Flash Sintering Phenomenon In Aluminum Alloy Powder

DC electric currents were applied during free sintering of aluminum alloy (AA5083) green powder compacts and it was found that the kinetics of sintering were greatly enhanced compared to samples processed without a field. In-situ sintering kinetics during sintering with electric field strengths and amperages ranging from 0-56 V/cm and 0-3 A were quantified using digital image correlation (DIC). It was found that the application of a DC field during sintering results in a discontinuous change in volume at a critical temperature along with a transition in electrical properties of the compact from insulating to conductive. This effect is similar to the phenomena observed in the flash sintering process currently being actively researched for ceramic powder processing. The temperature at which the flash event occurs was found to be field strength dependent and doubling the field strength was found to decrease the flash temperature by 25%