|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Additive Manufacturing of Metals: Establishing Location-Specific Processing-Microstructure-Property Relationships
||Understanding the Columnar-to-Equiaxed Transition in Additive Manufacturing
||Mark Easton, Dong Qiu, Mitesh Patel, Gui Wang, Milan Brandt, David StJohn
|On-Site Speaker (Planned)
Typically, additively manufactured alloys have a columnar grain structure. This may be due to either the AM process, where large temperature gradients tend to encourage the formation of columnar grains; or the alloys, where typically used alloys such as Ti6Al4V have low solute that does not generate constitutional supercooling and consequently does not favor equiaxed grain formation. This paper investigates how laser surface remelting affects the grain structure of cast Al-Cu, and Al-Si alloys with and without the addition of Al-Ti-B grain refiner additions. Laser remelting of the alloys without grain refiner additions led to large grains with very fine dendrite arms in the re-melted region. However, when grain refiner was added very fine equixed or mixed columnar-equiaxed zones were observed. Typically slower laser scan speeds led to a more equiaxed structure as did higher alloy contents.
||Planned: Supplemental Proceedings volume