September 13, 2011 Rich Tenaglia Engineering Manager, Materials and Ultrasonic Processing

1. Overview of Industry Trends and Needs for Dissimilar Materials Joining September 13, 2011 Rich Tenaglia Engineering Manager, Materials and Ultrasonic Processing Email: rtenaglia@ewi.org Phone: 614.688.5241

2. Introduction Present an overview of the key drivers for dissimilar materials joining applications in various industries. Major reasons why dissimilar material joints are needed include: • Lightweight structures • Structures with locally tailored properties • Corrosion resistance • Economical use of valuable alloys • Thermal management and electrical conductivity • Innovative product designs and functionality • Cost reduction

3. Why is detailed info about DMJ hard to find? Lots of articles referring to use of dissimilar materials, many about modeling and sanitized research about joint properties and testing. But case studies and details about specific joining process parameters, part designs, joint geometry, costs, and overall performance benefits are almost always missing. Why??

4. Why is detailed info about DMJ hard to find? Number of Publications from 1970 to 2008 Related to Different Materials Including DMJ

5. DMJ Needs by Industry

6. Why is detailed info about DMJ hard to find? Developing a successful dissimilar materials joint is often crucial to the technical and commercial success of a product and is therefore held as proprietary and often viewed as intellectual know-how. Achieving a successful dissimilar materials joint often requires a significant amount of development work and testing; few companies wish to share at no cost with their competition.

7. Why all the interest in DMJ? We just have to get our quality up, but our costs down! We’ve squeezed about all the cost and performance we can from our existing product. We need innovative products to keep up with our competition! Materials cost so much these days!!…..Cr, Ni, Cu, rare earths…almost everything!

8. Aerospace - Structures Opportunities to use different aluminum alloys/tempers for upper and lower wing skins, stringers, and spars. Each structural part has different strength, formability, and corrosion-resistance requirements. Solid-state joining techniques being developed to eliminate costly riveting.

9. Aerospace – Engines/Blisks Opportunities to use different alloys for hub (stress rupture) and blades (deformation and creep resistance) Components with better high temperature properties for increased operating efficiency Design for repair and blade replacement Source: MTU Aero Engines, GmbH

10. Aerospace Emerging developments for DMJ inertial friction welding for blisk stages, moving from titanium alloy fan blisks to nickel-based hot stages. Source: MTU Aero Engines, GmbH

11. Automotive and Transportation Mazda MX-5 aluminum trunk lid and steel bolt retainer joined by friction spot welding 2012 Audi A6 featuring aluminum and steel construction Trends toward dissimilar metal joining driven by weight reduction efforts to drive toward new CAFE standards. Renewed challenges for prevention of galvanic corrosion.

12. Batteries – Hybrid Vehicles Numerous emerging designs for lithium-ion batteries Dissimilar material joining challenges for electric, hybrid, and plug-in hybrid electric vehicles. Complex material combinations with special needs including: High production throughput and process robustness, cost reduction, long-term service durability, consistent performance, and improved NDE methods for quality assurance.

13. Heavy Transportation Fuel-efficient freight transportation Aluminum-steel rail freight cars Fuel-efficient municipal vehicles Rising costs of fuels driving needs to lightweight construction; aluminum and composite parts joined to steel and stainless structures.

14. Alternative Energy Production DMJ driven by the nature of the system components and functional needs for thermal management and electrical conductivity. Wind: High-power transients present thermal management challenges in electrical conversion equipment; various combinations of metals, ceramics, glass, and composites are used. Thermal Management: Al-Cu and Al-SiC joints finding extensive application in the bonding of cold plates, vapor chambers, heat sinks, and other thermal management components. Sensors: Sensors and sensor housings often require metal-to-metal and/or metal-to-ceramic bonds that make electrical connections or hermetic seals. Solar: Bonding metallic conductors to silicon and glass (coated and uncoated) panel surfaces, ideal for joining of conductors and dissimilar material heat sinks for thermal management. Images courtesy of S-Bond Technologies

15. Medical Growing trends in endoscopic, less-invasive surgical techniques. Growing trend in single-use, pre-sterilized surgical tools. Microjoining of expensive titanium and stainless steel parts that are invasive to less expensive, stronger steels for non-invasive portions of devices.

16. Electronics and Telecommunications The ever increasing need for bandwidth and speed are driving the use of higher powered electronics in telecommunications in local broadcast vans, cell towers, central servers, and satellites. High-power electronics often require unique thermal management systems, including: passive heat sinks, finned heat exchangers, and actively cooled cold plates. A requirement to join Al and Cu parts is common, but emerging applications include joining of graphite, aluminum and silicon carbide (Al:SiC) as weight reduction and increased thermal performance are needed.

17. Oil and Gas X65 Steel pipe with Inconel 625 inner cladding Image courtesy Voest-Alpine New oil and gas production fields face material challenges for arctic or deep, sour gas (H2S-containing) environments. Growing need for lower-cost cladding approaches for corrosion resistance and improved joining of bimetallic riser pipe. Other DMJ needs involve metal-ceramic joining for sensors and housings to guide “smart” drilling systems and wear seals.

18. Summary - Takeaways DMJ is more involved than just a “material combination”… lots to consider….. • Joint design and material thicknesses • Differences in melting temperature • Thermal expansion-contraction mismatch during joining and in service • Fixturing and constraint effects on joining stresses • Formation of brittle intermetallic compounds during joining which may lead to brittle joints • Heating and cooling rate effects on the microstructure of the joint • Needs for pre and post heating • Needs for composite transition materials or special filler materials during joining • Potential for galvanic corrosion problems in service EWI’s experience and knowledge with dissimilar materials joining can help you meet your needs.

19. Questions? Rich Tenaglia Engineering Manager, Materials and Ultrasonic Processing Email: rtenaglia@ewi.org Phone: 614.688.5241