Effects of reinforcement percentages in AWJM of zirconia coated MWCNTs reinforced HDPE composites

This study investigates the effects of abrasive water jet machining parameters on plain HDPE specimens and zirconia-coated multiwall carbon nanotube (ZrO₂-MWNT) HDPE composite specimens. In this experiment, 1–4 wt.% of zirconia-coated multiwall carbon nanotubes were added to the HDPE matrix. The results indicate that water pressure significantly impacts surface roughness in neat HDPE, while stand-off distance shows increased influence in reinforced HDPE composites, likely due to altered jet-material interaction from hard-phase reinforcements. This sequence of influences is observed in both cases. Furthermore, in each trial of machining, the surface roughness of neat HDPE is less than the roughness of zirconia-coated multiwall carbon nanotube reinforced HDPE. The experimentation results confirmed that as the percentage of the zirconia-coated multiwall carbon nanotubes increases, there is an increment in the hardness of the material and in roughness values, which signifies that the addition of reinforcement significantly affects surface roughness.