What Factors Influence Tolerances in the Sintering Process? What Measures can be taken to Control Deformation caused by Sintering?

Date：2025-08-04   Views：1002

When parts enter the sintering process, they are brown parts. At this stage, the metal powder contains pores left behind by the binder, which is removed during debinding. Therefore, during sintering, the part dimensions shrink, thereby affecting the final dimensions.

Key factors affecting tolerances during sintering:

1. Temperature uniformity: Uneven temperature distribution within the furnace chamber causes inconsistent dimensional deviations in different parts of the component, disrupting geometric shapes.

2. Heating/cooling rate: When thermal stress exceeds the material's yield strength, it can cause instantaneous or delayed plastic deformation.

3. Holding time: Insufficient holding time results in uneven density, leading to uneven shrinkage and affecting performance.

4. Sintering atmosphere: Reactive layers can hinder densification or alter surface energy, leading to uneven shrinkage and deformation; uneven atmosphere flow exacerbates the effects of temperature non-uniformity.

5. Loading method: Significantly affects the uniformity of the temperature and atmosphere fields inside the furnace, and is an important factor causing tolerance differences within and between batches.

6. Material factors: Unevenness in metal powders and binders in the feedstock converts into dimensional unevenness during sintering.

7. Debinding residues: Uneven debinding damages the internal structure of parts, leading to local dimensional abnormalities and deformation.

Control measures:

1. Regularly conduct furnace temperature uniformity tests

2. Precisely control heating and cooling rates

3. Precisely control holding time and temperature

4. Select high-performance sintering furnaces

5. Precisely control sintering atmosphere

6. Reasonably arrange parts

7. Use specialized sintering fixtures

8. Improve feedstock uniformity

9. Monitor in real-time during sintering

10. Perform post-processing as needed

11. Complete debinding