In-Situ Fitness-for-Service Assessment of Aluminum Alloys Developed for Automotive Powertrain Lightweighting

Evaluating the high-temperature creep behaviour of the Al alloys used in the automotive industries has attracted a great deal of attention from researchers over the last decade. However, very little investigation into the high-temperature tertiary creep of Al alloys has been published to date. In this study, in-situ neutron diffraction analysis was employed in order to evaluate the tertiary creep behaviour of A206 aluminum alloy under tensile load at 225 degrees C. The selected pressure and temperature was chosen to simulate actual in-service condition experienced by the automotive powertrain components; e.g. cylinder block and engine head. The results of the in-situ neutron diffraction revealed the tertiary creep behaviour of the selected {111} planes in A206 via monitoring the full width at half maximum (FWHM) of the diffraction peak and creep strain (%). This technique is first of a kind, which provides a method to observe damage accumulation during tertiary creep prior to actual observed material failure (fracture) in the A206 alloy at high temperature.