metals in concentrated chloride baths was investigated and alloy plating tests were carried out on metal species expected to co-deposit with chromium. The electrode potentials of several metals in concentrated chloride baths were shifted lower than those in dilute baths, and some of them differed significantly from the thermodynamic data of reported complex species. It is suggested that these metal ions exist as unreported complex species. The co-deposition studies focused on the chromium-zinc combination as a metal species capable of co-depositing with chromium. In this system, a metallic film with a stacked structure of alternating chromium and zinc deposits was obtained, which was found to be a unique plating film produced only by this method.

Free Research Field

電気化学

Academic Significance and Societal Importance of the Research Achievements

濃厚塩化物浴における各種金属の電析挙動を系統的に調査することで、金属電析浴としての濃厚水溶液系の利用可能性および有用性を明らかにできた。本研究を足がかりとして、新たな金属めっき素材の開発が進展すると期待される。また、クロム-亜鉛の組み合わせからなる共析膜は、従来法では得られない特異な層状構造を有する。これらの耐腐食性および物性や、共析機構について今後明らかにすることで、合金電析膜の構造と物性の関係に関しても新たな側面を明らかにできる可能性がある。