An Experimental Investigation on a Modified Friction Assisted Tube Straining Method

This paper presents a novel severe plastic deformation method entitles modified friction assisted tube straining for producing ultrafine-grained cylindrical tubes. Using friction power generates heat to locally increase temperature of the deformation area and creates severe combined strains and lower pressing force. Experimental tests were executed on Cu/30Zn alloy to investigate applicability of the presented method. The optimum process parameters, 710Rev/min rotary speed and 0.08mm/Rev feed rate were found, applying experimental test to process tubs fault free.  Microstructure study of processed specimens showed a significant grain refinement from the initial value of 76μm to 9μm and 7μm in longitudinal and peripheral directions, respectively. Yield stress and ultimate tensile strength of processed specimens increased to 325 and 202MPa from the initial values of 160MPa in peripheral and longitudinal directions, respectively. Also, hardness significantly increased to 72Hv from the initial value of 48Hv.