Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


Mechanical Engineering

Committee Chair

George J. Nelson

Committee Member

Babak Shotorban

Committee Member

Gang Wang

Committee Member

Jason R. Mayeur

Research Advisor

Kavan Hazeli


Copper alloys--Mechanical properties, Structural analysis (Engineering), Thin-walled structures


This study investigates size effects on microstructure, mechanical behavior, and fatigue performance of additively manufactured GRCop-42. Systematic analyses, encompassing changes on powder composition, wall thickness, and heat treatment, was conducted on specimens produced through laser powder bed fusion (L-PBF) and laser powder direct energy deposition (DED) techniques. L-PBF specimens exhibited a reduction in strength and elongation with decreasing thickness, attributed to increasing porosity as specimen’s thickness decreases. Conversely, in DED specimens, decreasing mechanical properties with thickness were associated to surface topography. Emphasizing the non-generalizability of size effects across AM methods. Size effects were also investigated on high cycle fatigue, as tensile properties cannot be readily translated into fatigue properties. Fatigue testing of L-PBF specimens revealed internal defects as operative features responsible for an early fatigue failure, which were remediated by hot isostatic pressing. Fractography unveiled size-dependent fatigue characteristics, particularly an increased presence of brittle features on thinner specimens. This investigation highlights the significance of size effect considerations for GRCop-42 in AM applications.



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