Internal porosities
Without direct consequence but which can become unblocking during machining operations. They are found inside the material and can be revealed by drilling or milling.
Impregnation
Why impregnation?
The majority of foundry parts are neither gas nor liquid tight. Impregnation is the only process that can definitively resolve waterproofing problems.
The origin of the leaks lies in the method of casting the metals. It is at this stage that the formation coves, sinkholes, porosities and other structural defects. These abnormalities are rarely detectable with the naked eye.
Increasingly complex parts, high quality requirements and cost constraints have made impregnation an essential response. It makes it possible to obtain a seal of up to 10⁻⁶ bars with helium and to withstand very high pressures (800 bars). In many cases, the impregnation is included in the range from the design stage.
Advantages of impregnation
- Upgrading leaky parts without scrapping them
- Securing hydraulic, pneumatic or cooling functions
- Long-term leak control, including in severe conditions
- No modification of dimensions or mechanical characteristics
- Parts ready for use after treatment, without retouching
10-6helium barsMaximum sealing
800barsPressure resistance
Validated process for automotive, aeronautics, gas, hydraulics and food.
Porosity categories
The external appearance of the porosity does not make it possible to determine the nature and importance of the defect. Impregnation is recommended after machining but before surface treatment to avoid penetration of stripping products.
Surface porosities
May cause appearance defects: bleeding, oxidation, degassing, stains. They affect the aesthetics and service life of the coatings.
Do you have parts to make waterproof?
Request a studyWhen to plan for impregnation?
The impregnation must be carried out after the machining operations and before surface treatment, because it is during this step that the porosities are revealed.
It can be integrated as a systematic operation on certain highly critical references or used as a targeted retrofit on batches with too high a leak rate. Maldaner can help you define the right compromise.
- In the project phase to secure a new part reference
- During material variations or foundry process changes
- As a backup solution to limit scraps on a series in difficulty
- As a step included in the range for parts with high sealing requirements
Go further
Discover our process and our services for sealing your parts.