Young's modulus of sintered iron was measured by a composite piezo-electric quartz oscillator, which is one of the dynamic resonance means. This method gives better accuracy and reproducibility as compared with the mechanical bending test. Specimens (4×4×40 mm) were prepared from a carbonyl iron powder and various commercial iron powders, followed by compacting under 2-9 t/cm2, presintering for 20 min at 650°C and sintering for 0.1-30 hrs, at 800-1200°C in hydrogen.
The results obtained are summarized as follows:
Young's modulus of sintered iron, in general, increases with an increase of the density. Comparing specimens with the same density, Young's modulus of the Carbonyl sintered iron is considerably higher than that of the commercial sintered irons. The reason for this can be attributed to the existence of irregular pores in the commercial one.
Young's moduli of the specimens sintered at austenitic temperature are appreciably higher than those of the specimens with the same density, but sintered at ferritic temperature.