Triplate®: The Ultimate Aluminum-Steel Welding Solution
For years, shipbuilders have been seeking a solution to the corrosion of metal joints that occurs over time. The vastly different coefficients of thermal expansion between steel and aluminum causes traditionally welded joints to deteriorate. Even traditional explosion welded transition joints are subject to oxidization, brittleness, and cracking caused by exposure to seawater.
Triplate®, a bonded construction material manufactured from three homogenously bonded metal layers, has emerged as the leading intermediate material to join aluminum and steel in corrosive environments. Its three bonded layers — a steel base, a pure aluminum center, and a corrosion-resistant aluminum layer — form a stronger and much more durable union than traditional bolting and riveting techniques.
The secret to Triplate’s® superior joint strength properties and corrosion resistance is the vacuum explosion welding process. Instead of using atmospheric explosion-welding, which enables the formation of oxide agglomerations on the metals, Triplate® is vacuum-clad. The use of a vacuum chamber, and, the consequent preclusion of air, allows for use of less violent explosives. This process results in a smoother bond between the metals.
To create this 100% dense, homogenously bonded product, spacers are placed between the metal plates. The controlled explosion causes the plates to become super-plastic, which breaks up the oxide atoms on metals’ surfaces. Pressure accelerates the top plate down at an ultra-high velocity until it is clad into the bottom plate, and a new atomic bond is formed.
The result is Triplate®, manufactured in sizes that can be waterjet cut and formed in a variety of ways to accommodate most applications in corrosive environments. While Triplate® is stocked in standard sizes (four times the thickness of the aluminum plate is the recommended width), custom shapes and sizes are available from production with short lead times.
Unlike traditionally welded joints, Triplate® remains straight and intact even when exposed to elevated temperatures. Additionally, as proven through the MIL-J-24445A inspection procedure, the vacuum-clad material will resist the effects of corrosion such as surface fissures, undercuts, laps, or oxide agglomerations when exposed to liquids with high capillary activity, like seawater.
Welding aluminum alloys directly to carbon steel is not possible through traditional welding methods. Using Triplate® as an intermediate between the metals has revolutionized how aluminum and steel can be joined together for shipbuilding and marine applications.
To read more information about how to incorporate Triplate® into your next project, please contact us today.