Effect of Cu on Microstructure of Al-Ti-B Trapezoidal Continuous Casting Billets

The trapezoidal continuous casting billet Al-5Ti-1B-0.2Cu intermediate alloy was used as the research object, and the solution treatment was carried out at different temperatures, and then the thermal compression deformation was carried out at different deformation temperatures and strain rates in various deformation directions. The effects of Cu element addition, solid solution treatment, and hot compression on the microstructure and dimensional inhomogeneous deformation of second phase particles was studied. The results show that there are four types of second phase particles, including (Ti,Al)B-2, Al7Cu2Fe, 7 Cu 2 Fe, TiB2, and TiAl3, in the Al-5Ti-1B-0.2Cu intermediate alloy after solid solution treatment at 600 degrees C for 4 h. When Cu is present, the Al-Cu-Fe phase is generated to increase the number of the second phase particles. At the same deformation degree and deformation temperature, the average grain size of TiAl3 particles decreases with increasing the deformation rate (0.01, 0.1, 1 s(-1)), while TiB2 particles tend to be more diffusely distributed. The second phase particles TiAl3 are more uniform after transverse compression deformation and finer after longitudinal compression deformation, and the size and distribution of TiB2 particles after transverse compression and longitudinal compression are basically the same. The dimensional inhomogeneous plastic deformation of the trapezoidal continuous casting billet is more favorable to the size and distribution of the second phase particles TiAl3 and TiB2.