GM Advanced Mixed-Metal Bonding

Cadillac will be the first to use the companies best solutions to mate aluminum alloys to various steels for a lighter weight and stiffer structure.

Wayne Gerdes - CleanMPG - Jan. 22, 2015



Advanced lightweight alloys of different compositions can now be joined without worry of galvanic corrosion or bond strength and durability.



At the Washington Auto Show, Cadillac stated it will use the auto industry’s most advanced mixed-material manufacturing techniques to build its upcoming all-new CT6 sedan, allowing the efficiency of a smaller vehicle.



Cadillac’s Weight Loss Program Begins with More Aluminum



The CT6 that goes on sale in the fourth quarter of 2015 will be built at the Volt/ELR’s Detroit-Hamtramck Assembly plant using advanced combination of joining techniques. A new body shop with new tooling and advanced technologies has been added to the plant. The fully automated, roughly 138,000 sq. ft. shop is dedicated to manufacturing the CT6.



GM Pioneers Use of Lightweight Magnesium Sheet Metal



Engineers designed a number of different types of joining methods for dissimilar materials allowing every panel to be designed of a material that meets its needs, not just the needs of manufacturing simplicity.



GM’s New Aluminum Welding Technique is Pretty Slick



Cadillac President Johan de Nysschen:

Quote:

“We have invested $300 million in Detroit-Hamtramck allowing us to advance the art of manufacturing and take craftsmanship and manufacturing technology to a new level.”

The advanced body joining techniques include:

• Patented Aluminum Spot Welding Technology


• Aluminum Laser Welding creating a seamless joint of exterior panels


• Self-Piercing Rivets which join different types of materials together with a clean appearance


• Flow Drill Screws which are able to join different types or materials along with an adhesive

Aluminum arc welding and structural adhesive are also separately used for CT6 body assembly.

Among the five techniques, the CT6’s engineers were able to select the best joining method for a given material combination and body location (for machine equipment access).



To weld both the inner and outer vehicle frames, 28 robots descend on the vehicle body in two separate framing stations, joining the body-in-white together from all angles. The robots are mounted above and beside the vehicle and can also reach beneath it. The two framing processes were choreographed to compensate for different microscopic vibrations, and CT6 body construction resembles an orchestra as the robotic arms move in and out around the vehicle.



Once the body construction is complete, a large robotic arm lifts the entire vehicle from one part of the assembly line to an upper-level conveyer – unheard of for a vehicle the size of CT6 – to be transferred across the Detroit-Hamtramck plant.



Using these advanced manufacturing techniques allows for the CT6 to meet the highest quality standards and allows Cadillac to use the most mass-efficient materials while reducing fuel consumption and enhancing safety and driving dynamics.

GM Advanced Mixed-Metal Bonding