# Hot-pressing dies

Graphite dies, punches and tools for hot pressing and densification at temperature.

Family: Thermal applications

## Description
Graphite dies, punches and tools for hot pressing. The process runs in a press/furnace; the documented application is the graphite tooling.

Ceramic tool inserts, armor plates, and sputtering targets are all classic "punch and die" hot pressing applications. The die must hold geometry under temperature and pressure, stay compatible with the atmosphere, and limit reaction with the workpiece.

## Grade selection

Selection is made on properties and heating mode.

- **Large cross-section** — a grade with relatively high electrical resistivity helps the die and punches reach temperature sooner.
- **High strength** — when pressure and geometry demand higher density and mechanical strength.
- **Spark plasma sintering (SPS)** — the die is part of the electrical circuit; grade resistivity is a selection criterion.
- **Resistance heating** — die components that carry the current are chosen for high electrical resistivity.

Provide die drawing, temperature, pressure, atmosphere and workpiece material so ESGRAF can recommend a grade and quote machined tooling.

## Processes
- Hot pressing
- Densification at temperature

## Challenges
- Tool deformation
- Reactivity with the workpiece
- Die service life

## Advantages
- High-temperature resistance
- Machining of complex geometries
- Good thermal conductivity

## Limitations
- Oxidation in air above roughly 400–500 °C
- Chemical compatibility with specific atmospheres
- Design must account for shrinkage and service life

- [Applications](https://esgraf.com/en/applications)
- [Alternate](https://esgraf.com/aplicaciones/prensado-caliente-dados)