Damping capacity of friction stir processed commercial pure aluminium metal. (2020)

• Record Type: Journal Article
• Authors: Venkateswara Reddy, K.; Bheekya Naik, R.; Madhusudhan Reddy, G.; Arockia Kumar, R.
• Is Part Of: Materials today. Volume 27:Part 3(2020)
• Page Start: 2061
• Page End: 2065
• Publication Date: 2020
• Subjects: Friction stir processing (FSP) -- Hardness -- Damping capacity -- Dynamic mechanical analyser (DMA) -- Pure aluminium; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2019.09.059
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: The metallic materials are generally poor dampers of vibration as compared to polymeric materials. However, microstructure refinement was shown to be effective in enhancing the damping properties of metallic materials. In this study, the microstructure of commercial pure (CP) aluminium has been refined using friction stir processing (FSP) further its vibration-damping properties are evaluated using the dynamic mechanical analyser. The CP-aluminium was friction stir processed at 600 rpm and 60 mm/min to achieve fine microstructure. Electron backscattered diffraction (EBSD) and XRD analysis were employed to measure grain size and dislocation density of processed samples, respectively. The stir zone of processed specimens consists of fine and fully recrystallized grains. The results showed that the average grain size is approximately 10 µm after FSP. The hardness of the Al is decreased by 27% after FSP. The damping capacity was studied by the dynamic mechanical analyser (DMA) applying three-point bending mode. The damping capacity of processed specimens at room temperature was measured to be lesser than the as-received specimen. While increasing the temperature, beyond 130 °C, the damping capacity of processed specimens was measured to be better than the as-received sample. The decrease in damping capacity of processed samples at room temperature is due to the reduction of dislocation density while an increase of damping at high temperatures due to an increase in the grain boundary area.