The Relationship between Mechanical Properties and the Dispersion of Precipitates in Nickel-Aluminium Bronze

Abstract

The influence of the spacing between particles on the mechanical properties, especially on the fatigue strength, was summarily investigated by using dispersion-strengthened nickel-aluminium bronzes which had a constant quantity of precipitates. The cast specimens made from high purity materials were quenched in water from the temperature of 1000°C and then aged at 650°C from 15 to 1000 hours to obtain 6 specimen of alloys which had different mean spacings under the condition of a constant quantity of precipitates. The following results were obtained: (1) The fatigue strength of an alloy which had smaller spacing between precipitates was not necessarily higher than that of an alloy which had larger spacing, and there was the maximum strength in an alloy which had a certain mean spacing. (2) The relationship between fatigue strength and the mean spacing did not correspond to that between yield strength and the spacing but to that between the true rupture strength and the latter.