Proceedings of the
9th International Conference of Asian Society for Precision Engineering and Nanotechnology (ASPEN2022)
15 – 18 November 2022, Singapore

Factoring Surface Area for Mechanochemical Effects During Micro-scratching

Lionel Yan Jin Lee, Jianyu Tu, and Hao Wanga

Department of Mechanical Engineering, College of Design and Engineering, National University of Singapore, 9 Engineering Drive 1, 117575, Singapore


The mechanochemical effect is beneficial to the micro-cutting process but the working mechanism and the condition for its manifestation is far from understood. This work focuses on the surface area for chemisorption to occur under the application of a surface-active medium (SAM). 0.1 µm deep nano-grooves were produced to increase the surface area of rapidly solidified aluminum (RSA6061). After which, a SAM was applied, and constant load micro-scratching tests were performed perpendicular to the nano-grooves. The manifestation of the mechanochemical effect was identified by the difference in penetration depth, which was reduced by up to 63.2% corresponding to a 18.2% increase in scratch hardness. The magnitude of the mechanochemical effect was determined by analyzing the residual depth where a progressive increase was observed with the increase in surface area over a range of 16.4-39.9%. Changes in the elastic recovery were also observed with a lower degree of recovery under chemisorption. However, the rate of increase in mechanochemical effect manifestation was not linearly dependent on the surface area, which suggests that additional geometrical factors such as the shape of the nano-grooves may also be important for consideration in understanding the conditions to support the mechanochemical effect during micro-cutting.

Keywords: Micro-scratching, Aluminum alloy, Mechanochemical effect, Chemisorption, Micro-cutting

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