Ensuring Manufacturing Infrastructure Readiness Dr. Paul E. Krajewski General Motors Company GALM 2013
Outline Define Scope of Problem Key Questions Material Product Development Forming Assembly / Joining Painting Execution Summary
Back to the Future 1909 Ford Model T Touring Car Aluminum Hood, 1915 Model T
It is difficult to define manufacturing lightweighting approaches.
Audi A8 http://media.windingroad.com/autos_db/lists/3- Aluminum_Space_Frame_jpg_667x667_q100.jpg
Plastics Omnium http://www.scoop.it/t/evolution- et- inovation- auto
MIXED MATERIALS SOLUTIONS
ATS Material Selection Mild Steel Bake Hardenable HSLA Dual Phase Martensitic PHS Al
BMW i3 & i8 Carbon Fiber Aluminum http://www.eurocarnews.com/media/pictorials/1483/7130.jpg
Audi Mixed Materials Aluminum Carbon Fiber
Key Light- weighting Questions Need to define overall strategy What vehicle segment / price point / volume? What is the value of mass on the program? Global or regional execution? Which materials and parts? Where will parts be produced? Make vs. Buy What assembly / joining technique will be used?
Manufacturing Value Stream
Material Raw material availability geography Conversion to sheet / extrusion / ingot Preparation for forming pretreatment Blanking vs. Coils http://en.wikipedia.org/wiki/file:extruded_alumini um_section_x3.jpg
Key Material Issues PHS Prototype infrastructure Material suppliers with Zn coating Aluminum Heat treat capacity Structural casting infrastructure Magnesium Limited supply base for low cost sheet and HPDC 90% of material produced in China Composites Low density SMC Class A / Painting Dimensional stability / fit Carbon Fiber Overall Industry capacity low. North American supply base limited.
Lightweight Material Capacity Aluminum 2012 NA capacity for heat treated Al sheet 90kT. An AIV with 400,000 APV requires 90 kt. Carbon Fiber A carbon fiber intensive body and closures at 200,000 APV would consume global fiber capacity.
Product Development Issues Overall lack of experience with lightweight materials. Lack of design for manufacturing (DFM) information. CAE database for materials and joints. Opportunity for industry collaboration Develop best practices. Acoustic management.
Primary Forming PHS Hot forming lines required Typically done in supply base Aluminum Can use existing steel infrastructure Need more dies (5-6) different lubricants. Scrap segregation Magnesium Requires thermal assisted forming Die casting infrastructure limited. Composites SMC supply base limited. Long cycle time Improved formability compared to steel/al Carbon Fiber North American supply base limited Long cycle time
Need to develop new processes to enable mixed material vehicle executions. Decide whether performing in- house or at suppliers Accurately forecast usage to assure capacity
Form Press Hot Tool Cleaning Robot Form Tool Destack Robot Operator Station & Ergonomics Exit Conveyance Cooling Fixture Location Press Automation Blank Pre-Heater Blank Presentation Fixture Blank Stack
Secondary Forming Trimming Clinching Hemming AZ31 Magnesium BENDING MAGNESIUM FOR AUTOMOTIVE
Assembly / Joining PHS Need new welding, fastening and bonding techniques Aluminum Spot welding compatible with steel? Riveting Adhesive bonding without pretreatment Magnesium Need heated clinching / fastening Corrosion isolation. Composites/Carbon Fiber Closure assembly at Tier supplier Need bonding / fixturing experience Surface effects / read- through
Painting Aluminum and PHS can be processed through conventional paint lines. Al / Steel mix can require varying phosphate bath chemistry Paint bake temperature can affect aluminum properties and will affect composites. Magnesium need to be coated prior to painting/assembly Composites usually painted offline and installed in General Assembly.
The easiest approach to enabling the use of lightweight materials is a dedicated plant.
Bowling Green Assembly
Corvette Z06 Hydroformed Al Roof Bow Mg Roof Frame Ti Valves and Connecting Rods Mg Engine Cradle Hydroformed Al Frame Rails Carbon Fiber Floor Pan
Corvette Stingray
Aluminum Frame
Tube Hydroforming
Composite Painting
Corvette Assembly
Camaro
Camaro ZL1
Global Multi- Plant Platform Key Issues/Questions: Common execution or regional variation Model changeover strategy Are multiple architectures built in same plant Dedicated or flexible body shop
Summary The increased use of lightweight materials will require capital investment and increased piece cost. Impact can be minimized with clear strategy and long term vision. A long term strategy is essential to making sure the value chain is ready for execution.