| Scope |
Advancements in metal additive manufacturing (MAM) technology have created the ability to design and construct parts with geometries and properties that cannot be achieved in one process through traditional subtractive machining. This ability has promoted new design strategies whose success relies on close integration of engineering with materials science. Due to the localized, rapid thermal cycles in MAM, the as-built materials have high residual stresses and significant compositional gradients. Post-build heat treatments are routinely performed to alleviate residual stresses and solidification structures with the goal of achieving microstructures and properties comparable to wrought counterparts. As the current protocols are based on thermo-mechanically processed wrought materials, the MAM materials do not have the same work history and may respond differently to the times and temperatures specified in standards.
Since AM materials are built to near-net shape, desirable microstructures and properties rely on thermal processing alone and the lack of working often leaves segregated areas. The presence of impurities like nitrogen and oxygen, originating from powder production or MAM processing, can also alter the microstructure evolution during heat treatment due to the formation of uncommon precipitates. Thus, when wrought heat treatment protocols are applied to MAM alloys, they are less effective and often promote the formation of microstructures that can potentially degrade the mechanical performance of the AM part. For this reason, post-build heat treatment protocols designed to specifically address the microstructures created by AM-processing need to be developed to produce components with more consistent properties and to improve the performance of the many industrially important alloys currently being evaluated for MAM.
The main objective of this symposium is to provide a forum to design, develop and validate strategies that improve the efficacy of thermal processing of AM components. The ultimate goal is to produce MAM material that meets or exceeds the mechanical performance of wrought-processed material. This includes approaches that increase our understanding of the relationships between complex microstructures and mechanical behavior with regards to the influences of repetitive rapid solidification on resulting microstructure, phase transformations and their influence on the strengthening mechanisms.
Abstracts are requested in the following general topic areas relating to additive manufacturing and its influence on phases and properties: transient phenomena, phase transformation, and rapid solidification. |