Abstract
This paper presents experimental results for the deformation properties of injection-molded glass fiber/polyamide 66 composites. A weighed amount of glass fibers was mixed with polyamide 66 using a twin extruder and the amount of glass fibers was varied from 17 to 41 vol%. Tensile tests were performed on flat tensile specimens. Specimens (C specimens) were prepared by cutting injection-molded plates in three different directions: parallel to the flow direction, normal to the flow direction, and 45° to the flow direction. Injection-molded specimens (M specimens) were also used. The effects of the specimen orientation and fiber volume fraction on the tensile properties were investigated. In addition, dynamic viscoelastic tests were performed and the effect of fiber orientation on the temperature dependence of the storage and loss moduli of skin and core layers of the composites was investigated. To correlate with the tensile properties, the microstructure of the fracture surfaces of the composites was examined by a scanning electron microscope (SEM). The Young’s modulus increased as the fiber volume fraction was increased from 17 to 41 vol%, but the maximum tensile strength was achieved at a fiber volume fraction of 27 vol%. For the same fiber volume fraction, the Young’s modulus and tensile strength of the 0° specimen were higher than those of the 45°and 90° specimens.
