Effect of Multidirectional Forging on the Grain Structure and Mechanical Properties of the Al–Mg–Mn Alloy

Abstract

The effect of isothermal multidirectional forging (IMF) on the microstructure evolution of a conventional Al–Mg-based alloy was studied in the strain range of 1.5 to 6.0, and in the temperature range of 200 to 500 °C. A mean grain size in the near-surface layer decreased with increasing cumulative strain after IMF at 400 °C and 500 °C; the grain structure was inhomogeneous, and consisted of coarse and fine recrystallized grains. There was no evidence of recrystallization when the micro-shear bands were observed after IMF at 200 and 300 °C. Thermomechanical treatment, including IMF followed by 50% cold rolling and annealing at 450 °C for 30 min, produced a homogeneous equiaxed grain structure with a mean grain size of 5 µm. As a result, the fine-grained sheets exhibited a yield strength and an elongation to failure 30% higher than that of the sheets processed with simple thermomechanical treatment. The IMF technique can be successfully used to produce fine-grained materials with improved mechanical properties.

The Effect of Isothermal Multi-Directional Forging on the Grain Structure, Superplasticity, and Mechanical Properties of the Conventional Al–Mg-Based Alloy

“…IMF provided a YS of 300 MPa and a UTS of 405 MPa. However, a typical YS value is 170-180 MPa and a typical UTS value is 300-320 MPa for conventionally proceeded samples [44], and mode C-processed samples exhibited similar values. Despite the inhomogeneous grain structure, samples exposed to IMF exhibited 17% elongation, which is close to the values of conventionally processed sheets.…”

A review on primary synthesis and secondary treatment of aluminium matrix composites

“…The author reported a reduction in the grain size of samples subjected to secondary treatment. Some researchers use thermomechanical processes as fabrication routes (Khodabakhshi et al, 2018) or as thermomechanical treatment for ameliorating detrimental defects inherent in as-synthesized composites (Hussain, Rao, Singh, & Jayaganthan, 2018;Jaseem et al, 2018;Joshi, Yogesha, Kumar, & Jayaganthan, 2016;Kishchik et al, 2018). There are some studies where thermomechanical treatment was deployed as secondary treatment for other composites.…”

A multi-response optimization of the multi-directional forging process for aluminium 7075 alloy using grey-based taguchi method

“…During the MDF process, various studies have used input parameters differently. Some researches have been conducted at temperatures ranging from room temperature [8] to extremely high temperatures of up to 500 K [9,10]. Other input process parameters studied include; strain per pass (the strain of every single pass ranging from 0.2 to 0.7), die velocity, friction coefficient, and the geometry of the sample (size and shape) [9].…”

“…Some researches have been conducted at temperatures ranging from room temperature [8] to extremely high temperatures of up to 500 K [9,10]. Other input process parameters studied include; strain per pass (the strain of every single pass ranging from 0.2 to 0.7), die velocity, friction coefficient, and the geometry of the sample (size and shape) [9]. Most researchers have considered some variables of the process as constants while varying others to examine how they affect the MDF [3,8,[11][12][13].…”