Non-destructive and automated yield strength estimation of 3D-printed Ti-6Al-4V structural components based on eddy-current measurement

Abstract

This study proposes an eddy-current-based non-destructive and automated yield strength estimation technique for the 3D-printed Ti-6Al-4V plates. First, the relationship between the electrical conductivity and the eddy-current phase value is established. Then, the electrical conductivity and the yield strength are correlated based on the theoretical expressions. For the experimental validation, the Ti-6Al-4V test specimens with various electrical conductivities (yield strengths) are fabricated by adjusting the cooling rate during the 3D printing. Finally, the yield strength estimated by the proposed technique is compared with the conventional destructive tensile test results. The results show that the proposed technique can accurately estimate yield strength with less than an 8% error. The uniqueness of this study lies in (1) the theoretical derivation of the relationship between the eddy-current phase value and the yield strength, (2) non-destructive, non-contact, and automated estimation of the yield strength using eddy-current measurement, and (3) performance evaluation of 3D-printed Ti-6Al-4V plate specimens with various yield strengths.