Due to its high melting point tungsten carbide (WC) can only be produced through sintering when needed for technically sophisticated applications. For this purpose, the powder consisting of the tungsten carbide, The cobalt binder (Co) and sometimes additional alloys, is mixed, milled and spray-dried. This process results in a spray-dried granulate which can easily be used for production, since its chemical and physical properties have already been adapted to the final carbide specification (e.g. WC grain size).
Manufacture and machining of blanks
By applying pressure the carbide powder is converted into a blank. The material will receive its near net shape through the application of traditional machining methods (sawing, drilling, milling, turning), so that extended machining of the sintered carbide blank is no longer necessary. The density of the blank is approx. 50% of the sintered carbide‘s density which leads to an approx. 20% shrinkage in length.
The sintering process converts the blank into a homogeneous piece of carbide with a high degree of hardness. When sintering hard metal (usually at a temperature of approx. 1400°C), this process is called liquid phase sintering. In this case, the binder (e.g. cobalt) melts and wets the WC hard material particles. After sintering, the density of the carbide is almost, or even precisely, the same as the theoretical density. Any residual porosity which occurs after the sintering procedure may be removed through an ensuing HIP process.
CNC external and internal cylindrical grinding Face and parallel lapping CNC surface and profile grinding CNC 5-zxes-grinding Precision center-less grinding
Coatings / surface treatment
Our coating competence covers classic hard material coatings and functional tailor-made coatings for specific customer applications. For the production of coatings we apply CVD, PVD and galvanic processes. Special surface treatments are mainly applied to improve brazing properties.
For several applications it does not make sense to manufacture the entire component in hard metal. The use of hard metal is limited to the area in which wear occurs. Materials with suitable wear resistance are used for the carrier tool; they are easier to machine than carbide. For the combination of carbide with other materials, numerous tried and tested technologies are applied. Examples: brazing, gluing, clamping, connections with screws and shrinking.
Carbide treatment by means of spark erosion meets the highest technological standards. Wire erosion and cavity sinking by EDM additionally guarantee high precision. Long-standing experience combined with carbide grades that are specially adapted for erosion guarantee optimum machining results.
The control of finished components is part of our certified quality management system. This control is carried out by qualified staff, mainly on computer-controlled measuring machines. Control records are archived for 10 years. Upon request the customer can view the quality management records which are relevant for him.