Mechanical, corrosion and cavitation erosion properties of LM 9 grade aluminium – multi-walled carbon nanotubes composites

Abstract

ABSTRACT This paper is intended to study mechanical, corrosion and cavitation erosion properties of aluminium metal matrix composites with Multiwalled carbon nanotubes (MWCNTs) as reinforcement. Multi-walled carbon nanotubes in different weight percentages (1, 2 and 3%) are reinforced in Light metal 9 (LM 9) aluminium alloy using the ultrasonic stir casting method. Hardness, pitting corrosion potential and erosion resistance are evaluated to assess the influence of different weight percentages of MWCNTs as reinforcements in LM 9 alloy. The results indicate that Aluminium – MWCNTs composites possess an improved hardness of up to 150 % compared to base LM 9 alloy. The pitting corrosion resistance of composites was found to be excellent with minimum corrosion damage to the composite specimen. Cavitation erosion test performed as per ASTM G32 indicates a decrease in erosion wear for composites reinforced with MWCNTs compared to base material LM 9. The property improvement of the LM 9 – MWCNT composite under dynamic conditions is verified using SEM micrographs. The effect of weight percentage of MWCNTs found to be significant in the enhancement of properties. There are 16 % and 30 % reductions respectively in pitting corrosion potential and erosive wear respectively for composite with 3 % MWCNTs.