@maxhossfeld

Time-dependency of mechanical properties and component behavior after friction stir welding

. The International Journal of Advanced Manufacturing Technology, (Jan 31, 2019)
DOI: 10.1007/s00170-019-03324-x

Abstract

This paper reports on the time dependency of mechanical properties and component behavior during the first hours after friction stir welding (FSW). Three different aluminum alloys, two age-hardened alloys AA 6014-T4 and 6016-T4 and as a reference 5182-O/H111, are welded and samples are taken from the steady-state region immediately. Those samples are examined at various time intervals by means of tensile and hardness testing to quantify local properties and their recovery over time. Initially, the FSW process leads to a significant reduction in mechanical properties of the age-hardened alloys and to an altered, time-dependent component behavior as opposed to the base material. For AA 6014 and 6016, all mechanical properties recover significantly within a few hours after welding, whereby the gradient is initially very steep and levels out after 1--2 days. Gradients of up to 6 MPa/h and relative increases of more than 25\% are observed for ultimate tensile strength within the first 2 days. As such, the increase in strength within the heat-affected zone and with it the entire welded component can be compared to natural aging after solution annealing. The results show the importance of considering the time dependency for weld qualification and also for comparing studies of age-hardenable alloys.

Links and resources

Tags

community

  • @ifsw
  • @maxhossfeld
@maxhossfeld's tags highlighted