Session: Research Posters

Paper Number: 173398

Evaluation of Targeted Cooling Effects on Surface Integrity and Fatigue Performance of Additively Manufactured Alloys 

Additive manufacturing (AM) techniques such as Directed Energy Deposition (DED) and Electron Beam Powder Bed Fusion (EB-PBF) enable significant advancements in designing and fabricating complex, high-performance components, particularly in aerospace, medical, and energy industries. These processes allow for unprecedented design freedom, including the creation of intricate geometries, integrated internal channels, and customized features that are difficult or impossible to produce using traditional manufacturing. However, post-processing operations such as machining, grinding, polishing, and heat-treatment remain essential for achieving the stringent surface finish and dimensional accuracy demanded by functional applications. Grinding is a major secondary process applied to additively manufactured metals and is considered one of the most effective methods for achieving precision and improved surface quality in critical engineering components. Traditional grinding methods typically employ flood coolant to manage heat generation and tool wear, which involves high fluid consumption, environmental and health concerns, and can induce tensile residual stresses that adversely affect fatigue performance. Research on how targeted cooling affects surface and fatigue characteristics of additively manufactured parts is still limited and requires further systematic investigation. This study investigates targeted cutting fluid application during the grinding of AM components made from stainless steel 316L and Ti6Al4V, aiming to induce beneficial compressive residual stresses and improve overall surface integrity of these materials. The effects of conventional flood cooling and targeted air-based cooling during finish grinding were evaluated through multiple experimental techniques. Surface roughness and morphology were examined using Scanning Electron Microscopy (SEM), while residual stresses were measured via the hole drilling strain-gauge method. Vickers microhardness testing was used to assess localized hardness variations, and Optical Microscopy (OM) provided insights into microstructural changes near the ground surface and subsurface. Additionally, fatigue testing was performed, and fracture surfaces were examined using SEM to investigate fatigue crack initiation sites and propagation mechanisms under both cooling conditions in detail. Compared to traditional flood cooling, targeted air cooling significantly improved surface integrity in both materials. In Ti6Al4V, the subsurface maximum principal residual stress was reduced by 108%, surface roughness decreased by 33% and microhardness at 5 μm increased by 1%. For stainless steel 316L, targeted air led to a 120% reduction in subsurface residual stress and resulted in a fatigue life improvement of approximately 21% at 90% of the material’s yield strength. These findings demonstrate that strategic, low volume coolant delivery can simultaneously enhance surface integrity, extend fatigue performance, and reduce fluid usage in the finish‑grinding of AM metals.

Presenting Author: Safia Alam Sumaiya The University of Akron

Presenting Author Biography: Safia Alam is a PhD researcher in the Mechanical Engineering department at the University of Akron. Her research focuses on post-processing of additively manufactured metals, particularly improving surface integrity and fatigue performance through sustainable grinding techniques. She serves as the entrepreneurial lead of an NSF I-Corps team exploring targeted air-based cooling in grinding. Her work contributes to advanced manufacturing innovations in aerospace and biomedical applications.

Authors:

Safia Alam Sumaiya The University of Akron
Karthikeyan Ramachandran The University of Akron
Nithin Rangasamy The M.K. Morse Company
Sekhar Rakurty The M. K. Morse Company
Manigandan Kannan The University of Akron