Abstract
The deformation and rupture behavior of tensile specimens of iron compact were observed on the polished surface, on the sectional area and on the fracture surface.
On the polished surface, cracks developed into a network structure. But most of these cracks did not propagate into the specimens, and remained as grooves within a thin surface layer.
In highly sintered specimens, pores expanded and coalesced as observed in the case of the usual ductile fracture of cast materials, in other words, internal necking took place.
In lightly sintered specimens, welded necks at the particle boundaries were broken, and the particles themselves were not deformed. Though, this type of fracture appeared to be brittle by light microscopy, it was recognized to be ductile by a detailed observation through a scanning electron microscope.
The surface cracking and the internal necking were considered to be due to less constraint on the free surface than in the interior.
