Abstract
A major disadvantage regarding integrally bladed rotors (IBRs: also referred to as blisks) is the ability to repair damage. Since it is a single part, anything beyond a minor dent requires full removal and either an expensive replacement or a complicated repair. Repair approaches gaining attention include additive metal build-up techniques such as blown powder directed energy deposition (DED). As a start and to attain confidence in such repairs, the characterization of additively modified specimens is required. The work presented here involved the tensile and fatigue testing of stock, annealed Ti-6Al-4V and DED repaired specimens. Thin, dog-bone standard test coupons, consisting of half stock material and half additively manufactured (AM) material with a bond line in the center of the specimen gauge section, were mechanically characterized via tensile and fatigued tests. The behaviors of these “50/50 AM repaired” Ti-6A1-4V coupons were compared to 100% stock Ti-6A1-4V coupons. In addition, metallography and post-test fractography were performed to study the microscopic characteristics and failure initiation sites with special attention to the grain structures in the vicinity of the bond lines. The AM repaired coupons did show a slight degradation in mechanical properties compared to the stock material of this study (tensile strength and elongation as well as fatigue life), with the microstructural dissimilarities explaining the variances. Even so, the AM repaired specimen properties were acceptable and compared favorably to other published results for stock annealed Ti-6A1-4V.
