Tungsten Carbide and its Derivatives
Cross-section FTC
Welding layer
FTC
Overview
| DURMAT® | Chem. composition | Hardness |
|---|---|---|
FTCDURMAT® WSCFused Tungsten CarbideHardness: 2,360 HV0.1Chem. composition: WC-W2C Applications: Deep well drilling tools and rods, crusher jaws, mixers, concrete and stone saws, hot-pressed tools, screens & conveyors, extrusion housings, hard additives to diamond bits and saws Characteristics: For hardfacing of metallic surfaces exposed to extreme mechanical load and reinforcing the hardness of diamond tools |
WC-W2C | 2,360 HV0.1 |
SFTCDURMAT® SFTCSpherical Fused Tungsten CarbideHardness: 3,000 HV0.1Chem. composition: WC-W2C Applications: Deep well drilling tools and rods, crusher jaws, mixers, concrete and stone saws, hot-pressed tools, screens & conveyors, extrusion housings, hard additives to diamond bits and saws Characteristics: For hardfacing of metallic surfaces exposed to extreme mechanical load and reinforcing the hardness of diamond tools Increased apparent density combined with a better flowability |
WC-W2C | 3,000 HV0.1 |
| RF 13 | WC-Co 94/6 | 1,950-2,050 HV0.1 |
| MCTC | Monocrystalline Tungsten Carbide with 6.12% C-content | 1,600 HV0.1 |
WC IVDURMAT® WC IVHardness: 1,500 – 1,800 HV0.1Chem. composition: Crushed Tungsten Carbide with 6-10 % Co-content Applications: Mining, deep drilling–ason tool joints in the petroleum industry Characteristics: Concentrated wear protection for the area exposed to maximum wear Easy application of an extremely hard and abrasion resistant protective surface for highly stressed areas |
Crushed Tungsten Carbide with 6-10 % Co-content | 1,500 – 1,800 HV0.1 |
DURMAT® WC-Co alloys
Hardness
In WC-Co alloys of the same chemical composition, the hardness is mostly determined by the grain size of the carbide phase, which in turn depends on the primary grain size of the starting powder. When the grain size drops, the hardness increases considerably, meaning that a significantly high hardness level can be reached with the finest starting powders. The increase in hardness is always accompanied by the rise in coercive field strength.High temperature hardness
With increased grain fineness, these alloys also feature improved hardness properties at high temperatures, so that strength benefits emerge in hightemperature use particularly for wear protection layers made from them. The nano-scale WC raises the strength level a stage higher.Toughness
A smaller grain size in the carbide phase with the same Co content results in a decrease in the difference between WC grains and hence to a reduction in particle movement.Compressive strength
The high compressive strength of these carbide alloys is one of the most important properties in these materials, as it is significant in practically all technical applications. After diamond, hardmetal (cemented tungsten carbide) is the most pressure resistant material. This property is also of predominant significance in wear protection. The increase in the microstructure leads to a significant rise and as a result these nano tungsten carbides have the highest compressive strength.
WC-Co-grain
WC-Co-pellets in Ni-matrix
WC-Co
1. Abrasive wear
The greater hardness of the nano-scale hardfacing alloy associated with the decreasing WC grain size reduces wear from abrasion considerably. The harder “hardmetal” counters abrasion with a greater resistance.Wear progresses significantly slower, as the binding metal layer between the fine grain hardfacing crystallites is exceptionally thin, making it harder to wash out. Due to this structural attribute, only very small hardfacing particles are torn out of the structural bond. The spherical shape represents a further form of protection, which is further stabilized by the small grain size; small particles have to expend a great deal more energy to divide and become smaller than coarse ones.
2. Corrosive wear
A characteristic, higher wear resistance also occurs with regard to corrosive wear. As a result of the nano-structure and in particular the significantly reduced intermediate binding metal layer, the corrosive media can only reach the cobalt with difficulty, leading to considerable delays in wear. In turn, only the smallest hardfacing particles escape, corrosion is slowed down considerably.As in most applications, abrasive and corrosive wear are barely distinguishable, due to the improvement in properties that can be achieved.
DURMAT® FTC
General information
Fused Tungsten Carbide (FTC) is an extremely hard, wear resistant material. Its abrasion resistance is superior in terms of wear resistance to all other commercially available materials except diamond. It is far superior to any of the chromium carbide products presently in use and will always deliver very positive test results by comparison. This material forms the basis of all DURUM’s abrasion-resisting products.The properties of the FTC are very much dependent on its structure. FTC which demonstrates at least an 80 % “feather” structure has a macro-hardness of approximately 2,000 HV30. The micro-hardness of this material has been measured at 2,300 - 2,500 HV0.1.
FTC has a carbon content of 3.8 - 4.1 %. This corresponds to a ratio of 78 - 80 % W2C and 20 - 22 % WC. Careful attention must be paid during the processing and application of products containing FTC, that the temperature does not exceed 1,800 °C. Higher temperatures would cause an alteration in the structure resulting in a loss of hardness. If this excessive overheating occurs during the welding procedure, an unproportionately high amount of FTC will be dissolved in the iron matrix, which would also result in a reduction of the material’s superior ability to resist wear.
DURMAT® SFTC
DURMAT® Spherical Fused Tungsten Carbide (SFTC) is the most wear resistant Fused Tungsten Carbide we can offer.
Using powder metallurgical processes, it is possible to produce parts of nearly any shape, which can contain hard materials or diamonds together with a metal binder and SFTC, reinforcing the hardness of diamond tools. Excellent for deep well drilling tools and rods, crusher jaws, mixers, concrete & stone saws, hot-pressed tools, screens & conveyors, extrusion housings and hard additives to diamond bits and saws.
General information
These spherical fused tungsten carbide particles show a fine non-acicular structure with a higher hardness than conventional FTC (> 3,000 HV0.1). The increased apparent density combined with a better flowability enables an increase of hard particles in wear resistant coatings and components produced by infiltration.Using powder metallurgical processes, it is possible to produce parts of nearly any shape, which can contain hard materials or diamonds together with a metal binder and SFTC, reinforcing the hardness of diamond tools. Excellent for deep well drilling tools and rods, crusher jaws, mixers, concrete & stone saws, hot-pressed tools, screens & conveyors, extrusion housings and hard additives to diamond bits and saws.