Bonded materials often possess characteristics unachievable in any other way. For example, traditional bi-metal thermostats deform in one direction in response to low temperatures and the other at high temperatures. No unbonded material could have achieved this.
Another bonding success story was the Mongolian composite recurve bow. Horn, bamboo and sinew were bonded with an animal-derived adhesive and strung opposite to their natural curve to store more energy in a smaller package capable of being used on horseback. This adhesive bonding technology came close to conquering the world.
Advantages of Adhesive Bonding
Both metal expansion and archery can subject materials to powerful stresses. To bond diverse materials able to withstand this, designs must avoid stress localisation. Bonds are only as good as their weakest point.
The inherent vulnerability of bonds to localised stress applies to both mechanical bonds and welds. Hinges, bolts, nail-heads, pop-fasteners and zips are all inclined to be failure points, whether we are considering ship construction or tailoring a pair of jeans.
Adhesives are easier to homogenise and spread uniformly across substrates – distributing stresses safely across the total area. Such assembly methods avoid the creation of weak points in the material and disperse the focal points of externally applied stress.
Welding is an imperfect art. It can introduce weak points into materials that weren’t there to start with. This is particularly true of the lighter and thinner materials preferred by modern manufacturing. Moreover, welding and mechanical fastening methods are time-consuming and often overkill for the level of bonding needed.
Adhesive bonding of metals was always an attractive alternative, but for years manufacturers were loathe to try it. Developing adhesives for metal surfaces was difficult. More recently, however, reliable metal bonding adhesive has become available from companies like http://www.ct1ltd.com/product-applications/metal-to-metal-adhesive/.
Metal bonding adhesive allows metal fabrication industries to reap the benefits of composites at last. Composites provide opportunities to reduce a product’s weight, change its electrical properties, provide environmental protection or improve appearance.
Car and aircraft industries are already creating large, light, energy-saving moulded panels from bonded composites. Uptake is also brisk in the oil and gas industry, where the weight of drilling platforms tends to correlate with the cost of the extracted oil. This is particularly true in the construction of the shakers required for shale oil extraction.