Creep behaviour of shock wave surface treated aluminium – MWCNT nanocomposites

Abstract

This work focuses on the creep characteristics of shock wave surface treated aluminium nanocomposites for aerospace and defence applications. Aluminium nanocomposites were undergone a surface treatment in shock tube with free piston (STFP) setup condition. The indentation creep study of shock wave surface treated Al – 4.9 Mg alloy (AA5083) reinforced with multi walled carbon nanotubes (MWCNT) nanoparticle with varying weight fraction of MWCNT nanoparticles was tested under two stresses such as 113 MPa and 170 MPa at different temperatures ranges from 473 K to 573 K. The base and nanocomposite materials were developed using a semi-solid state casting method. The instantaneous shock material reaction is characterised by carbide formation of the developed 1.5 wt% and 1.75 wt% nanocomposites. From the obtained results of creep study, shown that the nanocomposites with 1.5 wt% and 1.75 wt% of MWCNT have better creep resistance and stress exponent value at high working temperature compared to base alloy material. The enhanced creep resistance is due to the increased addition of MWCNT nanoparticle into the Al – 4.9 Mg matrix material and nanostructured carbide formation. The attained stress exponent values propose the major creep mechanism in the base alloy and nanocomposite materials was grain boundary sliding.