Meridian Lightweight Technologies Inc. COST SAVING ON MAGNESIUM DIE-CASTING CONCEPT USING OPTISTRUCT November 3 & 4 th, 2009
Meridian Lightweight Technologies MPD Strathroy, ON Global Technology Centre Strathroy, ON MTUK Bus. Dev. & AE Nottinghamshire, UK MPD Plant E Strathroy, ON MPA Eaton Rapids, Mi Bus. Development Brentwood, Tennessee Bus. Dev. Bordeaux, France Bus. Development AE & Program Mgmt. Plymouth, Michigan Bus. Dev. & A.E. Turin, Italy Bus. Dev.,AE & Program Mgmt. Heidelburg, Germany MPI Verres, Italy Business Development Tokyo, Japan SMMP Bus. Dev. CMBM Shanghai, China Chongqing, China
Magnesium - overview Magnesium is the eight more abundant element on the land surface and represents approximately 2.5% of its composition. Because of its remarkable reactivity, it is not found in nature to the metallic state, but like compound marine waters contain approximately 0.13% of magnesium hence a cubic meter of marine water contains 1.1 kg of magnesium Other common sources are dolomite ((CaMg)CO3), magnesite (MgCO3) and carnallite. Two processes to produce primary metal are currently in use thermal reduction of magnesium oxide electrolysis of molten magnesium chloride Magnesium is the lightest among structural alloys. With a density of 1,78g/cm3 30% lighter than aluminium 75% lighter than steel Pure magnesium does not awaken interest for industrial applications; instead magnesium alloys are widely used especially in automotive and aeronautical industries. Magnesium castings could be in competition with steel, aluminium and plastic
Magnesium vs. other materials Compared with stamped and welded steel: Magnesium is 75% lighter Casting technology allows component consolidation and integration: there is no necessity of welding and assembly (lower cost assembly) Tooling costs are significantly lower Complicated thin-walled near-net-shape monolithic parts can be produced Magnesium allows superior dimensional stability/repeatability Compared with aluminium die-castings: Magnesium is 33% Lighter Magnesium offers higher machinability Longer Die Life Thinner walls and Larger thin-walled near-net-shape casting Greater general corrosion resistance Higher damping capacity (NVH) Higher elongation without heat treatment and greater energy absorbing capabilities (CRASH) Compared with plastic: Higher mechanical properties and superior stiffness Greater energy absorbing capabilities (CRASH) Higher temperature applications Higher damping capacity (NVH) Higher electromagnetic shielding properties On the other hand, magnesium alloys present some weaknesses: elastic modulus is low if compared to other structural metals resistance to galvanic corrosion (magnesium is anodic to most of the other engineering materials) common magnesium alloys have lower high temperature properties than aluminium alloys and steel
Main automotive magnesium components Transfer Case Front End Structures Transmission Case Cam Covers Center Console Engine Cradle 3 rd Row Seat Frames Instrument Panel Seat Back/Seat Cushions Header Bow Steering Column Brackets Steering wheels cores
Meridian CAE led design in the Product lifecycle Historical approach Without CAE CAD Tooling Tests CAD Tooling Tests CAD Tooling Tests CAD led design CAD CAE Tooling Tests CAE CAE led design CAE CAD Tooling Tests CAE Design process CAE LED DESIGN ADVANTAGES Significantly reduction of time to deliver the concept. CAE model can be provided in advance to customer to verify structural performance. Simple rough midsurface iges model can be provided for package checks. NO initial CAD design needed (NO internal CAD resources in Meridian)
CAE methodology INPUT FROM CUSTOMER : DESIGN SPACE BOUNDARY CONDITIONS TARGETS Topology and free size OPTIMISATION 2 weeks INITIAL CONCEPT CAE model can be provided to the customer for full scale analysis ROUGH CAD 10 min ~ 6 weeks Rough CAD (iges) for package checks, design review and cost evaluation 2 weeks for a first concept 3D CAD
Actual Meridian methodology Only weight optimisation 20 18 16 Cost (Euro) costo [Euro] 14 12 10 8 6 4 2 0 0 1 2 3 4 5 6 7 8 9 10 Peso [kg] Weight
New approach 20 18 Cost costo [Euro] (Euro) 16 14 12 10 8 6 4 2 0 0 1 2 3 4 5 6 7 8 9 10 Peso [kg] Weight (kg) Part cost (Euro) 900ton 1500ton 2500ton 3200ton Projected area (mm2)
Example: Instrument panel INITIAL DESIGN SPACE BOUNDARY CONDITIONS TARGET: First vertical mode > 37.5Hz Mass fixed 6 dof
Actual Meridian methodology Topology opt Design space Ribs from topology opt Free size opt CONCEPT A: Weight: 2.75kg NVH: 37.5 Hz Area ~200000 mm 2 die-cast machine 2500ton Shape opt
New approach Model parameterisation: the projected area now is a project variable Shape variables are created taking into account the design space Shape optimisation with a constraint on the projected area
New approach OPTIMIZED SHAPE Topology opt FINAL CONCEPT Free size opt CONCEPT B: Weight: 2.1kg NVH: 37.5 Hz Area ~109000 mm 2 die-cast machine 900ton
Results CONCEPT WEIGHT (kg) PROJECTED AREA (mm 2 ) DIE CAST MACHINE (ton) ACTUAL MERIDIAN METHODOLOGY 2.75 197000 2500 ton CONCEPT A NEW APPROACH (first concept) 3.03 150000 1500 ton CONCEPT B NEW APPROACH (second concept) 2.1 109000 900 ton CONCEPT C
CONCLUSIONS AND NEXT STEPS ADVANTAGES Lower production costs due to projected area optimisation Weight reduction (?) Possible cost savings taken into account new parameters design for different die-casting machines die-casting machines availability design for dual cavities productions More opportunities to optimise concept Minimise not just weight, but the cost function NEXT STEPS Design for function to be closer to car makers demands Create automatic tools to implement the methodology on all the components