A Study of Intermetallic Compound Development In Nickel-Tin Interfacial Zones

Abstract

AbstractInterdiffusion and intermetallic formation in Ni-Sn interfacial zones are examined by X-ray diffraction in samples prepared by electroplating of Sn at room temperature. For the case of plating directly onto electropolished nickel, only very sluggish formation of Ni3Sn4 was observed at 190 C. In contrast, when the nickel surface is chemicaly or chemically-abrasively activated prior to plating, a thin layer of Ni3Sn forms at the initial interface at room temperature, and subsequent annealing at 100 and 190 C produces all intermetallics predicted by the equilibrium phase diagram including Ni3Sn, indicating that the absence of Ni3Sn usually observed arises from its failure to nucleate.