Changes

During horizontal welding the wire or profile contact material is fed at a shallowangle to the carrier strip material ''(Fig. 3.10)''. The cut-off from the wire or profileis performed either directly by the electrode or in a separate cutting station. Thishorizontal feeding is suitable for welding single or multiple layer weld profiles.The profile construction allows to custom tailor the contact layer shape andthickness to the electrical load and required number of electrical switchingoperations. By choosing a two-layer contact configuration multiple switchingduty ranges can be satisfied. The following triple-layer profile is a good examplefor such a development: The top 5.0 μm AuAg8 layer is suitable to switch drycircuit electronic signals, the second or middle layer of 100 μm Ag/Ni 90/10 isused to switch relative high electrical loads and the bottom layer consists of aneasily weldable alloy such as CuNi44 or CuNi9Sn2. The configuration of thebottom weld projections, i.e. size, shape, and number of welding nibs or weldrails are critically important for the final weld quality.

[[File:Horizontal profile cut-off welding (schematic).jpg|right|thumb|Horizontal profile cut-off welding (schematic)]] The cut-off from the wire or profile is performed either directly by the electrode or in a separate cutting station. This horizontal feeding is suitable for welding single or multiple layer weld profiles. The profile construction allows to custom tailor the contact layer shape and thickness to the electrical load and required number of electrical switching operations. By choosing a two-layer contact configuration multiple switching duty ranges can be satisfied. The following triple-layer profile is a good example for such a development: The top 5.0 μm AuAg8 layer is suitable to switch dry circuit electronic signals, the second or middle layer of 100 μm Ag/Ni 90/10 is used to switch relative high electrical loads and the bottom layer consists of an easily weldable alloy such as CuNi44 or CuNi9Sn2. The configuration of the bottom weld projections, i.e. size, shape, and number of welding nibs or weld rails are critically important for the final weld quality. Because of high production speeds (approx. 700 welds per min) and thepossibility to closely match the amount of precious contact material to therequired need for specific switching applications, this joining process hasgained great economical importance.