The aluminum castings in the MMLV are left and right versions of the shock tower, kick down rail, hinge pillar and mid rail.
is determining the joining methods between parts made in different metals. Contact between bare aluminum and steel can lead to galvanic corrosion, so mitigation strategies needed to be devised. Two aluminum-steel joining methods were used in the construc- tion of the MMLV. In the traditional method used, an adhesive/sealant elec- trically isolates the materials (typically galvanized steel panels and hard-coat anodized aluminum casting surfaces) prior to being joined using self-piercing rivets. Te protruding end of the rivet also is sealed. Afterward, the assembly is submerged in a phosphate bath and e-coated. In the alternative method, the steel components are e-coated and the aluminum castings are hard coat anodized before the adhesive is applied and the parts are connected with self- piercing rivets. In this case, a phosphate and e-coat treatment is not required after assembly. “Going to an all-aluminum vehicle
structure is expensive,” Conklin said. “But with a bimetallic structure, every joint needs an adhesive barrier, and every joint has self-pierced rivets because you can’t spot weld steel to aluminum.” Te joints are more complicated,
but incorporating aluminum extru- sions and castings with some thought- fully located steel frames leads to a reduction of parts. “Fewer parts to design means fewer tools to manufacture and less labor to join the parts,” Skszek said. “Te num- ber of parts has a cumulative effect. Less parts, means less bodies to make the parts and less assembly costs. It’s a gain in efficiency.” Te MMLV body-in-white design
consists of 32 fewer components (12% reduction) than the baseline vehicle.
Next Steps Te MMLV is a concept car. It
won’t go into volume production, and Ford has not adopted the design for future Ford Fusion models. But the program has successfully served as a showcase of the weight reducing possibilities achievable with existing materials and processes. “All of the aluminum diecast
The MMLV kick down rail replaced five steel stampings and is about 25% lighter.
applications demonstrated with the MMLV are being implemented with other customers,” said Randy Beals, global engineering specialist-casting, Cosma International. Te opportunity to design a car from the ground up for a customer
will probably not present itself to suppliers like Magna, but the increase in application of an aluminum casting in a structurally significant area of the vehicle is promising. “OEMs designing a new vehicle
still set their weight targets,” Conk- lin said. “Based on their targets and requirements, we try to figure out the best location and application of cast- ings where we feel we can get the best bang for our buck.” After the successful creation and testing of the first MMLV concept car, Magna and Ford continued the program with a second version, this time with future concept materials and processes, such as magnesium castings and carbon-fiber parts. Tis version is only a “paper study” and was intended to identify the gaps that have to be addressed to enable use of the new materials as mainstream technology. It also poses another scenario for future research and development: “What if even lighter materials were used to make a vehicle body-in-white?”
MEDIA RESOURCE Using the Actable App, scan this page to watch a video on the aluminum castings in the MMLV. To watch online, go to
www.metalcastingtv.com.
September 2015 MODERN CASTING | 31
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60