Electro-Spark Deposition (ESD) process
The process has been developed in the last 15 years and therefore it is less known. The ESD utilizes stored energy in condensators that is transferred to a consumable electrode such as: carbides (W, Ti, Cr etc) stainless steel, Inconel, Aluminium for a very short duration 1/1000 s. The temperature on the tip of the electrode is about 8.000 – 25.000 degrees C. The ionized material (electrode) is transferred to the substrate surface, producing an alloy with the substrate and a deposition on the alloyed interface electrode-substrate. The deposited layer has a metallurgical adherence on the impregnated or alloyed substrate with the electrode material. The impregnation is achieved especially when the electrode is made of carbides (WC, TiC). The ESD equipment is about 25-30 kg, is easy to use and allows in-situ applications (it is portable). During ESD deposition the substrate does not heat. The substrate features are controlled by the process parameters: spark energy, tension, spark duration, inductivity, frequency, temperature, number of passings, pressing force , speed. On the substrate there will be deposited a 0,03 – 0,17 mm thick layer and an alloyed or impregnated substrate about 0,03 mm thick.
ESD is used for:
– Resistance to any kind of wear
Leading edges of the blades are covered with WC or Stellite 6