Managing casting porosity starts with identifying the affected function, defining acceptance and reviewing the casting and machining route. Inspection and leak testing answer different questions and must be specified for the actual component.
Define the consequence, not just the defect name
Internal discontinuities can matter differently for a structural bracket, a cosmetic housing or a pressure-containing component. Tell the supplier which surfaces are machined and which regions carry load or form a sealing boundary.
What should you ask your casting supplier?
- What internal-integrity requirements apply to this geometry?
- Will machining expose regions critical to sealing?
- What inspection method and sampling will be used?
- What leak rate, pressure and test conditions define acceptance?
- Should an alternative casting route be evaluated?
Separate capability from acceptance
CEX lists X-ray inspection and helium leak detection among its quality capabilities. Confirm which checks are included in your project. A general claim about low porosity is not a substitute for a written acceptance criterion.
Evaluate the manufacturing route early
Where internal integrity is central to the application, discuss squeeze casting during design review. The proposed process still needs validation for the actual alloy, geometry and operating requirements.
Turn a defect description into a requirement
| Concern | Information to provide | Verification discussion |
|---|---|---|
| Leak after machining | Leak location, machined section and test conditions | Agreed leak threshold and manufacturing stage |
| Internal discontinuity near a loaded feature | Critical region, drawing and service requirements | Inspection method, allowable indications and component validation |
| Visible opening on a finished surface | Surface location, appearance or functional consequence | Written visual standard and any further investigation |
Investigate before prescribing a remedy
Keep rejected samples identified by part and production lot. Record where the indication appears and whether it is observed before machining, after machining or during a functional test. Share representative sections or test records where available. A photograph alone is not enough to establish a root cause or approve a process adjustment.
Ask the supplier to review part geometry, tooling and process controls against the observed issue. A corrective action should address the identified cause and be verified on representative parts. Changing the casting route may be an option, but it is not a substitute for defining the acceptance requirement.
Write an actionable leak-test request
- Identify the pressure boundary, ports and surfaces that must be sealed in the fixture.
- Specify the test medium, pressure, allowable leak rate and units.
- State the stabilization or dwell requirements and part condition where applicable.
- Agree sample frequency or 100% testing, recording and disposition of failures.
Separate screening from proof of function
An internal inspection can help evaluate discontinuities; it does not automatically establish a leak rate or service life. Similarly, passing one leak test does not establish all mechanical requirements. Use the combination of checks needed for the component and record what each check demonstrates.
Further technical reading
These references support further study; they do not certify a CEX component. Use the applicable project specification for acceptance.