Why investment casting
Instrument and equipment parts in cobalt-chromium, stainless steel and titanium are cast to shape with fine surfaces that shorten polishing.
Components
- Instrument handles and jaws
- Device housings
- Equipment mechanisms; implants as a separate regulated field
Materials
Martensitic and PH stainless steels, 316L types, cobalt-chromium, titanium.
Frequently used alloys
| Grade | Type | Standard |
|---|---|---|
| Co-28Cr-6Mo (F75) | Cobalt-chromium-molybdenum casting alloy CoCrMo (Stellite® 21 type) | ASTM F75 |
| CF3M | Low-carbon Mo-bearing austenitic stainless steel, cast 316L type 316L type | ASTM A351/A351M, A743/A743M |
| CB7Cu-1 | Precipitation-hardening stainless steel, cast 17-4 PH type 17-4 PH® type | ASTM A747/A747M |
| Ti-6Al-4V (C-5) | Alpha-beta titanium alloy Ti-6Al-4V Ti-6Al-4V | ASTM B367 |
Typical requirements
Medical-device quality system and regulatory requirements govern the supply chain; suitability must be confirmed case by case.
- Sector quality system by project
- Surface integrity and cleanliness
- Lot traceability
Related engineering topics
Surface finish
Surface texture of investment castings: Ra and Rz, typical as-cast, blasted, ground and machined conditions, how to specify surface requirements and visual acceptance standards.
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.
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.