Abstract
The sintered iron compacts generally have many pores. The author investigated how the amount and shape of pores affect the fatigue fracture of sintered iron compacts and observed microscopically the aspects of its fatigue fracture under low cycle.
The following conclusions are obtained from the above microscopical observations.
1) Firstly slip bands generate in grains and they grow into fatigue crack, and the crack appeared to propagate from pore to pore through in grain or along grain boundary.
2) Fatigue cracks generate from all pores. But, fatigue crack grows generally from medium or fine pores and scarcely from larger pores.
