ULTRASONIC ADDITIVE MANUFACTURING OF STEEL: METHOD, POST-PROCESSING TREATMENTS AND PROPERTIES

Asaf Levy ¹ Aslan Miriyev ² Niyanth Sridharan ³ Tianyang Han ⁴ Eran Tuval ¹ Suresh Babu ³

¹Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel
²Department of Mechanical Engineering, Columbia University, New York, New York, USA
³Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, TN, USA
⁴Department of Mechanical and Aerospace Engineering, Ohio State University, Columbus, OH, USA

Ultrasonic additive manufacturing (UAM) was applied to fabricate laminated carbon steel structures. The feasibility of UAM to manufacture carbon steel samples was proven. Interface investigation of the UAM parts was conducted by SEM, EBSD and TEM analysis. Multiple defects at the interfaces of the as-printed parts were observed. In order to improve the structural homogeneity and mechanical properties of the parts, spark plasma sintering (SPS) and hot isostatic pressing (HIP) post-treatments were applied. As a result, after both treatments, interface defects were healed and the shear strength of the welding interfaces was significantly improved. Treatment by SPS apparatus showed higher shear strength improvements as compared to the HIP-treated specimens.