Tribological behaviour of 1D and 2D nanofiller based high densitypoly-ethylene hybrid nanocomposites: A run-in and steady state phase analysis

Abstract

Hybrid nanocomposites are a class of materials with exceptional properties due to the synergizing effect of individual fillers. Current work reports the tribological behaviour of high densitypolyethylene-(HDPE) reinforced with 1D-(Multi walled carbon nanotubes-(MWCNTs) and 2D-(h-Boron Nitride nanoplatelets-(BNNP) nanofillers. MWCNTs and BNNPs are chemically modified prior to solution deposition on HDPE and then processed through injection moulding. Testing was performed by varying Load, Speed and Sliding distance for all samples. Parameters such as wear volume, static and kinetic friction co-efficient, surface roughness in steady state and run-in phases, hardness, plasticity index and thermal expansion coefficient were reported. The wear volume of 0.1BNNP composite has shown reduced values as compared to 0.1MWCNTfor all parameters of testing. Highest wear resistance is exhibited by HDPE/0.25MWCNT/0.15BNNP hybrid nanocomposite. Plasticity index was reduced by 40% for HDPE/0.25MWCNT/0.15BNNP sample. The surface roughness increased with speed and sliding distance, while reduced with increasing load. Static and kinetic friction coefficients were also estimated. The surface morphology was examined at the end of Run-in and Steady state to identify prominent wear mechanisms. It is concluded that BNNP based composites possess better properties compared to MWCNT for equal loading, however, Hybrid composites of 1D/2D nanofillers has been shown superior properties.