Bodycote Heat Treatments UK :: Tungsten Carbide

HOT ISOSTATIC PRESSING (HIP) OFFERS THE POSSIBILITY OF ELIMINATING CLOSED POROSITY AND GIVES A HIGH SURFACE FINISH IN TUNGSTEN CARBIDE.

HIP thus improves material properties and may also improve the microstructural homogeneity.

The Bodycote HIP division offers a sub-contract HIP service as an integral part of the production route for such high quality parts.

Tungsten carbide is a metal matrix composite manufactured by mixing tungsten carbide (WC) particles with cobalt powder and subsequently sintering at between 1,350 degrees c and 1,500 degrees c.

During the heating phase of sintering the cobalt starts to dissolve the WC then in the isothermal sustain the cobalt is liquid with the maximum solution of WC in the liquid phase, this increases the densification rate of the part.

After sintering the porosity is typically less than 1%.

In the case of particularly low proportions of cobalt matrix or the use of nickel or other binder or when the tungsten carbide must be particularly free from porosity, the tungsten carbide should be HIPped.

Advantages

HIP improves the chemical and mechanical bonding of the WC phase in the metal matrix leading to improved integrity and enhanced mechanical properties such as transverse rupture strength, giving:

easier maintenance

longer maintenance intervals

fewer catastrophic breakdowns

The removal of residual porosity may greatly reduce the rate of rejection at final polish of such wear parts as extrusion dies and ball bearings.

Note that, even in the case where sinter HIPping is available, the much higher pressure of conventional HIP may offer significant technical advantage.

Applications:

Mechanical engineering

Petro-chemical industry

Glass industry

Graphic industry

Electrical industry

Forestry

Plastics industry

Automotive

Medical technology

Recycling

Textile industry

Mining