Thermogravimetric Analysis (TGA) measures the weight change of a small sample of MIM feedstock as it is heated. The resulting weight-loss curve shows exactly how much binder is present and at what temperatures it decomposes.
What a MIM TGA curve tells you:| Information | How TGA Shows It | What It Means |
|---|---|---|
| Binder content (%) | Total weight loss from 200-550°C | Should match the target binder content within ±0.5 wt% |
| Binder decomposition temperature(s) | Weight loss steps at specific temperatures | Confirms the correct binder system is being used |
| Residual carbon after burnout | Weight remaining after heating to 600°C in air | Indicates potential carbon contamination risk |
| Inorganic content (metal powder) | Weight remaining at 800°C | Matches the target powder loading |
| Temperature Range | Weight Loss | What Is Happening |
|---|---|---|
| 25-200°C | < 0.5% | Moisture evaporation, low-volatile components |
| 200-400°C | 4-6% | POM depolymerization — primary binder decomposition |
| 400-500°C | 1-2% | Secondary binder components (PE, PP, stearic acid) |
| 500-800°C | < 0.5% | Any residual carbon burn-off |
| > 800°C | Balance remaining | Metal powder — should be 92-96 wt% depending on formulation |
- Incoming feedstock verification: Run TGA on every batch — the curve should overlap the reference curve from the qualified batch
- Debinding optimization: TGA of brown parts confirms how much binder remains after debinding
- Root cause investigation: If parts show black lines or carbon contamination, TGA of the feedstock versus a reference batch can reveal if the binder content has drifted
TGA (Thermogravimetric Analysis) is a test that measures how much weight MIM feedstock loses as it is heated. It produces a weight-loss curve that confirms the binder content (should be within ±0.5 wt% of target), the binder decomposition temperature (confirms correct binder chemistry), and the metal powder content. It is a standard QC tool for incoming feedstock verification.