Springer Science and Business Media LLC

Practical experience in the use of ultrasonic material treatment during manufacture of copper alloy bars is described. Results for comparative study of wire rod microstructure, physicomechanical tests of finished product, and data for occurrence of production processes are provided. It is noted that ultrasonic vibration introduced into a melt intensifies degassing, promotes additional mixing, and prevents occurrence of dendrite liquation and non-metallic inclusion concentration at grain boundaries. All of this has a favorable effect on forming a uniform metal structure during solidification.

Computer simulation of the processes of three- and four-roller screw rolling was performed using the QForm finite element analysis computing environment with a constant and variable friction factor for roll–billet pairs. Simulation results at a constant friction factor showed that in the longitudinal section of the billet after four-roller rolling, the average value of the accumulated deformation is higher compared to three-roller rolling, and the deformation penetrates deep into the billet. The results also showed that four-roller rolling proceeds faster than three-roller rolling with a constant and variable friction factor. An analysis of the estimated speed of the billet movement during three- and four-roller rolling revealed that the return to a stable process after a sharp decrease in speed occurs faster in four-roller screw rolling than in three-roller rolling due to insufficient friction between the roll and the billet.