The cavitation behavior of a coarse-grained Al5052 alloy under hot uniaxial and equibiaxial tension

摘要

In this paper, the cavitation behavior of a commercially available coarse-grained Al5052 alloy under hot uniaxial and equibiaxial tension was studied for the first time. Tensile specimens were strained to different strain levels at various initial strain rates and temperatures. The results revealed that there was no significant difference in the cavitation size distribution under different stress states, and the spread of cavity size and the total number of cavities were found to increase with increasing strain. In microstructural examination, some voids were observed at the interface between the intermetallic particles and the matrix, and they were growing continuously with increasing strain. Quantitative analysis revealed that the cavity growth was essentially plasticity-controlled. A lower cavitation growth rate was observed for the Al5052 alloy as compared to that of the superplastic Al5083 alloy, which could not explain the relatively low elongation value of 194% of Al5052. It was considered that the hot formability of Al5052 did not only relate to its cavitation behavior, but also its strain rate sensitivity value.