The hydrostatic extrusion is a new method of extrusion process. The most important advantage of this method is reduction of friction and close tolerance for the coating thickness. In this study, the hydrostatic extrusion simulation of bimetallic wires has performed using of finite element method. In the following the advantages of hydrostatic extrusion compared to the direct extrusion are presented.It can be concluded that by increasing the friction coefficient between the work piece and the die, the extrusion force value also increases. Increasing the cross-section reduction when the die angle kept constant as a result of increase in die length, consequently leads to an increase in the extrusion force.Regarding to the absence of friction in the die and almost uniformly deformation and homogeneous in the hydrostatic extrusion, the product with a uniform coating thickness can be obtained as it is very important for manufacture of very high length bi-metal products. تفاصيل المقالة

Thin-walled aluminum alloy tubes utilized for industrial applications like aviation and car manufacturing can be produced by various processes which are mainly divided into seamless and welded tubes. The utilization of welded tubes is desired to meet the increasing need for production efficiency and flexibility in design particularly when the shape cross section is asymmetrical. In this study, the possibility of attaining the defect-free and manufacturing of friction stir welded tube of AA 6061-T6 having a wall thickness of 2.5 mm was carried out and process parameters were optimized to get a visually defect-free welded tube. In the next step, the characterization of welded tubes using rotary draw bending of the welded tubes was done. With the increase in the welding speed, the average ovality in bent tubes was decreased and with the increase in the bending speed, the ovality was decreased in rotary draw bending of friction stir welded aluminum tubes. تفاصيل المقالة