A common task in engineering - to permanently and hermetically join two or more components (such as attaching flanges to bellows expansion joints) - is often accomplished by welding, brazing or soldering.
However, this becomes challenging, costly or impossible when:
One of the articles being joined is made of a material that can not be welded and/or soldered
The presence of solder in the joint is unacceptable
An item is too thin for welding
One of the items is non-metallic
Adhesives can be used in such cases, but then the joint does not provide electrical or thermal conductivity, and often is not as durable and mechanically strong as a metal-to-metal joint.
Electrojoining is an electroforming-based joining technique in which two or more items are permanently and hermetically bonded together by a tightly adherent electroplated layer. Exceptionally strong mechanically, such joints, when properly executed, are also air- and helium-tight, and have excellent thermal and electrical conductance.
The added benefits of this joining method (also known as 'cold welding') are:
Low (<120°F/50°C) temperature of all operations - no heat affected zone that compromises metal strength after welding or brazing
A choice of materials that can be used in the joint - NiColoy®, Nickel, Copper, and their combination
Electroforming and electrojoining can be performed simultaneously, reducing the cost of assemblies
Components being joined can be accurately aligned prior to electroforming, eliminating the need for additional fixturing and machining
Ability to join dissimilar or non-conductive materials that are impossible to weld, solder or braze
Ability to hermetically join very thin (.001"/25 micron) components - bellows, electroforms, diaphragms, membranes, etc.