Tensile behavior upon ordering of Ni3Fe single crystals.

Abstract

The tensile properties of ordered and disordered Ni3Fe single crystal have been investigated. Also, poly crystalline specimens have been tested to show the influence of grain size on the deformation characteristics of Ni3Fe. Measurements have been made to determine the influence of parameters such as the initial orientation of the tensile axis of single crystals, the ordered domain size, and the test temperature on the mechanical properties of Ni3Fe. Tensile axis reorientation during deformation was followed with x-ray techniques. It was found that in ordered single crystals, the measured tensile axis rotation agrees well with the calculated values if one activated glide system is assumed. The influence of secondary slip on the tensile characteristics of ordered crystals was determined by using specimens oriented for multiple glide. It is demonstrated that the work hardening rate increases with the occurrence of secondary slip. The strain-aging phenomena shown previously in poly crystalline Ni3Fe was found to occur also in single crystals. The nature of the observed effects in ordered Ni3Fe is interpreted in terms of the antiphase boundary tube mechanism.