Effect of fiber content and orientation on the scratch behavior of short glass fiber reinforced PBT composites

To investigate the scratch behavior of short glass fiber (SGF) reinforced polybutylene terephthalate (PBT) composites, the scratch tests with the progressively increasing normal load were conducted for PBT reinforced with 0 wt%, 10 wt%, 20 wt% and 30 wt% SGF. The effect of fiber content and orientation on the scratch behavior of PBT composites and underlying scratch damage mechanisms were investigated. The addition of SGF alters the critical normal loads of onset fish-scale deformation and material removal respectively. The glass fiber fracture was observed and its damage mechanism was analyzed. The results show that although the bulk mechanical properties of PBT are enhanced, the addition of glass fiber generally causes poor scratch resistance. The guidance for designing scratch-resistant SGF reinforced PBT is also discussed.