Characteristic microstructure and microstructure evolution in Al–Cu–Mn alloy under projectile impact

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2012, Vol.531, p.12-17
• Main Authors: Zhang, Qing Hua, Li, Bo Long, Chen, Xi, Yin, Jia Ming, Nie, Zuo Ren, Zuo, Tie Yong
• Format: Article
• Language: English
• Subjects: Adiabatic flow; Aluminum alloy; Aluminum base alloys; Applied sciences; Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures; Craters; Cross-disciplinary physics: materials science; rheology; Dynamic recrystallization; Elasticity. Plasticity; Exact sciences and technology; Materials science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Microstructure; Physics; Projectile impact; Projectiles; Slip bands; Transmission electron microscopy; Treatment of materials and its effects on microstructure and properties; Walls
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2011.09.109

The TEM image of the characteristic microstructure around the crater in 2519-T87 aluminum alloy target impacted at a velocity of 584 m/s. (a) subgrains, (b) dynamic recrystallization grains, and (c) micro-bands. [Display omitted] ► Three characteristic zones around the crater were classified. ► Dynamic recrystallization behavior were found in the adiabatic shear bands. ► The micro-cracks formed in the adiabatic shear bands. ► The dislocation slipping plays a critical role in the microstructure evolution. The microstructure and microstructural evolution were investigated near crater wall in Al–Cu–Mn alloy using optical and transmission electron microscopy (TEM) after projectile impaction. The results show that three characteristic zones around the crater can be classified based on the different microstructure, i.e. deformation bands, dynamic recovery zone and adiabatic shear bands (ASBs). The TEM observation indicates that the dislocation glide plays a crucial role in the formation of that microstructure during projectile impact. The adiabatic shear bands were formed near the crater wall and extend into matrix. It can be found that fine grains were formed within the adiabatic shear bands by dynamic recrystallization occurring during projectile impact. The micro-cracks have been developed along the adiabatic shear bands. However, It is demonstrated that the formation of deformation bands are favorable for improving anti-impact property of Al–Cu–Mn alloy, but adiabatic shear bands are easily to initiate micro-cracks, leads to the failure of target material.