Theoretical and experimental study on the fatigue property of material extrusion products and improvement by using vibration machining during manufacturing process

Nowadays, material extrusion (ME) is one of the most popular additive manufacturing technology, which offers a new way of manufacturing parts with specific complex geometry and mechanical properties. However, with the expansion of the application range of ME products, it is urgent to investigate their fatigue property so as to ensure the reliability and safety. In this paper, the damage mechanical fatigue life prediction model of ME products considering void defects was established. Fatigue test specimens built with different processing parameters were then fabricated, and tensile fatigue tests were carried out under different stress levels. In addition, a novel method, utilizing vibration during ME process, was proposed to improve the built products' fatigue property, and corresponding theoretical and experimental investigations were performed to reveal the influencing mechanism of the vibration utilized. The results showed that the proposed model was validated by comparing the theoretical predictions with the experimental measurements. As layer height and printing speed were increased, the fatigue life of ME specimens dropped, while it rised with the increasing extrusion temperature. The built products' fatigue life could be improved obviously by using vibration.