Optics+Photonics 2016: Precision SiC polishers win Kingslake Award

02 Sep 2016

Paper from PLA University of Science & Technology and Research Center for Ultraprecision at Osaka University recognized.

At this week’s event in San Diego, A paper from researchers at PLA University of Science and Technology and the Research Center for Ultraprecision Science and Technology of Osaka University outlining a sophisticated process for the polishing and finishing of reaction-sintered silicon carbide was awarded the Rudolf Kingslake Medal and Prize for 2015.

The award is presented annually to the most notable original paper published in Optical Engineering, by SPIE, the international society for optics and photonics.

Three researchers from PLA University of Science and Technology and two from the Research Center for Ultraprecision Science and Technology of Osaka University are the recipients of the Rudolf Kingslake Medal and Prize for 2015. The award is presented annually to the most noteworthy original paper published in Optical Engineering, by SPIE, the international society for optics and photonics.

Xinmin Shen, Qunzhang Tu, Guoliang Jiang, Hui Deng, and Kazuya Yamamura are the authors of the winning paper, Mechanism analysis on finishing of reaction-sintered silicon carbide by combination of water vapor plasma oxidation and ceria slurry polishing. It was published in the May 2015 issue of the journal.

Reaction-sintered silicon carbide (RS-SiC) has robust mechanical, chemical, and thermal properties, making it ideal for applications in space telescope systems and as ceramic material used for molds of glass lenses. Some of these properties include a low thermal expansion coefficient, high thermal conductivity, high radiation resistance, high specific stiffness, and impressive bending strength.

Due to the compound’s high level of hardness and chemical inertness, researchers have run into a few challenges including the removal of RS-SiC post-application, which is very difficult using traditional mechanical and chemical techniques.

Two-step process

Smoothing and finishing of a RS-SiC surface has also proved to be a difficult task. The most promising and effective method so far involves a two-step process of water vapor plasma surface oxidation for 90 minutes shown in the paper’s Fig. 3(a), followed by 40 minutes of ceria slurry polishing on the oxidized layer shown in (b). Once an ultra-smooth surface has been achieved, the compound can be further developed and/or promoted for application in the fields of optics and ceramics.

The proposed technique is “a low-cost, efficient, and simple process, and the oxide layer is easy to machine, which can be an attractive technique for the machining of RS-SiC, RB-SiC, HP-SiC, and other SiC products by further development,” say the authors.