|About this Abstract
|Materials Science & Technology 2020
|Additive Manufacturing: Alloy Design to Develop New Feedstock Materials
|3D Characterization of Cracks Formed in “Weldable” AA6061 and Implications for Alloy Design
|Giuseppe Del Guercio, Graham McCartney, Nesma Aboulkhair, Chris Tuck, Marco Simonelli
|On-Site Speaker (Planned)
|Giuseppe Del Guercio
Solidification cracking is one of the major issues in the development of Laser-Powder Bed Fusion (L-PBF) of high strength Al-alloys. Weldability and cracking indices developed for processes where single heating/cooling profiles are imposed present shortcomings in predicting cracking behaviour during L-PBF - where materials experience multiple thermal cycles. In this talk, we investigate the origins of the cracking phenomena in the “weldable” aluminium alloy AA6061, to expose the merits and limitations of weldability indices in the context of L-PBF. The cracks formed in printed AA6061 and AA6061+Si (to mimic the influence of typical welding fillers) are characterised in 3D using a plasma FIB-FEGSEM to understand the effects of elemental segregation, crystallographic texture and dendrite morphology on the cracking phenomena. Such fundamental understanding is of paramount importance and will be discussed in relation to a newly proposed alloy design strategy for high strength aluminium alloys for L-PBF.