While high-priced super cars are the biggest beneficiaries of advances in the use of 
lightweight carbon-fiber, car companies are looking to find weight savings across their model lines. As they do so, efforts to find effective bonding solutions for dissimilar materials will become critical.
Recent discussions by automotive engineers and composite material makers at automotive conferences focus on the difficulties in managing disparate thermal expansion rates where aluminum expands at a much higher rate than carbon fiber. There are even slight differences between mild steel and fiberglass options that can impact the construction process.
One way to improve the process is create resins that can increase properties of strength regardless of temperature and other environmental conditions. At the same time, while many automakers use adhesives that can accommodate different coefficients of thermal expansion, they may not offer the same shear and tensile strength as dissimilar material bonding materials and that must be accounted for in any automotive design from super cars to hybrids that can take advantage of weight savings. It is one area where lead-free solders designed to be used in low-heat joining may provide a significant benefit.
The end result could provide benefits to millions. Motorsports teams operate on the adage that “less weight equals more speed” but in the consumer market, concerns about fuel efficiency are king. There are relatively few options that automakers have to accomplish this: make cars more aerodynamically friendly, reduce mass, improve engine efficiency and add hybrid technologies. While there is consistent improvement in maximizing the fuel efficiency through engine design there is a natural limit since it is often done through increased compression ratios of the air-gas mixture that can stress engine components.
On the other hand, lighter-weight materials, especially alloys and carbon fiber, are increasingly the first materials under consideration for a wide variety of vehicle components. As costs come down, the next step will be to find ways to join these materials on a large-scale basis so that it is cost-effective for manufacturers in assembly lines for every model rather than just a select few.
More information on developments in carbon fiber technology are available at Design News. One potential solution to the issue of joining aluminum components via welding is found at Phys.org News.
S-Bond Technology has extensive experience with structural soldering and brazing and offers its expertise to companies with prototype or production needs. – See more at: https://s-bond.com/solutions-and-service/soldering-assembly-services/#sthash.pxlQf6R3.dpuf