Mechanical Integrity of 3D-printed Stainless-steel Structures Characterized by Ultrasonic Fatigue Testing

Authors: Noelle Boruta, Ping-Chuan Wang

SUNY Campus: SUNY New Paltz

Presentation Type: Poster

Location: Old Union Hall

Presentation #: 56

Timeslot: Session C 1:45-2:45 PM

Abstract: 3D-printing, also known as additive manufacturing (AM), has increasingly been employed to fabricate engineering structures in recent years. This technology offers advantages in fast prototyping and the capability of realizing complex designs that cannot be achieved by traditional manufacturing. In particular, the development of various metal AM techniques offers exciting opportunities for mainstream applications. However, it is well known that the mechanical integrity of AM parts suffers from defects associated with AM process, including surface roughness and lack of complete densification. It is thus of critical importance to investigate how AM process parameters affect the mechanical properties. This research project aims to develop a methodology to characterize the mechanical integrity of AM stainless steel parts, focusing on fatigue failure mechanisms. The ultimate objective is to determine how printing direction and surface defects influence fatigue lifetime, with the goal of improving design and reliability. We develop an ultrasonic test system and methodology to characterize fatigue behavior of AM stainless steel structures, comprising a pair of printed specimens sandwiching a pressure transducer that is coupled to an ultrasonic generator with built-in phase-locked loop, and a data acquisition algorithm to extract the fatigue behavior during testing. In this presentation, we demonstrate the feasibility of this test system by studying the heat generation through ultrasonic excitation and how it affects the resonance frequency of the test specimens. Plans for future study will be discussed.