DIFFERENTIAL THERMAL-ANALYSIS OF SOLID ZIRCONIUM

Several observations are made in the differential thermal analysis (DT A) test of solid zirconium (Zr) specimens. It is found that an increas ing heating rate generally increases the solid-phase transition temper ature for both nondeformed and cold-worked specimens, but to a differe nt extent. Upon cycling the specimen with a constant heating rate, the phase transition temperature decreases initially during the first few runs and then remains constant. Also, holding a specimen for some tim e just before the phase transition during heating increases the phase transition temperature. Specimen heating history and prior cold work a re also found to influence the solid-phase transition temperature.