Tungsten carbide or cemented carbide (WC) is well known for its hardness combined with strength and toughness. During the manufacturing process of cemented carbide the element Cobalt (Co) is usually chosen for the binder phase.

1. Manufacturing process of tungsten carbide blanks
Tungsten carbide or cemented carbide (WC) is well known for its hardness combined with
strength and toughness. During the manufacturing process of cemented carbide the element
Cobalt (Co) is usually chosen for the binder phase. The grain size of the WC can be made to
differ from 0.1µm to 10 µm over which fine control can be exerted. The grain size for a
particular application is an important variable that together with the cobalt content enables
the mechanical properties of the particular grade composition. There are different grades for
tungsten carbide blanks such as YG6X, YG8, YG10X, YL10.2 etc with diameters ranging
from D3-40 mm and length – 300,310, 330 mm and that can be cut in required lengths.
The manufacturing process of tungsten carbide blanks and tungsten carbide burrs
involves many processes that include mixing, sieving and granulating, automatic pressing,
isostatic
pressing,
presintering,
shaping,
vacuum
sintering,
hot
isostatic
pressing,
metallurgical quality control, grinding and final inspection. The manufacturing process
usually involves the working closely with the customers to produce the tungsten carbide
blanks with complex internal forms for use in harsh environments and performance critical
applications. The process of manufacturing tungsten carbide products inclusive of tungsten
carbide roll rings consists of the following below mentioned processes.
Weighing: The first step involves when the process engineering or the technical
department of the manufacturer is calculating the exact weights of all the materials to be
used in each grade. Finite calculations are required to control the ultimate carbon content so
that products with excess carbon or deficient in carbon are not produced. The finer the
powders (WC) more absorbed oxygen would be present and in vacuum sintering only the
carbon will remove the oxide present.
Ball Milling: The next step is the ball milling set at 80% of critical speed and the milling is
done in organic solvent such as acetone, heptanes, hexane and solvent naphtha. These
solvents are used to keep the balls clean at all times so that they impact the maximum
amount.

2. Screening: There powders are screened as liquid slurry through -200 or -325 mesh screens
to
remove
unmilled
manufacturers
particles,
contaminates
and
other
ball
chips.
Whereas
other
dry the powder first and then screen dry.
Drying: Drying includes using steam jacked tumbling vacuum dryers, bread type mixers
with an agitator, water cooled condensers etc.
Lubricant addition: Materials such as vacuum distilled paraffin, camphor; stearates etc are
used both as pressing aids and lubricants.
Pressing: All powders are spray dried or conventionally dried are ready to be pressed and
the pressing is either by isostatic, hydraulic or mechanical.
Presintering: Presintereing is required for items having intricate shapes, thin sections,
lower cobalt grades and titanium carbide containing grades that are more difficult to work
either in hydrogen atmosphere or in vacuum.
Preforming: Carbides that have not been pre-sintered are more fragile and require greater
care. Silicon carbide wheels “load up” readily and require constant dressing.
Sintering: Sintering methods used in tungsten carbide bars includes hydrogen, hydrogen
combination pre-sintering and final sintering, combination vacuum pre sintering & sintering,
vacuum sintering, combination vacuum sintering and hot Iso-Pressing.

3. Hot ISO pressing: After normal sintering is employed, the sintered parts are subjected to
a secondary consolidation that is called HIPing. The purpose is to take the binder phase
(cobalt) to near plastic conditions and exert pressure on every square inch of the blank to
move the carbide part sufficiently enough to fill any voids present.
After the above mentioned processes, the product goes through-in process and final
inspection before packaging to the consumer.