Continuous dynamic recrystallization prediction in multi-direction loading forming of 7075 aluminum alloy tee valve

Abstract

In multi-direction loading forming of 7075 aluminum tee valve, continuous dynamic recrystallization (CDRX) will occur and affect the final microstructure and performance. In this paper based on the developed physically-based internal state variable model and finite element (FE) simulation, under the reasonable forming parameters, the evolution behavior and law of the dislocation density, subgrain size, average misorientation of subgrain boundary and average grain size were revealed, especially in the intersecting region at different multi-direction loading forming stages. It is also shown that when the horizontal and vertical punches are loaded simultaneously, the CDRX degree decreases while grain size increases gradually from the inner to outer wall of branch tube. In the intersecting region, the average grain size increases from the inside to outer corner. The results can provide a guide for the quick prediction of CDRX and selection of the reasonable forming parameters for multi-direction loading forming of tee valve.