Effect of heat treatment on precipitate free zones and rollability of V55Ti30Ni15 alloys

• The PFZs widths increased with increasing heat treatment time and temperature.
• The orientation relation between the precipitated NiTi and the V-matrix was analyzed.
• The rollability of the heat treated alloy is better than that of the as-cast alloy.
• The PFZs played an important role in the rolling process of V55Ti30Ni15 alloys.

Various heat treatment processes were performed to modify the precipitate microstructures and rollability of V55Ti30Ni15 alloys. SEM and TEM results showed that NiTi particles precipitated from V-matrix and precipitate free zones (PFZs) were formed at the boundary of V-matrix grain during heat treatment. The orientation relationship between the precipitated NiTi and the V-matrix was analyzed. The PFZs widths monotonically increased with increasing heat treatment temperature and time. The rollability of the heat treated alloy is better than that of the as-cast alloy, and PFZs played an important role in restricting cracks extension and coordinating deformation during rolling process.