A study of various heating effects on the microstructure and mechanical properties of AA6082 using EBSD and CPFE

Abstract

The solution heat treatment (SHT) process resolving hardening precipitates in high strength aluminium alloys is a critical step for high-efficient forming processes, such as Hot Form Quench (HFQ ®). SHT largely determines the overall cycle time of a forming process. However, effects of heating process parameters, such as the heating rate and soaking time, on the microstructure and the associated mechanical properties of aluminium alloy 6082, one of the most commonly used aluminium alloys, for HFQ applications have not been systematically investigated. The aim of this study is to explore and understand the relationships among heat treatment conditions, grain microstructure and associated mechanical properties for AA6082. A series of uniaxial tensile tests conducted under various SHT conditions revealed significant variation on mechanical behaviour characterised by stress-strain curves. To correlate these stressstrain relationship with underlying microstructure, the grain and orientation distribution of each heat-treated sample were characterised by the electron backscatter diffraction (EBSD) technique. Due to the presence of a large number of microscopic variables, such as grain size, morphology, texture, grain boundary and etc., the crystal plasticity finite element (CPFE) modelling was employed to identify the key microscopic factors which determine the differences in the observed strength and ductility for all samples. A new CPFE model integrated with local strain criterion was proposed and validated to correlate the ductility and the strength with the material microstructure. This rigorous investigation provides more insights on how microstructure (grain size and texture) affects the mechanical behaviour for AA6082, which enables to enlarge the capability of HFQ for industrial applications.

Investigation of the Hot Stamping-in-Die Quenching Composite Forming Process of 5083 Aluminum Alloy Skin

“…Some researchers have applied this manufacturing process to make the side wall outer panel of metro vehicles and bonnets [ 25 , 26 ]. The hot stamping-in-die quenching composite forming process (HFQ) for aluminum alloys was proposed by Lin [ 27 , 28 , 29 , 30 , 31 , 32 ]. This process is an ideal method for solving the problems of aluminum alloys at room temperature and is more productive than SPF [ 33 , 34 , 35 , 36 ].…”

Thermal Creep Behavior and Creep Crystallization of Al-Mg-Si Aluminum Alloys

“…Softening phenomena such as DRV and DXR often occur in conjunction with the thermal deformation of the metal. For the 6082-aluminum alloy, current research is focused on corrosion, machining processes, and weldability [14][15][16][17][18][19]. Numerous scholars have also conducted studies on the heat deformation behavior of metals.…”

Investigation of forging performance for AA6082

“…The forgeability increases by increasing soaking duration due to the homogeneous distribution of the phases inside the microstructure at the dissolution stage [11][12][13]. A 15 minutes waiting time at 540 °C is suggested for dissolution [14].…”