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

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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. 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