AbstractA Swiss organization has developed a process for joining of aluminum and its alloys resulting in a joint strength close to the base material, exceeding existing techniques (such as welding, brazing and bonding) by a factor of 2 and more. They now look for partners in the automotive, aerospace, utility or manufacturers of metal packages in the food industry to industrialize this technology.
DetailsOwing to its low specific weight and high corrosion resistance, aluminum and its alloys are a widely used material for the design of products and systems in weight critical applications such as for aerospace and automotive parts. Given the rising costs for fuel and the global aim to reduce emissions, the importance of light weight materials and corresponding design and joining concepts increases.
Aluminum’s high corrosion resistance is due to its natural formation of a solid oxide layer. However, aluminum forms a tenacious oxide layer. It is impossible in practice to stop it from oxidizing at exposed surfaces. It can nevertheless be welded because the oxide can be dispersed by the action of a welding arc, although fragments of oxide may become entrapped into the weld. However, this results in low mechanical properties.
Transient liquid phase (TLP) bonding uses a metallic interlayer, either in the form of a thin foil or a coating on the base material. The assembly is then heated to a temperature in the vicinity of the aluminum-interlayer eutectic temperature. The diffusion of the interlayer into the aluminum substrate therefore induces melting, but the liquid solidifies isothermally as homogenization occurs and the liquidus temperature rises. The assembly can then be heat treated to achieve maximum mechanical properties.
The technology developed by the Swiss organization - a development partner for new technologies and products - for joining of aluminum and its alloys and based on the TLP bonding offers engineers and designers the possibility to design products with high strength while minimizing the use of material. Main applications may be found but are not limited to the Aerospace, Automotive, Food, Construction and Sporting Goods Industry.
Achieving joint strengths close to base aluminum material. Exceeding existing joining techniques such as bonding with adhesives by a factor of >10, brazing and welding by a factor of >2.
Minimized use of material.