Simulation and Experimental Research on Continuous Extending Rheo-extrusion Process for Producing 6201 Alloy Tube
6201合金管材连续流变扩展挤压成形过程的数值模拟和实验研究

Simulation and experimental investigation of temperature field distribution and metal flow behavior of 6201 alloy were conducted in this paper. The results show that during extending rheo– extrusion process, the isothermal lines of alloy deviate to the roll side in the roll–shoe gap, and semisolid region moves down little by little with the decrease of pouring temperature. Alloy melt in the roll–shoe gap flows by Newton laminar fluid law, and the velocity decreases gradually from the roll surface to the shoe surface where the velocity reaches 0 m·s 1. Alloy melt fills the extending cavity with a radial pattern layer by layer, and then it splits and concentrates. It also exhibits homogenous laminar flow. The flow velocity is maximal at the centers of the mould and the branch holes, and decreases gradually to the side wall. The flow lines on the cross section of the tube corresponding with the branch holes center and the wielding region are dense. But there is a transitional region where the flow line is sparse. The proper pouring temperature for producing 6201 alloy tube is between 750oC  and 780oC.