A Study of the Effect of Scratch on the Mechanical Property of Injection Molded Polymer and Glass Fiber Composite

Abstract

The scratch behavior of polymer materials and corresponded reinforced composites have raised significant concern and attention, due to their widely applications such as automotive interior parts and household products where surface’s high quality and durability are demanded. As well known that scratch damage of material is complex and also attributed to various parameters such as scratch conditions (scratch load, velocity, and scratch tip geometry/size) and material’s properties (modulus, strength, coefficient of friction and indented hardness), which accelerates critical fracture existence and evolution in following mechanical testing process. In this paper, various scratch patterns were introduced for injection molded neat polycarbonate (PC), and 20wt% of glass fiber (GF) additive corresponding GF/PC dumbbell sample and plates. Initially, critical scratch depth in dumbbell sample’s thickness direction for respective material was investigated. Afterwards, all kinds of plate materials with corresponded critical scratch depth were employed for plate bending test with impact striker under static loading. Finally, impact damage tolerance of scratched injection molded plates was discussed based on impact energy absorption, related observation of damage development and formed fractural appearance. The results indicates that scratch effect must be taken into consideration when estimate composite material’s mechanical property