Vacuum impregnation allows to achieve 100% of hermiticity of the metal products under overpressure from 2 to 200 kg/cm2. Moreover, such treatment may significantly improve the quality of the metal surface prior to application of finishing decorative coatings.
Impregnation by sealants according to vacuum technology can subject not only to metal parts, but also to modern electronic components – relay actuator, connectors, integrated circuits. Moreover, performance reliability of their work even in the most difficult conditions is improved by several times.
Used sealants are resistant to the majority of metals, alloys and other structural materials. This means that almost all can be subjected to impregnation: bronze, aluminum, iron, fiberglass, ceramics, etc.
Process of the impregnation
The duration of metal vacuum impregnation process is only 25-30 minutes at a polymerization temperature of 90 °C. Impregnation process takes no longer than 15 minutes. Operating temperature can range from -90 °C to +200 °C. Pressure level is limited to the magnitude which can be hold by the material of workpieces.
Impregnation is performed after the completion of all machining operations. Parts made according to powder metallurgical practice are machined after the sintering but before the finish operations.
Castings are subjected to degrease cleansing treatment and drying before the impregnation. Thereafter, parts are ready for machining and placed in a special container in a vacuum chamber. The chamber is then filled with impregnating composition, in which the parts are left for some time. After it’s created the excessive pressure in the chamber and sealant is drained. To remove the excess of impregnation from the surface of parts is carried out the centrifuge process. This procedure allows to clear small structural holes and thread from the impregnating composition and to minimize its consumption: up to 3g per kg of cast aluminum.
By applying the impregnation is achieved complete gas- hydrotightness of castingproducts, is prevented pore corrosion, is increased the endurance strength by removing of stress concentrator for 15-20%. The yield of hermetically sealed parts is 98-100%. Details treated according to the technology, remain hermetically sealed, are capable of holding any liquids and gases, including aggressive and under high pressure.
At that, the technology of vacuum impregnation is environmentally clean, effluent water and waste are not toxic and are subjected to biological decomposition.