Electric contact having a multilayered coating structure
An electric contact includes a multilayered coating structure. The multilayered coating structure includes an intermediate layer and a top layer arranged on top of the intermediate layer. The intermediate layer includes Bi 3 Ni and the top layer includes a plurality of free bismuth grains.
1 . An electric contact, comprising:
a multilayered coating structure including an intermediate layer and a top layer arranged on top of the intermediate layer, the intermediate layer consists of Bi 3 Ni and the top layer includes a plurality of free bismuth grains, a shear resistance of the top layer is increased by an adhesion of the top layer to the intermediate layer.
2 . The electric contact of claim 1 , wherein the electric contact is a press-fit contact.
3 . The electric contact of claim 1 , wherein the plurality of free bismuth grains have an average grain size of about 10 nm to about 0.5 μm.
4 . The electric contact of claim 3 , wherein the top layer has a thickness of about 0.2 to about 5 times the average grain size of the free bismuth grains.
5 . The electric contact of claim 4 , wherein the thickness of the top layer is about the average grain side of the free bismuth grains.
6 . The electric contact of claim 1 , wherein the plurality of free bismuth grains have a main crystallographic orientation of (0 1 2).
7 . The electric contact of claim 1 , wherein the top layer is an outermost layer of the electric contact.
8 . The electric contact of claim 1 , wherein a thickness of the top layer is between about 2 nm and about 1.0 μm.
9 . The electric contact of claim 1 , wherein a thickness of the intermediate layer is at least 50 nm.
10 . The electric contact of claim 1 , wherein the top layer is at least about 90% free bismuth grains.
11 . The electric contact of claim 1 , wherein the multilayered coating structure does not contain tin.
12 . The electric contact of claim 1 , wherein the intermediate layer is formed from a nickel layer interacting with a second layer disposed on the nickel layer and including the free bismuth grains, the nickel layer has a thickness that is less than a thickness of the intermediate layer.
13 . A method of manufacturing an electric contact having a multilayered coating structure, comprising:
applying a first layer of nickel to the electric contact; and
applying a second layer of bismuth on top of the first layer of nickel, a thickness ratio of the first layer to the second layer is at most 1:9, when the second layer is applied on the first layer, an intermediate layer consisting of Bi 3 Ni is formed from the first layer and a portion of the second layer, and a top layer including a plurality of free bismuth grains is arranged on top of the intermediate layer, a shear resistance of the top layer is increased by an adhesion of the top layer to the intermediate layer.
14 . The method of claim 13 , wherein the thickness ratio of the first layer to the second layer is between 1:9 and 1:100.
15 . The method of claim 13 , wherein a thickness of the first layer is between about 1 nm and 0.1 μm.
16 . The method of claim 13 , wherein an average grain size of the first layer is between about 1 nm to about 50 nm.
17 . The method of claim 13 , wherein at least one of the first layer and the second layer is applied by at least one of an electroplating, a physical vapor deposition, and a chemical vapor deposition process as a single process or as a two-step process.
18 . The method of claim 13 , wherein the intermediate layer has a thickness greater than a thickness of the first layer, a top layer formed from the second layer is disposed on the intermediate layer and has a thickness less than the thickness of the intermediate layer.