Contact shoe as a medium to conduct electric current to the electrodes, is manufactured from copper with water canals in it for cooling. They are produced by casting or forging.
In casting approach, after preparing copper matrix related to the part design, copper casting is done precisely and then machined to attain exact dimensions according to design plans. Since casting quality (impurity and pores) is so important, it is a must to have radiographic tests for control the quality, weak points and pores beside hydro test which is done to diagnose leaks. Otherwise, identifying no leaks during hydro test may lead in future tiny leaks. Conductance of the casted contact shoes is about 85% of the standard electrical copper’s (IACS).
Forged contact shoes are produced after making special forging matrix or after forging copper block directly or half-prepared casted part with dimensions near final product. This type, in comparison to fully casted ones, benefits from more conductance (101% IACS) and more integrity with almost no pores and impurity, more reliability and of course more production expenses.
Araz Trans Co. with access to raw material of good quality, ability to build efficient punching dies and sophisticated machining equipments, produces both forged and casted copper contact shoes according to customer design plans or our own designing up on demands.
Below flow chart depicts various stages of copper contact shoe production process with casting, casting and then forging and fully forged approaches: