Electromagnetic Forming and Joining of Dissimilar Materials PIs: Brad Kinsey, UNH Jian Cao, Northwestern

10. Electromagnetic Forming and Joining of Dissimilar Materials Industrial Need and Relevance: While electromagnetic forming and magnetic pulse welding have shown great promise for improving the manufacturing of difficult to fabricate components (whether less ductile materials or dissimilar materials joining), concerns for implementation in a production environment include coil strength and life. Failure of coil material Failure of insulator material Golovashchenko, JMEP, 2007 NSF I/UCRC Planning Meeting

10. Electromagnetic Forming and Joining of Dissimilar Materials Project Objectives: To advance electromagnetic forming and magnetic pulse welding by increasing the coil strength and address coil life concerns. This could allow the fabrication of workpiece materials not typically accessible to these technologies, e.g., AHSS, due to higher magnetic pressures required. IUL TU Dortmund annual report, 2010 Blakely, Metalworking, 2008 NSF I/UCRC Planning Meeting

10. Electromagnetic Forming and Joining of Dissimilar Materials Approach/Methodologies: Take advantage of electromagnetics in process. Electrical energy is only concentrated on the outer edge of the coil cross-section in the skin depth area. Thus, this is the only location in the cross-section where the highly conductive, lower strength material is required. Credit for this idea is given to Erman Tekkaya’s group at TU-Dortmund, Germany. b.) c.) PST Products (2013) NSF I/UCRC Planning Meeting

10. Electromagnetic Forming and Joining of Dissimilar Materials Normalized current densities Approach/Methodologies: Skin depth calculated from: Typical values ~1-1.5 mm ρ = Electrical resistivity of coil material µ r = Permeability of coil material µ 0 = Permeability of free space (4π×10−7 N/A2) ω = Angular frequency of the circuit (e.g., ω=8.1x104 rad⁄s) NSF I/UCRC Planning Meeting

10. Electromagnetic Forming and Joining of Dissimilar Materials Electroplating schematic Steel base Outer Cu layer Approach/Methodologies: Alternative methodologies to create thin layer on outer edge will be explored, e.g.,: Electroplating Hot dipping Rapid prototyping Direct Metal Laser Sintering schematic (iopscience.iop.org, 2015) Steel substrate Cu additive layers NSF I/UCRC Planning Meeting

10. Electromagnetic Forming and Joining of Dissimilar Materials Approach/Methodologies: Perform cyclic tests with produced coils to assess the coil strength and life. Coil with leads to capacitor back Kamal and Daehn, JMSE, 2007 Coil embedded in epoxy Thibaudeau, MS Thesis 2011 NSF I/UCRC Planning Meeting

10. Electromagnetic Forming and Joining of Dissimilar Materials Deliverables: Coated/plated electromagnetic coils Analyses of coil strength and life Tooling life assessment and predictions Criteria and empirical guidelines Thibaudeau, MS Thesis 2011 NSF I/UCRC Planning Meeting

10. Electromagnetic Forming and Joining of Dissimilar Materials Budget and Timeline: Estimated cost of the project is $150k for 1.5 year. Task / Milestone Year 1 Year 2 Year 3 Q1 Q2 Q3 Q4 Assess means for coil fab.   Implementation of coils Analyses of coil characteristics Coil life and strength testing Guidelines and criteria NSF I/UCRC Planning Meeting

10. Electromagnetic Forming and Joining of Dissimilar Materials Discussion: Are the industrial need and relevance accurately captured? Are the objectives realistic and complete? Are the approaches technically sound and appropriate? Are there alternative implementation paths or better approaches? Are the deliverables impactful to industrial partners? Are the budget and timeline reasonable? Are there conflicts with intellectual property or trade secrets? NSF I/UCRC Planning Meeting