Investigation of Microstructure and Mechanical Properties of Al-6061 Tubes Processed by Tubular Channel Angular Pressing Process Having Trapezoidal Channel Geometry

Abstract

The many benefits of ultra-fine grained (UFG) tubes in the industry have led researchers to devise methods to increase the strength of tubes. Tubular channel angular pressing (TCAP) process is a new severe plastic deformation (SPD) technique to produce UFG tubes. In this research, at first, one pass of tubular channel angular pressing process with trapezoidal channel geometry is applied on Al-6061 samples. Then, mechanical properties such as yield strength, ultimate strength, hardness, and microstructure of the TCAPed samples are compared with the initial ones. In addition, effective strain and stress, processed load and deformation geometry during different stages of the tubular channel angular pressing process were investigated by finite element modeling. Finally, the results of the analytical model with finite element simulation were compared. It should be noted that the trapezoidal channel geometry has been used due to the high strain homogeneity and low force required for this channel geometry compared to other channel geometries. The microstructural results showed that the grain size of the initial samples was reduced from 92 µm to 785 nm in the TCAPed samples. The results of compression test showed that the yield strength and ultimate strength of the samples increased by 90% and 52%, respectively. The hardness of processed samples was also increased by 56% compared to the initial ones.