抄録
Cheap, mass-produced rigid PVC can serve as substitute for metals and its applications as pipes are steadily increasing.
The fatigue strength of rigid PVC pipe under simulated service conditions has been investigated, and the characteristic of its deformation studied by X-ray diffraction. The following results have been found;
(1) Like that of other high polymers, the fatigue strength of rigid PVC depends on the temperature. Its notch-sensitivity under fatigue is affected by its shape and loading stress.
(2) The characteristic of its deformation can be quantitatively evaluated by annealing the material at various temperatures before and after the working, taking note of its diffraction halo every time by exposing the material to the characteristic X-rays, and thereby comparing the changes in diffraction halo corresponding to the changes in the annealing temperature.
Through microstructure investigation of tensile deformation and fatigue deformation by this method, it has been confirmed that these deformations, just like those in metals, have different characteristics.
