Impact fatigue behaviors of Ti6V4Al alloy under compressive and tensile stresses

Abstract

Impact fatigue behavior of Ti6V4Al alloy against GCr15 steel was tested under applied tensile and compressive stresses. The wear loss volume of the Ti6V4Al alloy in NaCl solution was obtained. Scanning electron microscopy analysis was used to determine the impact fatigue mechanism. Results show that the wear loss increased with an increase in impact load. When the applied stress was at the same magnitude, the wear loss of the samples under tensile stress was lower than for those samples subjected to compressive stress, and the wear loss for both samples was are higher than that under no applied stress condition. This result is related to changes in the spalling modes in fatigue delamination: under tensile stress, microcracks grow preferentially to the surface in a perpendicular direction to the tensile stress, whereas compressive stress induces microcracks to incorporate and form de-bonded regions below the surface, which causes more impact wear damage.