Microstructure evolution during FSW/FSP of high strength aluminum alloys

Recrystallization mechanisms during friction stir welding/processing of aluminum alloys

“…Friction stir welding (FSW) and friction stir processing (FSP) technologies involve SPD but under conditions that include rapid transients and steep gradients in strain, strain rate and temperature [8,9]. Microstructure transformations and restoration processes in the presence of such transients and gradients have only recently begun to be considered [10][11][12]. Nevertheless, these processes determine the microstructure and properties of welded or processed materials, and it is imperative to gain better understanding and control of recrystallization in these circumstances.…”

Microstructure and Mechanical Characterization of a Dissimilar Friction-Stir-Welded CuCrZr/CuNiCrSi Butt Joint

“…Su et al [21] reported that repeated introduction of dislocations after dynamic recrystallization initiates partial recovery in the NZ, so the final grains are in state of dynamic recrystallization and partial dynamic recovery. What's more, it is observed that sub-grains grow with dislocations absorbed into sub-boundaries in the NZ from Figure 3c,d, which means the dynamic recrystallization process is a continuous dynamic recrystallization process [22].…”

Efeito dos parâmetros de processo na obtenção e na microestrutura de juntas alumínio-aço realizadas mediante soldagem por atrito com pino não consumível (SAPNC)

“…Posterior à recristalização, os grãos a Al crescem como conseqüência da temperatura, mas o metal plastificado ainda continua sob a influência das condições termomecânicas oriundas do processo, provocando a recuperação dinâmica do metal [26]. Porém, a recuperação na ZM é heterogênea devido às diferenças no campo de deformações em volta da ferramenta, o que explica a presença de grãos com densidade e arranjos de discordâncias diferentes [26], como mostrado na Figura 8.…”