| 摘要 |
PURPOSE: Tin-silver coatings to be applied to substrate materials used in electrical and electronic applications, such as in automotive connectors, and a method of applying a tin-silver coating to the substrate materials are provided. CONSTITUTION: The coating is characterized in that it is applied to an electrically conductive material having a melting point greater than 225 deg.C, wherein the coating consisting of more than 1,0 wt% to 20 wt% silver and the balance essentially tin, wherein the silver content in the coating is in the range of from 2,0 wt% to 15 wt%, wherein the silver content in the coating is in the range of from 3,0 wt% to 10 wt%, wherein a hardness is in the range of from 0.32 to 0.41 GPa, the coating is a non-electroplated coating, wherein the coating consists of more than 1,0 wt% to 20 wt% silver, optionally an affective amount up to 5.0 wt% of at least one element selected from the group consisting of bismuth, silicon, copper, magnesium, iron, nickel, manganese, zinc, antimony, and the balance essentially tin, and wherein the at least one element is present in an amount ranging from 0.1 wt% to an amount which does not cause the formation of deleterious oxides. The process for coating a substrate material comprises the steps of providing a substrate material to be coated; preparing a bath consisting of more than 1.0 wt% to 20 wt% silver and the balance essentially tin; and immersing the substrate material in the bath to form a coating layer on the substrate material, which coating layer consists of more than 1.0 wt% to 20 wt% silver. |
