Why investment casting
Complex, weight-optimised parts in high-strength and heat-resistant alloys are cast close to final shape, which removes machining from alloys that are slow and costly to cut.
Components
- Structural brackets
- Housings
- Fuel and air system parts
- Turbine hardware
Materials
Precipitation-hardening stainless steels, nickel superalloys, aluminium, titanium.
Frequently used alloys
| Grade | Type | Standard |
|---|---|---|
| CB7Cu-1 | Precipitation-hardening stainless steel, cast 17-4 PH type 17-4 PH® type | ASTM A747/A747M |
| Alloy 718 | Precipitation-hardening Ni-Cr-Fe-Nb superalloy Inconel® 718 type | SAE AMS 5383 (investment castings) |
| A356.0 | Al-Si7-Mg heat-treatable casting alloy AlSi7Mg0.3 | ASTM B618/B618M (investment castings); AA A356.0 |
| Ti-6Al-4V (C-5) | Alpha-beta titanium alloy Ti-6Al-4V Ti-6Al-4V | ASTM B367 |
Typical requirements
Sector-specific quality system approvals, special-process control and full traceability are mandatory and must be confirmed per project.
- Full heat and batch traceability
- NDT to defined acceptance classes
- First-article inspection report
Related engineering topics
Non-destructive testing
NDT methods for investment castings: liquid penetrant, magnetic particle, radiographic and ultrasonic testing, computed tomography, leak testing, personnel qualification and acceptance levels.
Documentation
Documentation for investment castings: EN 10204 inspection documents 2.1, 2.2, 3.1 and 3.2, material certificates, dimensional and NDT reports, heat-treatment records and traceability.
Tolerances
Tolerancing of investment castings: ISO 8062-3 casting tolerance grades, VDG P 690, geometrical tolerances to ISO 1101, datum systems, machining allowance, shrinkage and distortion.