Materials and contact shape studies for automobile connectors development

In automobile contacts, nominal contact resistance is required with low-cost materials such as copper alloys working in a wide range of currents (1 mu A to 50 A) and forces (1 N to several tens of newtons). The contact resistance of materials is studied in the initial state versus load, both in the inserting phase and during fretting motion. A specific test machine has been developed which allows statistical measurements under different initial conditions: base materials, contact shapes, and loads. The main results are the contact resistance law versus load: R/sub c/=k/sub c/F/sub c//sup -n/ and the insertion force law F/sub i/=k/sub i/F/sub c//sup m/ where the constants k/sub c/, k/sub i/, n, and m are correlated with material resistivity and contact shape characteristics.<
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