Journal Published Online: 26 October 2018
Volume 7, Issue 1

Fatigue and Corrosion Fatigue Properties of Additive-Manufactured Nickel Alloy 625 and Ti-6Al-4V

CODEN: MPCACD

Abstract

Specimen blanks of additive-manufactured nickel Alloy 625 and Ti-6Al-4V were produced by the laser powder-bed-fusion process (L-PBF) with the principal test axis in both the Z direction (parallel to the build direction) and the X-Y direction (perpendicular to the build direction). The high cycle fatigue and corrosion fatigue properties of these metals were measured using R. R. Moore rotating cantilever fatigue tests, both in air and with a salt water drip on the test sections. Testing was conducted in order to determine the fatigue and corrosion fatigue limits of these materials at 108 cycles. The fatigue limit for L-PBF Alloy 625 material at 108 cycles in air was roughly 48 ksi (331 MPa), independent of build orientation. This is similar to the air fatigue limit of wrought material. The corrosion fatigue limit for L-PBF Alloy 625 material at 108 cycles in salt water was roughly 39 ksi (269 MPa), which was also independent of build orientation and slightly below the values for wrought material and values obtained by other investigators. The fatigue limit for hot isostatic pressed L-PBF Ti-6Al-4V material at 108 cycles in air was roughly 90 ksi (620 MPa), independent of build orientation. This is significantly better than the air fatigue limit of wrought material. The corrosion fatigue limit for L-PBF Ti-6Al-4V material at 108 cycles in salt water was roughly 78 ksi (540 MPa), which was also independent of build orientation, better than values for wrought material, and comparable to values obtained by other investigators. The fatigue crack growth rate behavior in air was characterized and compared with information available in the literature.

Author Information

Hack, Harvey
Northrop Grumman Corporation, Annapolis, MD, USA
Olig, Scott
U.S. Naval Research Laboratory, Washington, DC, USA
Knudsen, Erik
U.S. Naval Research Laboratory, Washington, DC, USA
Link, Richard
United States Naval Academy, Annapolis, MD, USA
Beckwith, Adelina
U.S. Naval Research Laboratory, Washington, DC, USA
Arcari, Attilio
U.S. Naval Research Laboratory, Washington, DC, USA
Pages: 12
Price: $25.00
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Stock #: MPC20170150
ISSN: 2379-1365
DOI: 10.1520/MPC20170150