Fusing and bonding furnaces are utilized to join high-strength and refractory metals – those that are either difficult or impossible to weld. The bonding process involves applying high temperature and pressure to similar or dissimilar metals fused together in a hot press, which causes the atoms on solid metallic surfaces to intersperse and bond. Unlike traditional brazing techniques, the resulting bond exhibits the strength and temperature-resistance of the base metals. It also eliminates the need for filler material that affects the final weight and dimensions of the mated metals.
Recent advances in the diffusion-bonding industry have led to the development of vacuum hot-press systems that include gas-quench cooling capabilities with internal heat exchangers. These Rapid cooling quench systems improve the bond, increase output and significantly increase cycle time, while also allowing for optimal post-bonded heat treatment.
In vacuum hot-press diffusion bonding, vacuum levels can be reduced near to, or just below, the boiling point of any of the major alloy constituents present in the materials being processed. These Specialized furnaces feature integrated presses to provide superior control of pressure and temperature. Diffusion bonding is also being utilized for an additive-manufacturing process called laminated-object manufacturing (LOM). In this approach, thin sheets of metal are bonded together in what is essentially an additive process.
Whether applied in layers or simply to bond two parts, diffusion bonding is a suitable process for joining refractory and other high-strength alloyed materials together without the need for brazing.