An 8-step process: (1) Powder sourcing — find a qualified powder supplier with the right PSD and purity. (2) Feedstock development — determine optimal powder loading through CPVC testing. (3) Molding trials — verify the feedstock molds without defects. (4) Debinding optimization — establish debinding parameters. (5) Sintering development — determine temperature, atmosphere, and time. (6) Mechanical testing — verify UTS, yield, elongation, hardness meet targets. (7) Dimensional validation — confirm shrinkage is predictable and repeatable. (8) Documentation — create material specification, process specifications, and control plan.
Qualification timeline:
| Phase | Duration | Activities | Deliverables |
|---|---|---|---|
| Powder sourcing | 2-4 weeks | Identify suppliers, obtain samples, test PSD + chemistry | Qualified powder source(s) |
| Feedstock development | 2-3 weeks | CPVC testing, compounding trials, MFI verification | Approved feedstock formulation |
| Molding trials | 1-2 weeks | Mold test bars, verify flow and green strength | Molding parameters |
| Debinding + sintering | 2-3 weeks | Optimize cycle, measure density and shrinkage | Sintering parameters |
| Mechanical testing | 1-2 weeks | Tensile, hardness, metallography | Property data sheet |
| Documentation | 1-2 weeks | Spec sheets, control limits, QC procedures | Complete qualification package |
| Total | 10-16 weeks | — | — |
| Test | Standard | Sample Size | Acceptance Criteria |
|---|---|---|---|
| Tensile (UTS, YS, El) | ASTM E8 / MPIF 10 | 5 samples per sintering condition | ≥ MPIF 35 minimums |
| Hardness | ASTM E18 or E10 | 5 readings per condition | Per material spec |
| Density (Archimedes) | ASTM B311 | 3 samples per batch | ≥ 95% of theoretical |
| Metallography | ASTM E3, E407 | 1 sample per condition | No excessive porosity, correct phase structure |
| Dimensional shrinkage | CMM, 10+ features | 10 samples | Within ±0.5% mean range |
| Surface finish Ra | ISO 4287 | 3 measurements | Per target spec |
| Salt spray (if applicable) | ASTM B117 | 3 samples | Per target hours minimum |