Mechanical and electrical properties of bolted aluminium alloy bus bars exposed to high temperaturesThursday (09.11.2017) 09:55 - 10:15 Part of:
The effect of dispersoids on the long-term behaviour of bolted bus bars made of aluminium alloys EN AW-3105, EN AW-6101A and EN AW-8076A was investigated. Long-term experiments on bolted joints up to 10,000 h at 140 °C were performed with force measuring devices to monitor the joint force decreases due to softening. Further, the electrical and mechanical properties of the bus bar materials were investigated during the long-term experiments by electrical conductivity measurements and hardness testing. As a result, the bolted joints made of aluminium alloy EN AW-3105 exhibit the highest remaining joint force and seem to be a suitable candidate for long term applications at elevated temperatures. This has been correlated with the formation of strengthening Al(Mn,Fe)-Si dispersoids. The evolution of such dispersoids has been investigated along the production chain of aluminium alloy busbars, i.e. casting, homogenization, extrusion, etc. by means of in-situ DSC as well as SEM and TEM.