Grain tungsten carbides

Carburization By Fusion. This method is used for the preparation of tungsten carbide for the mineral industry, ie, for coarse-grained powder or castings for welding (qv) onto oil drills and wear-resistant parts. 

Special carbide tools also will often contain various percentages of titanium, tantalum, niobium icolumbium). and hafnium carbides, along witii die tungsten carbide. Chromium and vanadium carbides are also added to produce special, fine-grain-size grades of cemented tungsten carbide-cobalt materials. See Fig. 1. 

Figure 2.4 Representative microstructures of steel-cutting grades of cemented tungsten carbide (a) 94%WC-6%Co alloy, submicron grain size, (b) 94%WC-6%Co alloy, medium grain size, (c) 86%WC-8% (Ti, Ta, Nb)C-6%Co alloy, medium grain size. The gray angular particles are WC, and the dark gray, rounded particles are solid-solution carbides. The white areas are cobalt binder. (Ref. 14).

Cobalt Content and Tungsten Carbide Grain Size... 

In most cases, there are used short solid tungsten carbide drills. Tungsten carbide with ultraflne grain size is the most suitable cutting material. For larger diameters (>12 mm), there are applied boring tools with indexable tips, mostly coated with titanium nitride (TiN),... 

Micro-pencil Grinding Tools Micro-pencil grinding tools (Fig. 2) are applied for generating microstructures. These tools are manufactured in different ways, for example, tungsten carbide blanks with electroplated CBN or diamond grains. Diameters down to 5 pm can be realized (Aurich et al. 2009). 

WEDG is a process similar to electrodischarge machining but with support of the wire to reduce vibration and increase the accuracy. It also allows to remove minimal amounts of workpiece due to extremely short pulses. Combined with cemented tungsten carbide as tool material with a grain size of 0.6 pm, USM mills can be manufactured (Egashira et al. 2011). 

Cutting tools made from nanomaterials such as tungsten carbide, tantalum carbide, and titanium carbide suffer less wear, display more erosion resistance, and last longer than their conventional (large-grained) counterparts. They are used to drill holes in... 

---