Abstract:Ultrasonic resonance technology is the most effective method for studying the ultra-high cycle fatigue properties of metal materials. Ultrasonic fatigue specimens typically need a distinctive geometric design to fulfill the resonance requirements. Traditional specimens, such as round rod and dog bone, do not have planar characteristics, which makes microscopic characterization difficult. This paper presents an ultra-high-cycle tensile fatigue specimen with a featured plane based on a traditional dog-bone tensile-compression specimen design. Different from the traditional specimen design, the dog-bone specimen herein has a flat observation area, which is readily to implement microscopic characterization. This paper takes GH4169 nickel-based alloy as an example to verify the proposed plane featured dog-bone fatigue specimen design. As expected, the ultrasonic fatigue test results show that the proposed dog-bone plane specimen can resonate at 20kHz. The measured fatigue life data is basically consistent with available S-N results in the literature. The proposed method provides new ideas for the design of ultra-high cycle fatigue specimens, as well as helps in the study of micro-deformation mechanisms of ultra-high cycle fatigue.