Bi-material strip and a method of bonding strips of different materials together
A continuous hot bonding method for producing a bi-material strip with a strong bond therebetween is provided. The method comprises sanding a first strip formed of steel; and applying a layer of first particles, typically formed of copper, to the sanded first strip. The method next includes heating the first strip and the layer of the first particles, followed by pressing a second strip formed of an aluminum alloy onto the heated layer of the first particles. The aluminum alloy of the second strip includes tin particles, and the heat causes the second particles to liquefy and dissolve into the melted first particles. The first particles and the second particles bond together to form bond enhancing metal particles, which typically comprise bronze.
1. A bi-material strip, comprising:
a first strip formed of steel;
a second strip formed of an aluminum alloy and bonded to said first strip, said aluminum alloy including particles of tin;
an intermediate layer of bronze bonding said first strip to said second strip, said bronze being formed from said particles of tin from said aluminum alloy dissolved in particles of copper, wherein none of said particles of tin from said aluminum alloy are present in a portion of said second strip, said portion of said second strip being located along an entire lower surface of said second strip and adjacent said intermediate layer.
2. The bi-material strip of claim 1 , wherein said intermediate layer is disposed along an upper surface of said first strip, and said upper surface has irregularities formed by sanding.
3. The bi-material strip of claim 1 , wherein said bi-material strip is used in a bearing, bushing, or washer.
4. The bi-material strip of claim 1 , wherein said particles of copper are applied to an upper surface of said first strip before melting and mixing with said particles of tin.
5. The bi-material strip of claim 1 , produced by a process comprising the steps of:
applying said particles of copper to an upper surface of said first strip;
heating and melting said particles of copper applied to said upper surface of said first strip;
applying said second strip to said heated particles of copper such that said particles of tin present in said aluminum alloy of said second strip melt, dissolve into, and bond to said melted particles of copper, and said melted particles of copper and said particles of tin together form said intermediate layer of bronze between said first strip and said second strip.
6. The bi-material strip of claim 5 , wherein the step of applying said second strip to said heated particles of copper includes pressing said lower surface of said second strip onto said heated particles of copper.
7. The bi-material strip of claim 6 , wherein the pressing step includes dissolving said particles of tin into said particles of copper.
8. The bi-material strip of claim 6 , wherein the pressing step includes liquefying at least some of said particles of tin along said lower surface of said second strip.
9. The bi-material strip of claim 6 , wherein the pressing step includes feeding said first strip and said second strip through a roller such that said particles of copper are sandwiched between said first strip and said second strip.
10. The bi-material strip of claim 5 , wherein the heating step includes induction heating.
11. The bi-material strip of claim 5 , wherein the process further includes feeding said strips through a quenching tank filled with a coolant after applying said second strip to said particles of copper.