METHOD FOR PRODUCING METAL MATERIAL AND METAL MATERIAL

摘要

A silver wire that has gone through final plasticity processing is heated to a treatment temperature (T1) that is 700ºC or higher but less than the melting point of the silver wire. Then, while the silver wire is maintained at the treatment temperature (T1) of 700ºC or higher but less than the melting point of the silver wire, atmosphere exchange is repeated three or more times by evacuating the gas surrounding the wire to produce a vacuum atmosphere and then feeding helium gas and hydrogen gas to produce a mixed atmosphere. The silver wire is then annealed for a time period that is at least twice the total of the time period for the heating step and the time period for the heating maintaining step. As a result, the entire silver wire can be recrystallized to a coarse texture such that helium and/or hydrogen molecules are filled in the grain boundaries of the recrystallized grains. It is therefore possible to impart high conduction efficiency to the silver wire.