Morphology and strain rate effects on heat generation during the plastic deformation of polyethylene/carbon black nanocomposites

The phenomenon of internal heat generation during the plastic deformation of polyethylene/carbon black nanocomposites at high strain rates was investigated using a high resolution thermal camera. Material morphology, strain rate and carbon black (CB) content were found to be critical factors that affected heat generation during tensile testing, and consequently changed the mechanical behaviour. Two processing methods (M1 and M2) were used to prepare the materials, with CB contents of 0.5, 1 and 3 wt.%. The results showed a significant increase in internal heat generation after yielding, with temperatures exceeding 70 °C for materials processed using M1 and 55 °C for materials processed using M2. The temperature increase was dependent on the processing method, the CB content and the strain rate. The increase in temperature due to plastic heat generation affected the properties of the material, reducing the plastic hardening and reducing the tensile strength at high strain rates. This is of significance when considering the use of these materials in applications involving high strain rates, such as impact protection.