Green micromachining of ceramics using tungsten carbide micro-endmills

Journal Article · Wed May 01 00:00:00 EDT 2019 · Journal of Materials Processing Technology

DOI:https://doi.org/10.1016/j.jmatprotec.2018.12.009· OSTI ID:1569820

Onler, Recep ^[1]; Korkmaz, Emrullah ^[1]; Kate, Kunal ^[2]; Chinn, Richard E. ^[3]; Atre, Sundar V. ^[4]; Ozdoganlar, O. Burak ^[5]

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1. Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Mechanical Engineering
2. Univ. of Louisville, KY (United States). Dept. of Mechanical Engineering
3. National Energy Technology Lab. (NETL), Albany, OR (United States)
4. Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Materials Science and Engineering
5. Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Biomedical Engineering

This paper presents an experimental analysis on micromachining of green-state silicon carbide (SiC) and aluminum nitride (AlN) using uncoated tungsten carbide (WC) micro-endmills. Although the unique properties of ceramics make them ideal materials for many applications involving micro-scale features, the industrial adaptation of ceramics at the micro-scale has been hindered due to the lack of viable ceramic micro-manufacturing techniques. Green micromachining (GMM), where micro-scale features are created by micromachining green-state ceramics that contain ceramic particles and a polymer binder, offers a potential solution for this problem by affording tremendous improvements in micromachinability with respect to sintered ceramics. After the completion of GMM, the green parts are debound and sintered to obtain the final component with the desired microscale features. In this work, we evaluated GMM characteristics of powder-injection molded green-state SiC and AlN to correlate process conditions and green-material compositions with the micromachining forces, quality, and tool wear. An experimental study that involves full immersion micromilling tests with 254 μm diameter micro-endmills at different cutting speeds and feed rates is conducted. For each of the two materials, two binder states (with and without wax) and two powder states (with micro particles only, or with both micro- and nanoparticles) are investigated. Green micromachining forces, specific energies and the resulting surface roughness are analyzed quantitatively. A qualitative analysis of burr formation and channel quality, as well as a preliminary study on micro-tool wear are also performed. Both the machining conditions and the material compositions are seen to have a strong effect on micro-machinability of green-state ceramics. Overall, we conclude that GMM can be a viable ceramic micro-manufacturing strategy if favorable (or optimal) micromachining and material parameters are identified through the presented (or a similar) micromachinability study.

• Research Organization: National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV, and Albany, OR (United States)
• Sponsoring Organization: USDOE Office of Fossil Energy (FE)
• OSTI ID: 1569820
• Journal Information: Journal of Materials Processing Technology, Vol. 267, Issue C; ISSN 0924-0136
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE