Things to know 
1. Hot Isostatical Pressure (post-compression procedure)
Previously sintered Cemented Carbide parts are held slightly below the sintering temperature and pressurised to around 1000 Bar by using an inert gas such as Argon, in a separate piece of equipment.

In an ideal situation the hard metal should be pressed into the pores under plastic viscous deformation. In practice this is seldom possible because only the binding metal (Co) will be softened. Therefore, due to the mutual supporting effects of the carbide crystals (2.5 – 3 µm), for the most part only Co will be pressed into the pores. Depending on the initial porosity unmixed binding metal up to 25 µm may develop.

The effect this external high pressure produces in the heterogeneous alloy system is an increase of internal energy especially between the WC / crystallite binding metal interface (compact/ductile – liquid). A reduction of this internal energy is made possible by reducing the surface energy of the ductile binding metal phases in that the Co links are being compressed and become larger globular particles at predisposed spots.
The increase in strength achieved by this porosity reduction is partly eliminated concentrations of the binding metal.
Differences between Hot Isostatical Pressing (HIP) and Sinter HIP Procedure
Differences between Hot Isostatical and Sinter HIP
1. Hot Isostatical Pressure
2. Sinter HIP Procedure Pressure

Plunger, Packing, Lubricant – a complex tribological system in LDPE hyper compressors
1. Introduction Pressure
2. Elementary structure of a plant for high-pressure polymerization of ethylene
3. The tribological system
4. Wear process in the tribological system
5. Practical knowledge from a carbide metal producer’s point of view
6. Other partners of the tribological system
7. Outlook
8. Summary
9. Reference

 2. Sinter HIP Procedure Pressure