| 摘要 |
PURPOSE:To prevent evaporation and scattering of the metallic fume from a base material metal having a high vapor pressure in the stage of a heat treatment after cladding by plating Ni over the entire surface of the base material except at least the part to be clad then cladding a noble metal (alloy) material thereon. CONSTITUTION:Ni is plated 2 over the entire surface of both top and bottom surfaces as well as both right and left side surfaces of a belt-like base material 1 consisting of, for example, German silver shown in the figure (a). While such plated material 1 is moved at a prescribed speed in an electric furnace of a mixed gaseous atmosphere of H2 and N2 held at about 600 deg.C, a noble metal material 3 consisting of Ag-Pd formed into a tape shape is clad on said material as shown in the figure (b). Such clad material is repeatedly subjected to rolling and annealing at about 650 deg.C and a clad material 4 shown in the figure (c) is obtd. There are no evaporation and scattering of the metal which is the base material having a high vapor pressure in this process for production and therefore the decrease in the joint strength that may arise from sticking of the metallic fume to the surface to be clad with the noble metal material and the surface of the noble metal material and the exfoliation of the noble metal material arising therefrom are prevented. |
