Method and apparatus for producing a metal wire coated with a layer of metal alloy

A method for producing a coated steel wire, said wire comprising a steel core and a coating layer made of a metal alloy material having a composition comprising at least one first metal component and at least one second metal component, comprising the steps of:

• a) conveying the steel core along a predetermined path in a substantially continuous manner through a first and a second vacuum deposition chamber, said path comprising at least one forward length and at least one backward length spaced apart by a predetermined distance, the at least one forward length and the at least one backward length being substantially parallel with respect to one another, the first vacuum deposition chamber comprising a first group of cathodes, and the second vacuum deposition chamber comprising a second group of cathodes;
• and
• b) during said conveying of the steel core in a substantially continuous manner through the first and second vacuum deposition chambers:
• i) while the second group of cathodes is maintained in a stand-by mode, co-sputtering at least a first powered cathode made of said first metal component and at least a second powered cathode made of said second metal component onto the steel core being moved along said predetermined path, the first and the second powered cathodes belonging to the first group of cathodes;
• ii) when the first group of cathodes is consumed, co-sputtering at least a third powered cathode made of said first metal component and at least a fourth powered cathode made of said second metal component onto the steel core being moved along said predetermined path, the third and the fourth powered cathodes belonging to the second group of cathodes;
• and
• iii) adjusting the power provided to at least one of said first, second, third, and fourth cathodes.