Primary Recrystallization and Grain Growth of Tough Pitch Copper Wire

Tough pitch copper wire (99.97% Cu) is generally characterized by the spiral elongation number. The principle of the test is based on the influence of impurities on the recrystallization kinetics. Alternative non-metallographic techniques to characterize the recrystallization kinetics have been investigated in this study, such as differential scanning calorimetry (D.S.C.) and residual electrical resistivity measurement. The influence of different impurity levels on recrystallization is discussed. Furthermore, discontinuous grain growth in hot rolled rod is reported.. As the heat released in this process is much smaller than in the case of primary recrystallization, D.S.C. is less appropriate to detect it and therefore a technique based on the attenuation of ultrasonic waves is proposed.