Optimize density & grain structure.
Fabricate Unique Materials
Hot Pressing is useful to fabricate unique materials, especially hard and brittle ceramic and metal materials from powders. In addition, these powders are pressed into a near-finished shape of material that would otherwise be very expensive to purchase as raw material and then machined into shape. Examples e.g.:
- Diamond-metal composite cutting tools
- Advanced, technical, as well as machine-able ceramics
- Boron Carbide (B4C)
- Silicon Carbide
- Tungsten Carbide
Hot Pressing Process
A brief overview of the hot pressing process:
- The metal or ceramic powder is placed into a stationary die within the vacuum furnace.
- The furnace is heated and ran at a specific temperature profile, while simultaneously pressing vertically down upon the powder with a hydraulic ram.
- While the force is applied vertically, there is also radial pressure created against the die wall, and these pressures together with the heat result in effective particle joining.
- The densification begins with particle rearrangement and plastic flow at the particle contacts, and progresses into grain boundary diffusion, creating the finished material.
- Finished parts do usually require some diamond grinding to achieve the final shape tolerances.
Hot Pressing Equipment Capabilities
VPE is able to use any of its diffusion bonding furnaces as hot pressing furnaces. As a result, this allows for small, medium, and large-sized batches.
- A controlled atmosphere under vacuum to avoid contamination
- Interface assisted
- Long cycle and minimum strain
- Partial pressure control for up to three gases
- High volume production
- Quick cooling argon-to-water heat exchangers for high-production-rate processing
The World’s Largest Vacuum Hot Press
VPE also owns the world’s largest vacuum hot press furnace, giving customers advantages with large batch sizes!
- Usable chamber area of 60 in. x 120 in. x 120 in.
- Temperatures in excess of 1900° Celsius in vacuum and partial pressure atmospheres.
- Two independent 1200 ton rams allow for loads to 4.8 million lbs.
- Assembly weights in excess of 60,000 lbs.
- Ten high accuracy load cells allow precision force and precision control on the production elements.