TITLE:
Fabrication and Investigation of Damping Properties of Nano Particulate Composites
AUTHORS:
K. S. Umashankar, K. V. Gangadharan, Vijay Desai, B. Shivamurthy
KEYWORDS:
Multiwall Carbon Nanotube; LM6; LM25; Damping ratio; Natural frequency;powder metallurgy process.
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.9 No.9,
September
20,
2010
ABSTRACT: Nano particulate composites with Al-Si alloys (LM6 and LM25) as matrix and Multiwall Carbon
Nanotube (MWNT) as reinforcement (0.25, 0.5, 0.75, 1.0 and 1.5 weight percentage) have been
fabricated by powder metallurgy process. Damping specimens were prepared according to
ASTM E 756-05 standard and the specimens were subjected to free vibration test to investigate
the damping ratio and natural frequency. It is observed from the free vibration test data; both
alloys (LM6 and LM25) have shown significant improvement in damping ratio, natural
frequency and modulus when reinforced with 0.5 weight percentage of MWNT. Increase in
weight percentage of MWNT beyond 0.5 leads to deterioration in damping ratio, natural
frequency and modulus. This is due to agglomeration of reinforcement phase. The same has been
observed in the morphological study using transmission electron microscopy (TEM). In this work
an attempt has been made to also investigate the mechanical properties of the fabricated
composites.