Complex Stress Creep Relaxation of Metallic Alloys at Elevated Temperatures: An Investigation Covering an Aluminium and a Magnesium Alloy

The nature of the relation between complex stress creep under conditions of relaxation and complex stress creep under conditions of steady stress was investigated. The required relation has been examined for an RR59 aluminium alloy at 200 deg. C. and for a magnesium (2 per cent aluminium) alloy at 50 deg. C. For RR59 aluminium alloy at 200 deg. C. and for magnesium (2 per cent aluminium) alloy at 50 deg. C., a reasonably close prediction of the course of relaxation complex stress time curves is given by the mechanical age hardening theory of creep on the basis of steady complex stress creep data. Other mechanical theories tend to predict for a specific relaxed stress a relaxation time in excess of that noted in experiment.