The manufacturing process begins with the composition of a specific tungsten carbide powder mixture - tailored for the application.

The tungsten carbide powder is compacted into a form.

In a high-temperature sintering furnace, the tungsten carbide structure of the blank is shaped at precise temperatures for strictly defined periods. During this heat treatment, the tungsten carbide blank undergoes shrinkage of some 50% in volume.

The sintered Cemented Carbide component gains its final finish by additional grinding, lapping and/or polishing processes.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

The Cemented Carbides are a range of composite materials, which consist of hard carbide particles bonded together by a metallic binder.

The proportion of carbide phase is generally between 70-97% of the total weight of the composite and its grain size averages between 0.4 and 10 μm.

Tungsten carbide (WC), the hard phase, together with cobalt (Co), the binder phase, forms the basic Cemented Carbide structure from which other types of Cemented Carbide have been developed. In addition to the straight tungsten carbide – cobalt compositions – Cemented Carbide may contain varying proportions of titanium carbide (TiC), tantalum carbide (TaC) and niobium carbide (NbC). These carbides are mutually soluble and can also dissolve a high proportion of tungsten carbide. Also, Cemented Carbides are produced which have the cobalt binder phase alloyed with, or completely replaced by, other metals such as iron (Fe), chromium (Cr), nickel (Ni), molybdenum (Mo), or alloys of these elements.

There are three individual phases which make up Cemented Carbide. In metallurgical terms, the tungsten carbide phase (WC) is referred to as the a-phase (alpha), the binder phase (i.e. Co, Ni etc.) as the b-phase (beta), and any other single or combination of carbide phases (TiC, Ta/NbC etc) as the g-phase (gamma). Other than for metal cutting applications, there is no internationally accepted classification of Cemented Carbides.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

A unique material
Cemented Carbide is one of the most successful composite engineering materials ever produced. Cemented Carbide's unique combination of strength, hardness and toughness satisfies the most demanding applications.

A key feature of the Cemented Carbide is the potential to vary its composition so that the resulting physical and chemical properties ensure maximum resistance to wear, deformation, fracture, corrosion, and oxidation. In addition, the wide variety of shapes and sizes that can be produced using modern powder metallurgical processing offers tremendous scope to design cost-effective solutions to many of the problems of component wear and failure encountered in both the engineering and domestic environment.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

Cyclic Heat Treatment

Cyclic heat treatment of the alloy properties also have a certain impact, mainly reflected in the W - Ni - alloy cyclic heat treatment can alter the uniform distribution of binding phase is conducive to penetrate phase sintering of tungsten - tungsten grain boundaries, reducing tungsten - tungsten distance. NohJoon-Wong, who studied tungsten -5.6 93 -1.4 iron-nickel cyclic heat treatment process, the sintered tungsten alloy in a nitrogen atmosphere at 1150 ℃ incubated for 1h, then water quenching, this process is repeated several times, the results show that with the increase in the number of cycles to infiltrate tungsten - tungsten grain boundary phase volume increased bonding, bonding phase can be more fully penetrate to WW grain boundaries.

Circulation of heat treatment on the tensile mechanical properties of the alloy of tungsten grain size related. When the tungsten grains from the 25μm to 100μm, although the use of cyclic heat treatment, the tensile strength and elongation still down, respectively, and 25% down from 920MPa to 740MPa and 11%, after a heat cycle, the impact absorbed energy from 50J dropped to 22. SJ. When W is the grain size is reduced to 25-35μm, the cycle of heat treatment on the absorbed energy increased significantly affected. Alloys from 57J impact energy up to 170J, impact specimen fracture morphology changed greatly from tungsten - tungsten interfacial fracture to the dimple-like ductile fracture binding phase change.

Deformation and Then Crystallized

Cold working such as extrusion, rolling, forging, etc., may increase the tensile strength, but the alloy has decreased ductility. Alloy microstructure by cold deformation of fibrous texture, this texture with penetrators axial orientation have a greater impact on the performance of the alloy, thus affecting its penetration performance. Goren et al cold deformation after crystallization was studied tungsten -7% 90% -3% Ni alloy after swaging (diameter shrinkage of 82%) and annealed at 1480 ℃ 40s obtained crystals uniformly round lOlμm tablets. And the greater the deformation, the shorter the annealing time. In the annealing process, the larger tungsten grains (30-50μm) first forming sub-grain boundaries, some of the molten adhesive through the sub-selective phase boundary, the last elongated tungsten grains are divided into smaller round tungsten grains, thereby significantly improving the microstructure of the alloy.




Tungsten Alloy Manufacturer & Supplier: Chinatungsten Online - http://www.tungsten-alloy.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

 

Strain hardening is the use of a metal ( or alloy ) hardening principle , in the deformation of the material deformation under pressure to change and improve the organization of defects in tungsten alloy quantity, distribution and organizational structure of the alloy , thereby enhancing the strength of the material of an enhanced technique . In the strain hardening process, the deformation properties of tungsten alloy has a very significant impact. With the increase of the deformation , the tensile strength and hardness increase and decrease ductility . The beginning of deformation, strengthening the role of apparent when deformation of > 15%, the strengthening effect gradually weakened . Strength with the increase of the deformation , when the hardness is gradually increased to a certain value, it no longer increases with the increase of the deformation has changed significantly. The tungsten content of 95 % tungsten alloy , when the deformation amount of 15 %, the hardness reaches the maximum. The universal deformation strengthening process, the amount of deformation is 15 % and the maximum deformation of not more than 25% tungsten alloy or microcracks internally , cracking and lead to destruction . Aging the alloy after deformation processing , the tensile strength can be further improved . Strain age hardening temperature is usually in the 500-600 ℃. In this temperature range , and annealing interface has strengthen tungsten particles , so that the strength of the compression deformation of 32% of 90W-Ni-Fe alloy , aging in 600C th, tensile strength of 1530MPa or more can be achieved . Annealing above 600 ℃ , with the annealing temperature, the strength and hardness decreased , elongation recovery , when the annealing temperature reaches above 1200 ℃ , the occurrence of recrystallization , intensity and sintering heat treatment extends to its original state levels.

In order to significantly improve the mechanical properties of tungsten alloys , in recent years , the development of large deformation advanced tungsten alloy strain hardening technology . Large deformation strength than ordinary forging state to raise more than 300MPa . Large deformation and deformation generally through several intermediate annealing cycle process and implementation, the deformation and deformation cycles have a great relationship with the technology in the forging process of cyclic deformation on the piece several times and intermediate annealing treatment can achieve a large deformation strengthening . The purpose is to eliminate intermediate annealing deformation stress generated during processing , reduce the processing hardening , annealing temperature range is generally at 500-1000 ℃. In addition , in recent years the development of some of the more advanced large deformation hardening process , such as static extrusion, hot extrusion , hot-rolled or hot extruded ( hot ) with forged composite deformation technique , it can achieve a very large amount of deformation the tungsten alloy showed fibrous microstructure of the alloy strengthening effect is very significant, and thus more people pay attention .




Tungsten Alloy Manufacturer & Supplier: Chinatungsten Online - http://www.tungsten-alloy.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

 

Including rotation and radial forging forging forging forging two kinds of deformation method , it works very similar. The working principle of rotary forging is 2-4 swaging die block wrought material surrounded by high-speed rotation , while the material is swaged radially forged high-speed pulse , so that reduction of the length of the process increases . Rotary forging deformation strengthening is currently China's high-density tungsten alloy penetrators major deformation processing methods. Radial forging is a precision forging range , its working principle is to use the blank symmetrically distributed around the circumference one or more pairs hammer central axis. Radial forging work with rotary forging process is the biggest difference is radial forging billet rotation, while the rotary forging hammer is rotated . The role of radial forging and forging and hammer forging hammer different, it is not based on the effect of the pressure impact force , compressive strength is more than the pressure acting on the workpiece , resulting in plastic deformation of the metal particles and the internal the transfer , resulting in close delicate workpiece materials , thereby improving the tensile strength and elastic limit , to improve the quality of parts .

Tungsten alloy material before forging generally requires heating to 600-800 ℃, the conventional forging deformation of 10% -15 % and the maximum deformation amount is generally not more than 25% to 30% , or tungsten alloy is easy to produce damage to the need for forging stress relief annealing , the annealing temperature in the range 500-1100 ℃, generally heat - forging - annealing for one cycle .

Tungsten alloy rotary forging deformation strengthening the uneven presence of mechanical properties , the strength of the tungsten alloy core , elongation and surface hardness and strength , elongation, and there is a big difference between the hardness , surface strengthening effect than the heart portion strengthening effect . The reason is: when the rotary forging , from the entrance zone to the sizing zone tapered in this process, the metal and the degree of deformation increases started ; on the gauge is exposed only a small area of metal deformation ; the conical zone and the sizing zone cross-section of the transition metal to withstand the maximum degree of deformation , so that the conical region of the outlet and inlet material deformation speed difference increases, the result is that the metal surface causes an additional bending deformation. On the other hand , since the forging die and the blank interaction , but also the surface of the blank portion and cardiac stress state and with an old throw VOLUME degrees , the surface of metal material to withstand the shear stress and distortion and residual stresses are higher than the level of heart Ministry , thus causing the surface better than strengthening core part . Compared with the rotary forging , radial forging alloys tungsten little effect unevenness , the reason is the large amount of deformation of radial forging , generally the maximum amount of deformation of the rotary forging generally the limit. Uneven but its performance still exists . Causing the alloy forged with the edge of the core section causes uneven performance and deformation degree , the deformation is small so that deformation is focused on the edge region , while the heart is small strengthening effect , increasing the degree of deformation in performance unevenness can be improved.




Tungsten Alloy Manufacturer & Supplier: Chinatungsten Online - http://www.tungsten-alloy.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

 

Hydrostatic extrusion strain hardening deformation technology is an advanced processing technology , it is possible to obtain a 60% -80 % of the large deformation , further deformation can get more than 90% deformation , its working principle is: the bar in a high-pressure liquid medium plastically deformed under the action of the hydrostatic extrusion process , deformation of the workpiece in a high stress state three- tungsten alloy material inherent in the internal organization of microcracks and with the extrusion process for healing occurs constantly , final defects inside the material strain hardening reduced role to play .

Swaging process compared with the ordinary , hydrostatic extrusion deformation strengthening advantages: First, the amount of deformation under the same conditions , hydrostatic extrusion tungsten alloy strength is higher than the rotary swaging process tungsten alloy strength ; its Second, the hydrostatic extrusion process , particularly reasonable choice extrusion process parameters, tungsten alloy deformation capacity has been greatly improved relative terms , only once tungsten alloy extrusion can make a 60 % -80% deformation , while the rotary forging process , when a deformation amount exceeds 20% of tungsten alloy scrap rate will be greatly increased, the maximum amount of cyclic deformation rarely more than 70% , or material is easily damaged; Third , hydrostatic extrusion due to material in the deformation process is always in good lubricating conditions , small friction during the extrusion process , material deformation uniformity, large deformation makes the material extruded core part and the edge of the mechanical properties of the difference is small . Therefore, the hydrostatic extrusion process is a tungsten alloy is currently the most effective one strain hardening process . Usually sintered 93 static tensile strength of tungsten alloy 900-950MPa, elongation of 20% -30% , showing the strength of the alloy after strain hardening has been greatly improved, but reduced ductility . In the same deformation conditions, hydrostatic extrusion tungsten alloys uniform hardness uniformity, strain hardening effect is significantly better than conventional swaging process . With hydrostatic extrusion deformation increases, the enhanced role of strain hardening , strength of the material also increases, plasticity decreased , mainly due to hydrostatic extrusion process allows to obtain fibrosis tungsten alloy microstructure , thus greatly improving the strength of the alloy , and as to the plastic lower work hardening .

Hydrostatic extrusion deformation strengthening possesses such good advantage , mainly due to the hydrostatic extrusion process, the workpiece deformation at high risk of three surrounded by the compressive stress , which makes the internal organization of tungsten alloy material with the inherent microcracks and continuous extrusion process for healing to occur , and ultimately cause the material to reduce internal defects deformation strengthening the role and play . In addition, the hydrostatic extrusion process, due to the lubricating effect of high-pressure liquid material to be extruded so that the surface and the inner wall of the extrusion die to reduce friction , under the condition at higher speeds , once the formation of hydrodynamic lubrication , between the frictional shear force will be reduced to a minimum ( friction coefficient can be reduced to 0.005% -0.008 % ) , which greatly reduces the deformation of the tungsten alloy surface cracks and defects.




Tungsten Alloy Manufacturer & Supplier: Chinatungsten Online - http://www.tungsten-alloy.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

 

Cold , forged While increasing the yield strength and tensile strength , but reduces the ductility of the alloy . When the forging deformation of 30 % or more micro-cracks occur material , ductility and toughness dramatically. And when high levels of tungsten alloy , the alloy is less able to withstand the cold deformation . In order to make a high tungsten content alloys with high deformation capacity , while not causing damage to the material , therefore, developed a new thermal machining technology . Thermomechanical processing technique is characterized in that in the deformation process of the tungsten alloy is heated , the deformation at a certain temperature , a large amount of deformation , than the amount of deformation of hydrostatic extrusion is much larger ( up to 95% or more ) , and the good ductility of the alloy . Thermo-mechanical processing technologies including hot extrusion, hot-rolled and hot extruded, hot deformation with forged composite technology .

Hot Extrusion and Hot Extrusion - Forging Complex Deformation Process

Hot extrusion technique is improved by cold extrusion technology to produce a new advanced deformation process , its high density tungsten alloy preparation of large deformation strength , ductility and toughness are very good high-toughness tungsten alloy has a great location , and its working principle and roughly the same hydrostatic extrusion , hot extrusion is different working environment temperature , using the working medium from the pressure in the extrusion process transmission and lubricating effect , the working medium of a direct selection affect the stability of fluid lubrication layer formation , is generally used as a mixture of the working medium , such as graphite - a mixture of glass , when the glass is in a molten state, the media can satisfy hydrostatic extrusion on the lubrication requirements of the medium with the appropriate viscosity can form a good dynamic lubrication layer , a good solution to the problem of mold and prevent seal leakage of lubricating medium . As hot extrusion technology is at a relatively high temperature, so a greater amount of deformation processing , strengthening effect greater inhomogeneity is small, and a small pressing pressure cold extrusion , extending the service life of the mold .

Hot Deformation Process

Hot-rolled or hot - forging deformation of the composite thermal process deformation of another process . Deformation under heating , rolling and intermediate annealing after many , finally rolled into desired size and performance requirements of the material. On the brittleness of tungsten alloy materials, especially brittle solid-phase sintering of tungsten alloys, pure tungsten and tungsten - copper composite materials using this deformation process to improve the ductility and strength of materials particularly advantageous that the process of large deformation , mainly for the tungsten alloy material deformation processed into thin , thin slices. The tungsten content is low ( 70% -80% ) of the tungsten alloy , the tungsten content is low , liquid phase sintering is difficult to control to obtain a uniform thickness can be rolled bar . The alloy by solid phase sintering , and hot rolling , the alloy can 30070-35 % elongation , after rolling, can be a sheet having a thickness of 0.15mm thick .




Tungsten Alloy Manufacturer & Supplier: Chinatungsten Online - http://www.tungsten-alloy.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

 

Tungsten is a brittle metal with a very high melting point. Out of all of the elements only carbon has a higher melting point, and tungsten's melting point is higher than 3300 degrees Celsius. Tungsten is also very hard and scratch-resistant, and metal tungsten rings are very popular. Many men wear them as their wedding rings because they don't scratch and always look new. There are a variety of types of metal tungsten.

Pure Metal Tungsten
Tungsten is element W on the periodic table. It has an atomic weight of 183.84 and its atomic number is 74. It has the highest melting point of any metallic element. In its pure form, it is light gray or white and very brittle. It can be cut with a simple saw or formed into various shapes. Because of this, and its high melting point, tungsten is used in the filaments of a variety of light emitting products such as light bulbs and televisions. Pure metal tungsten is generally obtained from wolframite and scheelite, a mineral. The process by which tungsten is extracted from wolframite was pioneered by two Spanish chemists and mineralogists in 1783.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

Tungsten carbide has become increasingly popular and in high demand throughout the decades, now presently producing up to almost 30,000 tons annually.

The Present Day
Isostatic pressure sintering, led to the development of tungsten which was even harder than before. Tungsten is used in tools, mining, weaponry and even jewelry.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn