FSW and FSSW in the Automotive Industry

Friction Stir Welding and Friction Stir Spot Welding are used in the automotive industry by many original equipment manufacturers (OEMs) and their suppliers.

One of the earliest developments in this sector addressed friction stir welding of 'Tailor Welded Blanks' in 1999 (see video).

Rührreibschweißen von Tailor Welded Blanks

2:42 min, © TWI Ltd, 13 February 2013

Tailor Welded Blanks are flat metal sheets, which first welded from dissimilar materials or varying thicknesses, and subsequently deep-formed to make automotive body panels. In a Group Sponsored Project at EWI in Columbus, Ohio, and TWI in Cambridge, UK, the companies BMW, DaimlerChrysler, GM, Ford, Rover, Tower Automotive and Volvo investigated 1999 friction stir welding for making blanks by welding thin Sheets to thick sheets.

Sheets of 1.5 mm and 3.0mm thickness were clamped side by side onto an jig, which was tilted by 9°. They were welded by a rotating tool, of which the axis was also tilted by 9°. With the large, modular FSW machine FW22 at TWI the door inner panels of car doors were welded in a laboratory environment. These were subsequently deepformed at BMW. They were 1,5 kg or 30 % lighter than those made from conventional steel.

Applications to passenger cars:

Boot lids and doors in Japanese cars
Wheel rims in Australia, China and Norway
Battery tubs in French and German electric car

In lorries:

Tippers and tail gates
Telescopic cranes and ladders of fire engines
Tanks of articulated silo trailers

Published Industrial Applications of FSW in the Automotive Industry

Friction stir welded aluminium panel by Riftec and HAI for the Mercedes SL - R231

The following applictions of using friction stir welding or friction stir spot welding in the automotive industry have been published:

2020 Tesla Model Y (Octovalve and battery box)^[9][10]
2020 Rapid Technic AG for Designwerk AG (battery cooling plates for E-trucks)^[28]
2018 Morgan Aero 8 (Complex HFQ® panel with variable tailored thickness of 3-2-3mm)^[5][6]
2017 TWB Company (tailor welded blanks for Ford door panel inner)
2017 Ningde Tianming New Energy Auto Parts (battery pack box and case)^[22]
2015 Acura TLX (cast-aluminum and steel 'hybrid' front subframe)^[35]
2013 Honda Accord (front subframe)^[1][4]
2012 Mercedes SL - R231 (tailor welded blank and three box profiled floor sections on each side of the transmission tunnel)^[4][7][27]
2012 Land Rover L405 (subframe mounts)^[4]
2012 Benteler (Battery tray for Renault Zoé)^[17][18]
2011 McLaren 12 C (structural part)^[2]
2010 Toyota Prius (rear hatch)^[1]
2008 Delphi Automotive (sealed enclosures and heat exchangers for BMW and Chrysler)^[14]
2008 Fundo Wheels (aluminium wheels for Volvo XC 90)
2007 Riftec for Audi (B-pillar of Audi R8 Spyder)^[1][15]
2006 Mazda MX-5 Miata (trunk and hood)^{[1][23][24][25]}
2005 Ford GT (part of space frame)^[1]
2005 Pierburg (EGR cooler)^[11]
ca 2005 Showa Denko (suspension arms)^[19]
ca 2004 Simmons Wheels and UT Alloy works (aluminium wheels)^[20]
2004 Mazda RX-8 (rear doors and hood)^{[1][8][23][24][25]}
2003 Panoz Esperante (structural part)^[3]
2003 Lincoln Town Car L (suspension components)^[1][21]
2001 Volvo V70 (rear seat frame)^[1]

FSW Development Studies in the Automotive Sector

Lotus Engineering Inc: 2020 Model-Year, Mass-Reduced Crossover Vehicle, 2012

Lotus Engineering Inc. created in 2012 a theoretical model and analyzed the structural and impact performance of a low-mass vehicle body-in-white on behalf and under a contract with the California Air Resources Board (ARB) in a study on 'Evaluating the Structure and Crashworthiness of a 2020 Model-Year, Mass-Reduced Crossover Vehicle Using FEA Modeling'.^[34]

Lotus Engineering developed a vehicle comparable to the 2009 Toyota Venza; this model had equivalent dimensions, utility objectives, and passenger and interior volume. The projected mass reduction for the 2020 model year was 38 % less mass for all systems except powertrain.^[34]

Benchmark: 2009-2011 Toyota Venza

Courtesy of IFCAR, public domain

Lotus created the body of this vehicle model using the exterior styling and other non-body components from the 2010 Lotus High Development vehicle. This was derived from the baseline Toyota Venza, for which low-volume tooling was used due to the Toyota Venza volume of 60,000 units per year.

Friction spot joining (FSJ) was used to join the majority of the aluminum components using a ‘Friction Stir Unit’ that had been developed by Kawasaki Heavy Industries. Key advantages are cost (1/20th of a resistance spot weld), weight (in comparison with rivets or fasteners) and no degradation of the parent material properties (in comparison with fusion welding). The estimated FSJ cycle times are given in the timing sheets of this report, e.g. in Station SA70 (pages A 14 and A37):^[34]

Robot	Process^[34]	Timing	Timing
Robot SA70R10	Drop end effector to storage and pick Friction Stir Unit	16 sec
Robot SA70R10	Friction Stir join 10 locations		10 sec
Robot SA70R10	Friction Stir join 12 locations		12 sec
Robot SA70R10	Friction Stir join 6 locations		6 sec
Robot SA70R10	Drop Friction Stir Unit and pick up end effector	16 sec
Robot SA70R20	Drop end effector to storage and pick Friction Stir Unit	15 sec
Robot SA70R20	Friction Stir 10 locations in station SA70-40		8 sec
Robot SA70R20	Friction Stir 25 locations in station SA70-40		30 sec
Robot SA70R20	Drop Friction Stir Unit and pick up resistance spot welding gun)^{[TBC ?]}	15 sec
Total	Excluding materials handling time	62 sec	66 sec

Keio University: Eliica (Electric Lithium-Ion battery Car), 2003

2003 Eliica (Electric Lithium-Ion battery Car) by Keio University

2015 Tailor welded blanks of 1.2 mm and 2.0 mm thick AA5182-O sheets at 3 m/min by Pacific Northwest National Laboratory, General Motors, Alcoa and TWB Company LLC.
2004 Roof Box Made from Noncombustible Magnesium Alloys by Material Reserch Institute for Sustainable Development, Hyogo Prefectural Institute of Technology and Sakurai Industries Co., Ltd.
2003 Eliica (Electric Lithium-Ion Battery Car) by Keio University