In situ metallic porous structure formation due to ultra high heating and cooling rates during an electromagnetic pulse welding

Porous structure formation resulted at the interface of electromagnetic pulse welded joints are investigated and revealed, to identify the, development of sub-micron to few micron sized pores due to ultra high rate of heating and cooling. Collision velocity along the overlapping length was predicted using a multi-physics numerical simulation and subsequently this velocity field was used to estimate the heating and cooling rates as about 10(9) degrees C s(-1). Predicted temperature, pressure and strain variations clearly evidence the observations of porous structure formation that is potentially facilitated by sequential phenomena of pores nucleation, coalescence and growth within the molten intermediate phase. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.