Identification of Flaws and Assessment of Mechanical Properties in Additively Manufactured Titanium Parts Using Acoustic Resonance Ultrasound Spectroscopy (RUS)

Abstract

Additive manufacturing (AM) techniques are becoming accepted as routine in many industrial fields that include aerospace applications. This ramp up in manufacturing has highlighted a fundamental need for innovative nondestructive testing (NDT) methodologies for AM inspection and qualification purposes. Resonance Ultrasound Spectroscopy (RUS) is beginning to be applied as an innovative NDT inspection technique for AM components to obtain insights from the parts’ structural integrity and because it correlates to mechanical properties. RUS is used to understand sensitivity to detecting internal flaws, resulting in lower than expected failure resistance or fatigue life. Multiple test bar batches using the Ti6Al4V alloy were fabricated by powder bed fusion (PBF) AM technique at different processing conditions. RUS and destructive tests, including tensile and fatigue tests, based on ASTM standards are performed in order to evaluate the mechanical properties and tensile and fatigue strength of the parts. Finally, metallography experiments revealed the microstructure of the parts. The goal of correlation analysis is to establish the defect-NDT-property relationship for the Ti6Al4V by showing the strength and significance of the relationship between the testing data and the properties of the samples. Results show that RUS is a reliable and capable NDT technique to acquire rapid information for this purpose. This information is crucial for expanding the production and application of AM components while making sure that the mechanical properties, their structural integrity, and part safety satisfy the requirement of the lifetime operation.