Abstract
A study on the deformation and fracture behaviors of composites consisting of copper matrix and helical tungsten fibers has been carried out experimentally. Specimens each containing a single tungsten fiber, whose helical angle is varied from 15° to 76°, have been tensile-tested, and the effect of the helical angle on the fracture mode has been studied.
Results obtained show that two types of fracture mode are observed; (I) the fracture ocures in the matrix prior to that at the fiber for the composites reinforced with the helical angles less than 45°, or (II) vice versa for those with the helical angles larger than 53°. The ultimate tensile stress or the fracture stress and the strain at that stress are larger for Type II composites than for Type I composites. Deformation of tungsten fibers in the matrix for Type I composite is elastic, but that for Type II is considerably plastic. When the helical angle is very large, multiple necking and multiple fracture are also observed.
