What is the immersion process?

In a microporous (slit) infiltration sealing process, the sealing medium (usually low-viscosity liquid) through natural infiltration (i.e., microporous self-priming) vacuum and pressure and other methods to infiltrate into the microporous (slit), the gap will be filled and then through natural (room temperature) cooling or heating methods to seal the gap in the sealing medium fixed, to achieve the role of sealing the gap.

Why immersion

The appearance of pores in the material is a common phenomenon, especially in die-casting and powder metallurgy manufacturing processes, due to the residue of pores, crystal shrinkage, and other reasons inevitably forming.

A large number of microporous sand holes, cracks, etc., microporous leakage will bring hidden dangers to the use of machinery and equipment, even for non-pressure requirements of the user, may be due to electroplating, painting, and surface treatment.

The plating solution, acid, etc., into the internal casting corrosion, shortening the service life of the parts due to the existence of micro-porous surface painting, plating, etc., to form bubbles or unevenness.

The product scrapping is almost zero through immersion, greatly saving costs and fully using limited resources to produce a perfect product.

Impregnation process

The die-casting dipping process is divided into three stages: pre-treatment, dipping, and post-treatment.


The pre-treatment process includes cleaning and drying processes.

2.Impregnation treatment

The impregnation process includes workpiece vacuuming, negative pressure inhalation of the impregnating agent, pressurized out of the impregnating agent, atmospheric pressure out of the workpiece, and other processes.


The post-treatment process includes rinsing, heat curing, test pressure, and other processes.

The role and purpose of infiltration

A.Giving pressure resistance and sealing function

Filling the micro-pores of the product with the dipping solution plays a sealing role.

B.Giving corrosion resistance function

Plugging the micro-pores that are connected or not connected can prevent internal corrosion.

C.Pre-treatment of synthetic treatment

Filling inside the open seam can prevent discoloration, corrosion, and swelling.

D.Improve cutting and processing performance.

Filled with the metal inside the infiltration fluid can play the role of lubricant to extend the tool life and reduce machining costs.

E.Improve physical strength.

Immersion fluid filled and plugged micro-hole internal gap reduction, physical strength is improved, can make the product design thin-walled

F. improve insulation

Plugging the internal cavity can improve the protective effect of the electric sun value

Application scope of immersion technology

Immersion of castings

The main effect of casting infiltration is to seal against leakage so that it can be used in hydraulic and gas systems. For example, automobile and tractor transmission bodies, fuel pumps, hydraulic valves, carburetors, cylinders, compressors and hydraulic components, airtight aircraft instruments and their electronic instrument shields, pneumatic parts, and a variety of pneumatic instruments, etc…

Casting infiltration can also prevent internal corrosion and improve yield. As we all know, the internal corrosion of castings is often from the microporous; when the microporous is filled with an infiltrating agent to be cured, it can prevent the infiltration of corrosive liquids, to play a role in anti-corrosion.

In addition, castings can also be prepared for electroplating, painting, and other surface treatment, as the immersion agent fills the voids in the castings to avoid the absorption of these voids plating solution after plating caused by bubbles and non-glossy surface.

Dipping can be used as castings; die castings often exist as a remedy for defects such as loosening and microporosity, but also to promote the casting product design of thin-walled, lighter, saving the consumption of materials.

Powder metallurgy infiltration of parts

 Powder metallurgical materials have excellent performance, so cars, tractors with bushings, valve guides, gears, cams, shingles, clutch friction plates, electric heating elements, heat exchangers, cutting tools, molds, and some corrosion-resistant, high-temperature oxidation and high-temperature parts are now widely used in the manufacture of powder metallurgical materials.

Powder metallurgy parts are made of metal powder (or a mixture of metal and non-metal powder) as raw material, pressed into shape, and then sintered to make various workpieces. Powder metallurgy parts are characterized by many internal pore networks (about 15% of the entire volume of the workpiece), including small air spaces between the powder metal particles; even if it is a high-density powder metallurgy parts, such pores still exist. Therefore, powder metallurgical parts cannot be kept in liquid. Impregnation treatment of powder metallurgy parts can fill its internal pores by the impregnating agent and achieve permanent sealing so that it can be used in hydraulic systems; for example, it can be used to manufacture precision oil pump parts, compressor housing, etc.

 In addition, powder metallurgy parts in electroplating or other surface coating treatment before the immersion treatment, electroplating solution, and cleaning agent will not be absorbed into the pores, and you can get a clean surface and corrosion-resistant workpiece.

It must be noted that the powder metallurgy parts should be immediately after the sintering immersion treatment because then the pores are clean and easy to be filled by the immersion agent. After the powder immersion, metallurgy parts can also improve their cutting performance (micro-porous by filling the tool will become continuous cutting from intermittent cutting) to facilitate the control of the process.

Impregnation of electronic devices

The transformer, capacitor, motor, and other electrical parts of the infiltration can increase their dielectric properties and insulation properties. For example, the stator of the motor and the assembly of the shell after the assembly, the infiltration to form a single whole, after the infiltration of the micro-hole can be sealed, and increase the strength and heat dissipation effect, to solve the motor due to vibration and reduced insulation performance. In contrast, the infiltration of the motor in a humid environment can still maintain good insulation performance and improve the reliability and service life of the motor.

Immersion of non-metallic parts

Non-metallic materials, such as wood (sleepers, poles, etc.), ceramics, and fiber plastic synthetic materials, the use of infiltration treatment can extend the service life and improve their water resistance. For example, the cooling system parts of large computers are generally made of FRP-reinforced plastic, which can be effectively sealed by infiltration, thus preventing leakage of liquid through the micro-fine reinforced fibers as a channel.

From the above, it can be seen that infiltration technology has a wide range of applications in the sealing of electromechanical products and porous material parts.

LK 2000T die casting machine

Advantages of aluminum die-casting infiltration

Cost saving

1.the mold used for aluminum alloy die-casting parts infiltration can be used for life with almost no loss, reducing or eliminating the mold cost. 2.

2.Aluminum alloy die-casting parts impregnation eliminates the traditional core molding process, saving labor and reducing manufacturing costs.

3.aluminum die casting impregnation has evolved from a foundry industry with a large number of male workers to a large number of female workers; labor is greatly reduced in all aspects and the cost of workers from the wages.

4.aluminum die-casting impregnating sand can be recycled with a loss of 2%-5%.

Improve efficiency and production

1.aluminum dies casting impregnation with foam model for mechanical foam. While ensuring the quality of the model, the production speed is also quite fast.

2. the aluminum alloy die-casting infiltration process simplifies the traditional process’s tedious steps, such as the core shape, not only laborious and inefficient.

3.aluminum die-casting parts are impregnated in a box and multiple injections and can cast multiple boxes at the same time until the metal solution is used up.

Improve product quality

1.Aluminum die-casting parts dipping will eliminate the defects or scrap caused by molding cores because no molding cores are needed.

2.No need to beat the box, avoiding the defects or scraps caused by flash burrs in the box buckle box and improving the product precision.

3.After the furnace body is discharged, most paint can be peeled off naturally without adding flash burrs. Therefore, the cleaning time can be reduced by more than 50%, and the cleaning cost can also be reduced.

4.Because the aluminum alloy die-casting parts are impregnated with dry sand solid type negative pressure casting, eliminating or reducing the defects such as pores and sand holes in the casting.

5.Since the aluminum alloy die-casting parts are impregnated by the foam molding model evaporation, the metal solution replaces the model, and the original shape is as close as possible to the precision casting in terms of surface finish and dimensional accuracy.

If you would like to know more, you can contact us and we will be happy to provide you with what you want to know


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What is the immersion process?

In a microporous (slit) infiltration sealing process, the sealing medium (usually low-viscosity liquid) through natural infiltration (i.e., microporous self-priming) vacuum and pressure and other methods

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From V1Diecast, I’m a the marketing manager. I am familar with die casting parts and die casting technologies, including vacuum die casting, aluminium die casting, and related surface finishings. Ask for a quote for your ongoing or upcoming projects now!

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