The improvement of mechanical properties by a thermomechanical treatment (TMT) has been investigated on a Ti-added Cu-Ni-Al alloy. Characteristics in microstructure and rolling texture were examined in relation to the mechanical properties.
In the thermomechanically treated Cu-Ni-Al-Ti alloy, the hardness, 0.2% proof stress and ultimate tensile strength reached the maximum values of 275Hv, 120kg/mm² and 121kg/mm², respectively.These values were much higher than those obtained in similarly treated Cu-Ni-Al alloys. The hardness increment of 100Hv obtained by cold rolling for the Cu-Ni-Al-Ni alloy was extremely higher than that of 60Hv for a Cu-Ni-Al alloy.
The transmission electron microscopy of the preaged and cold rolled Cu-Ni-Al-Ti alloy indicated that deformation proceeded only in matrices and the concentrated stress in matrices leads mechanical twinning. X-ray pole figures on {111} reflection showed that the rolling texture was changed into an alloy type from a pure metal type observed in a Cu-Ni-Al alloy.