Tensile and fatigue behaviors of newly developed HAYNES® 233 alloy: Additively manufactured vs. wrought

The tensile and fatigue properties of a newly developed Ni-based superalloy, HAYNES® 233, were investigated. Two different manufacturing processes including hot rolling (wrought plate) and laser-powder directed energy deposition (LP-DED) were considered. In addition, specimens were tested in two heat treatment (HT) conditions, namely solution annealed (SA), and age-hardened (AH). The microstructures of the materials were characterized using a scanning electron microscope. Tensile properties of specimens were evaluated at 21 °C, 538 °C, and 871 °C along with the fatigue properties at 21 °C under two different strain amplitudes of ε_a = 0.005 mm/mm and ε_a = 0.002 mm/mm. The LP-DED material in both the SA and AH conditions showed similar tensile strengths to the wrought AH material at all test temperatures, whereas the wrought SA material showed a noticeable deficit in strength at 21 °C and 538 °C, and was only comparable at 871 °C. Fatigue results indicated that there was no significant difference in fatigue life for specimens tested at ε_a = 0.005 mm/mm, while differences in fatigue life were observed for specimens tested at ε_a = 0.002 mm/mm, where fatigue life was observed to correlate well with the size of the crystallographic facets at crack initiation sites.