Stress reduction during the densification of metal powders

Conclusions

• 1. In investigations of the densification process of metal powders, it is convenient to introduce the concept of stress reduction — a magnitude determined as the differerence between the athermal strengthening effect and the pressing stress.

• 2. The degree of stress reduction is related to the temperature and degree of densification of powders by a power function, and increases as these two parameters are increased.

• 3. The relationship between stress reduction and densification rate has a logarithmic character; with rise in the rate, the extent of stress reduction falls.

• 4. The possibility is shown of separating the strengthening from the strength-loss effect in the overall pressing pressure.

• 5. It has been established that, with rise in the degree of powder densification, the strengthening effect increases, while the fraction of the strength loss falls.