Sv. Nair et al., FRACTURE-RESISTANCE OF POLYBLENDS AND POLYBLEND MATRIX COMPOSITES .1.UNREINFORCED AND FIBER-REINFORCED NYLON 6,6 ABS POLYBLENDS/, Journal of Materials Science, 32(20), 1997, pp. 5335-5346
The deformation behaviour and the fracture resistance of a range of ny
lon 6,6/ABS alloys of varying composition both with and without the pr
esence of glass fibres were investigated. The deformation behaviour wa
s characterized by careful measurements of the volumetric strain durin
g tensile tests in order to understand the relative roles of cavitatio
n and shear yielding in these materials. The fracture resistance was i
nvestigated in detail in the fracture mechanics sense by characterizin
g the J-integral fracture initiation toughness. In materials exhibitin
g stable crack growth, a new parameter, namely, the plateau value of t
he J-integral fracture resistance curve, was measured directly and rep
resented the resistance of the material to stable crack growth. The re
sults showed that the relationship between the deformation behaviour a
nd fracture resistance was related to the extent of damage that develo
ped in the crack-tip zone. Substantial additional toughening was devel
oped during the crack extension stage both in the presence a nd absenc
e of glass fibres. Glass fibres were found to promote shear yielding a
nd, as a result, enhance both the fracture initiation as well as the f
racture propagation resistance of the nylon 6,6/ABS alloys.