Comparative review of alkaline and acidic etchants in ‎chemical milling

  • Authors

    • Aditya Sandeep More UG Student, Final Year B. Tech.: Manufacturing Science and Engineering, Department of Manufacturing Engineering and Industri-al ‎Management, COEP Technological University (COEP Tech), Chhatrapati Shivajinagar, Pune: 411005, Maharashtra State, India
    • Mayuresh Suresh Desai Research Scholar, Department of Manufacturing Engineering and Industrial Management, ‎COEP Technological University (COEP Tech), Chhatrapati Shivajinagar, Pune: 411005, Maharashtra State, India and Senior Manager - Research and Development, Enpro Industries Private Limited, Markal, Pune: 412105, Maharashtra State, India
    • Sudhir Madhav Patil Associate Professor, Department of Manufacturing Engineering and Industrial Management, ‎COEP Technological University (COEP Tech), Chhatrapati Shivajinagar, Pune: 411005, Maharashtra State, India
    https://doi.org/10.14419/hnceca27

    Received date: April 15, 2025

    Accepted date: May 8, 2025

    Published date: May 11, 2025

  • Acidic Etchants; Alkaline Etchants; Chemical Milling; Etchants; Etching Solution

  • Abstract

    Chemical milling is a widely used material removal process in aerospace, electronics, and automotive manufacturing industries. The ‎selection of an appropriate etchant plays a crucial role in determining process efficiency, surface quality, and overall sustainability. This ‎review examines the comparative performance of alkaline and acidic etchants based on key parameters such as etch rate, precision, material ‎compatibility, waste management, and economic feasibility. The primary objective of this study is to analyze the strengths and limitations of ‎both etchant types to provide insights into optimizing chemical milling processes. A structured review methodology is employed, evaluating ‎existing literature and industrial practices to assess the influence of etchant composition on process outcomes. The analysis highlights that ‎alkaline etchants, such as sodium hydroxide and potassium hydroxide, offer high etch rates but often result in rougher surfaces and greater ‎undercut formation. In contrast, acidic etchants, including ferric chloride and nitric acid, provide superior surface finish, better undercut ‎control, and enhanced precision, making them more suitable for applications requiring fine feature definition. The study also identifies key ‎challenges in chemical milling, such as bath longevity, environmental impact, and waste disposal concerns. Future research directions ‎include the development of eco-friendly etchants, automation-driven process optimization, and hybrid etching techniques to improve efficiency ‎while minimizing environmental impact. The findings of this review contribute to a deeper understanding of chemical milling processes, ‎aiding in the selection of suitable etchants for enhanced precision, cost-effectiveness, and sustainability‎.

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    More, A. S. . ., Desai , M. S. ., & Patil, S. M. (2025). Comparative review of alkaline and acidic etchants in ‎chemical milling. International Journal of Basic and Applied Sciences, 14(1), 264-271. https://doi.org/10.14419/hnceca27