The tensile properties of pseudobinary Ll3-type intermetallic compounds based on Ni3Al and Ni3Mn were examined on recrystallized specimens. The alloys with manganese composition lower than 15 at. pct were tested from room temperature to 1073 K (1273 K for some alloys). The yield stress appears to be controlled by solid solution hardening (athermal component) at room temperature and by the so-called Kear-Wilsdorf mechanism (thermal component) at elevated temperatures. The activation constant for the latter mechanism, i.e., for the anomalous positive temperature depen-dence of the yield stress, increases with increasing the manganese composition. The tensile elongation shows a maximum at 9 at. pct Mn and at intermediate temperatures (≈700 K). Also, at sufficient higher temperatures (1273 K), an increase of elongation due to dynamic recrystallization was ob-served. The temperature and compositional dependence of the ultimate tensile strength are similar to that of the elongation. The fracture mode was closely correlated with the elongation behavior: the more the transgranular fracture, the higher the ductility.
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