Heat treatment is frequently used to improve adhesion or to modify properties in order to satisfy the needs of a particular application. As a result of heat treatment, hardness, corrosion resistance, wear resistance, ductility and stress, fatigue properties, magnetic properties, and other qualities of the deposit can be affected. The chart on the right indicates changes of EN hardness as a result of heat treatment which is normally performed at temperatures of 200 degrees to 750 degrees F for 30 minutes to several hours. Maximum hardness is produced by heating to 750 degrees F followed by a slow cooling to 390 degrees F or lower. This hardness can be as high as 65RC.
ENP currently has two ovens for pre-plate and post-plate heat treatments in batches of up to 250 cubic feet. Each oven is calibrated to national standards and has a dedicated computerized control and chart recorder.
Brush plating is an electroplating process performed with a handheld or portable plating tool instead of a tank solution. This process is also referred to as contact plating, selective plating or swab plating. The procedure, in its simplest form, is similar to a painting operation. The operator first soaks the plating tool in plating solution. Afterwards the plating material is deposited by brushing the plating tool against the base material. The plating solution is then delivered to the work area with a porous, absorbent cover wrapped over the anode of the plating tool. A portable power pack provides a source of direct current for the process. This power pack has two leads: one connected to the plating tool and the other to the part being plated. A direct current circuit is completed when the plating tool, which is always kept in motion, is placed on the part and when electroplating occurs.
Operations that prepare the base material for plating are similar to the plating operation itself. Those performed prior to plating ensure an adherent deposit.