Hot Deformation and Processing Maps of 7005 Aluminum Alloy

Abstract

The deformation behavior of 7005 alloy was studied by hot compression tests. The processing map was constructed by superimposing the instability map over the power dissipation map at a strain of 0.7 using the corrected flow stress data to eliminate the effect of friction. Microstructural examination was performed for validation. It can be found that the flow stresses increase with the decrease of deformation temperature or the increase of strain rate. At the relatively high strain rates, the material exhibits flow instability manifesting as adiabatic shear bands or flow localization. A large volume of coarse precipitations distributing in the grain boundaries in one of the peak efficiency domains: 275-325 °C/0.0005-0.001 s −1 , which may result in inter-granular corrosion and spalling layer, should be avoided in the final deformed alloy. The optimum hot working domain is the temperature range of 400-450 °C and strain rate range of 0.0005-0.005 s −1 , at which DRX is identified.

Hot Compression Deformation Behavior of the Mg-5Sn-2.5Pb Magnesium Alloy

“…The true stress-strain curves of Mg-5Sn-2.5Pb magnesium alloy are presented in Fig.1. A similar phenomenon can be observed in true stress-strain curves of the other alloys [8][9][10][11]. The flow stress increase to a peak at a relatively low strain due to the forming mechanism dominated by work hardening.…”

“…Then in the subsequently deformation period, the stress decrease as a result of dynamic recrystallization (DRX) which overtakes initial work hardening. The stress reach to a steady state is mainly attributed to work hardening and softening reach a dynamic equilibrium, the dislocation density remains relatively constant, the softening phenomenon is due to the dynamic recovery (DRV) and dynamic recrystallization (DRX) [8,[12][13]. The flow stress significantly affected by strain rate and deformation temperature [12][13][14].…”

Effects of initial aging time on processing map and microstructures of a nickel-based superalloy

“…The optimum hot working parameters for Al6063/0.75Al 2 O 3 /0.75Y 2 O 3 nano-composite were identified, and the flow instability characteristics were validated by processing maps and micrographs [37]. Additionally, the processing maps were developed for some other important alloys or composites, such as Al-Cu-Li alloy [38], Al-Cu-Mg alloys microalloyed with Sn [39], DC cast Al-15% Si alloy [40], SiC particles reinforced metal matrix composites [41], as-cast AISI M2 high-speed steel containing Mischmetal [42], Aluminum-5 wt% B4C Composite [43], near-α titanium alloy IMI834 [44], extruded Mg-12Li-1Zn BCC alloy [45], as-cast Ti-43Al-4Nb-1.4W-0.6B alloy [46], (SiCpþMg2B2O5w)/6061 Al hybrid and SiCp/6061 Al composites [47], Al-Cu-Li-Sc-Zr alloy [48], 7005 aluminum alloy [49], and 800H alloy [50].…”

Hot Compression Deformation Behavior of AE42 Magnesium Alloy

“…Because true stress-strain curves at varied conditions have similar trend, therefore the true stress-strain curves at the temperature of 450 ℃and at stain rates of 0.01 s -1 was chosen to discuss the phenomena and forming mechanisms of the AE42 in these curves as shown in Fig.2. The flow stress increases sharply with increasing strain in the initial stage of the deformation process due to working hardening caused by dislocation pile-up, reduplication, and tangle [8], until it reaches a peak stress where dynamic softening occurs caused by the dislocation rearrangement and the counteraction of dislocations [9], and the flow stress tends to become steady owing to the dynamic balance between working hardening and softening. The softening is attributed to the dynamic recovery (DRV) and the dynamic recrystallization (DRX) [10].…”