The CT960 universal internal grinding machine from Studer features a fully interpolating B axis and four spindles for complex grinding tasks.

The CT960 universal internal grinding machine from United Grinding features a fully interpolating B axis and four spindles for complex grinding tasks. It is suitable for machining small- to medium-sized parts including die plates, spring collets, toolholding fixtures, hydraulic components, medical components and thread ring gages in materials including tool steel, tungsten carbide, ceramic and glass.

The grinding spindle turret features a dynamic direct drive said to enable faster swiveling times. Workpieces can be completely machined in the same clamping. The swiveling time is less than 2 sec. for 90 degrees, and less than 3 sec. for 270 degrees. The angular position of the grinding spindles is infinitely variable from -5 degrees to +30 degrees in all four positions. The automatic B axis of the workhead features a swiveling range of +61 to -91 degrees. The B axis has no contact surface, and is completely closed and virtually wear-free. A coolant distributor is designed to ensure well-regulated internal conditions.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Tungsten News & Tungsten Prices, WML Version: http://m.chinatungsten.com

2013 is here and this is my our year. Well, maybe not year, but in two months, I will be taking that walk down the aisle, looking my honey in the eye as I say:

“I Do.”

Those two words are what every little girl dreams of saying to and hearing from her Prince Charming, as she stands in front of her family and friends on one of the biggest days of her life. However, the road to the alter isn’t always one of bliss; a lot of planning goes into making the wedding day a special one, planning that can be stressful and lead to lots of headaches (but only if you let it!).

Working with the right vendors will help to alleviate that stress and make the planning process much easier. As I near the big day, I will share some of the great vendors I’ve had the pleasure of working with, who have helped make planning for my wedding an exciting event! Check back for updates as we near the big day!

Ring Engstrom Jewelers: The Bling

Tungsten rods with evaporated crystals, partially oxidized with colorful tarnish. Purity 99.98 %, as well as a high pure (99.999 % = 5N) 1 cm3 tungsten cube for comparison.

This element  tungsten, which has the chemical symbol W and the atomic number 74. The name is derived from Swedish and translates as "heavy stone", in recognition of one of this metal's more obvious qualities.

Pure tungsten is silver-coloured, very hard, and has an extremely high melting point (3422 °C / 6192 °F) -- the highest for any metal and second only to carbon (3550°C / 6422°F). Tungsten is quite rare on Earth and occurs in the wild only in a number of minerals.

By now, I suppose that you are wondering where the chemical symbol, W, came from. Although this element is known as tungsten in many English and French speaking countries, a number of European countries know it as wolfram, a word derived from German, which translates roughly as "wolf's froth" or "cream" -- a reference to the large amounts of tin consumed by tungsten extraction.

Recycling, reusing and reducing are all ways in which Europeans are assisting in efforts to reduce greenhouse gas (GHG) emissions. It is a far cry from the days when we threw everything away without thought. Now we know it is the simple solutions that are making the difference. One example is lighting, which accounts for 14 % of electricity consumption in the EU. As a result, incandescent bulbs are being phased out in Europe and replaced with new energy-efficient and eco-friendly lighting technologies.

The EU has committed to cutting its GHG emissions by at least 20 % by 2020 and to improving energy efficiency also by 20 %. As part of this effort, the European Commission launched its Green Paper on 'Lighting the Future - Accelerating the deployment of innovative lighting technologies'. This in turn is raising awareness of the benefits of light-emitting diode (LED).

This Green Paper is part of the Digital Agenda under the Europe 2020 strategy for smart, sustainable and inclusive growth. It sets out the key issues to be addressed in a European strategy aimed at accelerating the deployment of high-quality solid state lighting (SSL) for general lighting. Its main objective is to help Europe achieve its key energy efficiency, industrial and innovation policy objectives.

Few tools are as invaluable to a chef as the right knife. And, to ensure that the tool keeps its cutting edge, a knife sharpener is equally important. Sharpeners come in both manual and electric models.

An electric knife sharper is better for knives used to cut bones or frozen foods, where a razor edge isn't needed. A manual sharpener will give a precise cutting edge for foods such as meats and tomatoes. Some models offer both manual and electric sharpening.

An ideal knife sharpener starts with a hard, abrasive surface - such as diamond, tungsten carbide or high-alumina ceramic - then uses steel or other ceramics for polishing. Sharpeners made of diamond or tungsten carbide tend to be more expensive; they sharpen quickly but pose a danger to some metals. Among manual models, butcher's steel and ceramic sticks are good for everyday use. For precision in a manual model, look for one made with diamond, tungsten carbide or whetstone. Stone sharpeners, safe for most knives, wear out over time.

Ferro-Tungsten

Ferro-tungsten is a master alloy for the production of tungsten-containing steels.  The raw materials for ferro-tungsten production are rich ore or ore concentrates of wolframite or scheelite.  Also artificial scheelite or soft scrap can be used.  The tungsten trioxide in these compounds can be reduced either carbothermically in electric arc furnaces or metallothermically by silicon and/or aluminum.  Also a mixed carbothermic-silicothermic production is in use.

Commercial ferro-tungsten contains between 75 and 85% W.  It has a steel grey appearance and a fine-grained structure consisting of FeW and Fe2W.  It is supplied in 80–100 mm lumps.

Melting Base

Melting Base is another master alloy in tungsten steel production. It can have various compositions according to the tungsten scrap material in use. The tungsten content varies depending on type between 10 and 38% besides iron and sometimes 5.5% Mo and also 5 to 10% Co.

Different types of scrap materials are mixed to meet the required composition. Reductive melting is done in electric arc furnaces and the melt is finally granulated by casting on a rotating disc and quenching in water (size <10 mm).

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com

Tel.: 86 592 5129696; Fax: 86 592 5129797

Email: sales@chinatungsten.com

PC Version: Tungsten News & Tungsten Prices: http://news.chinatungsten.com

3G Version :Tungsten News & Tungsten Prices : http://3g.chinatungsten.com

WML Version:Tungsten News & Tungsten Prices: http://m.chinatungsten.com

Tungsten carbide powder is the intermediate in the line from W powder to cemented carbides.  It can be produced from different raw materials and by different processes.  By far the biggest percentage is manufactured by the conventional method - carburization of tungsten powder - and covers the widest range of powder qualities in regard to average particle size (0.15–12µm).  All other methods in use yield very fine or very coarse powder grades.

The conventional process of carburisation comprises mixing of the respective tungsten powder of desired particle size with high purity carbon (lamp black or graphite) and reacting at temperatures between 1,300 to 1,600°C in hydrogen atmosphere.  The average particle size and particle size distribution of the original tungsten powder determine size and distribution of the WC powder.

The final carbon content of the WC Powder depends on the production mode of the hardmetal producer and is one item of the rigid specification, and varies from slightly sub-stoichiometric to stoichiometric (6.13% C) to slightly over-stoichiometric.  But not only is the carbon content specified but also a series of physical properties including: average particle size, particle size distribution, apparent (bulk) density and homogeneity.

High temperature carburised WC powders (1,700–2,200 °C) are usually coarse 10 to 50µm, but sometimes also 5 to 10µm grades are treated that way. The percentage of high temperature WC is small.

Tungsten carbide powder is packaged in sealed polyethylene-lined steel drums.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com

Tel.: 86 592 5129696; Fax: 86 592 5129797

Email: sales@chinatungsten.com

PC Version: Tungsten News & Tungsten Prices: http://news.chinatungsten.com

3G Version :Tungsten News & Tungsten Prices : http://3g.chinatungsten.com

WML Version:Tungsten News & Tungsten Prices: http://m.chinatungsten.com

Technical tungsten powder qualities are prepared by hydrogen reduction and are available in average particle sizes from 0.1 (100nm) to 100µm.  The reduction process is, in some respects, unique.  It offers the possibility to produce tungsten powder of any desired average particle size within the above limits only by changes in reduction conditions.

The whole palette of particle sizes finds applications in cemented carbide production.  The main portion of tungsten powder is directed to that manufacture.  Starting tungsten powder for ductile tungsten and powdermetallurgically produced tungsten alloys covers particle sizes between 2 and 6µm.  Extremely coarse powder gained by screening to separate any finer particles has excellent flow characteristics and is used in plasma spraying.

The purity of the tungsten powder is of particular importance in all applications and is mainly influenced by the purity of the original APT. Typical upper limits of foreign element concentrations in µg/g are:

Co, Cu, Mg, Mn, Pb ≤ 2

Al, Fe, Ni, Si, Ca, Cr, Sn ≤10

Mo ≤ 20

The crucial physical properties are average particle size, particle size distribution, apparent, tap and compact or green density, specific surface area, degree of agglomeration and morphology. They are to a certain extent related to each other and can be influenced between limits by the oxide properties and the reduction conditions.

Tungsten powder customers have in most cases very rigid specifications.

Tungsten metal powder is packaged in sealed polyethylene-lined steel drums.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com

Tel.: 86 592 5129696; Fax: 86 592 5129797

Email: sales@chinatungsten.com

PC Version: Tungsten News & Tungsten Prices: http://news.chinatungsten.com

3G Version :Tungsten News & Tungsten Prices : http://3g.chinatungsten.com

WML Version:Tungsten News & Tungsten Prices: http://m.chinatungsten.com

Intermediates, such as tungsten trioxide, tungsten blue oxide, tungstic acid, and ammonium metatungstate can be derived from APT as shown below, either by partial or complete thermal decomposition or by chemical attack.

Tungsten Trioxide (WO3)

Tungsten trioxide is almost exclusively manufactured by calcination of APT under oxidising conditions (in air).  WO3 is one of the most important, highly pure intermediates for the production of other tungsten compounds including tungsten metal powder.  In the latter application, it was substituted to a large extent by tungsten blue oxide. Because of its bright yellow colour it is used as a pigment in oil and water colours. It is employed in a wide variety of catalysts, most recently for the control of air pollution and industrial hygiene (DeNOx).

Tungsten trioxide particles are pseudomorphous to APT; which means the particles have the same shape and size as the former APT crystals, but consist of very small WO3 grains.  The yellow powder is packaged in sealed polyethylene-lined steel drums and individual packaging (20 to 50kg).

Tungsten Blue Oxide (TBO; WO3-X)

TBO is manufactured by calcination of APT under more or less reducing conditions which vary from producer to producer. TBO is not a chemically defined compound, but consists of various different constituents, like trioxide, tungsten bronzes and different lower tungsten oxides. The relative amount of these compounds in TBO depends on the calcination parameters, (the parameter x typically varies between 0.01 and 0.10).

TBO is the most important precursor in the line from oxide to W and WC powder. The colour varies between deep dark blue to blue, faint blue and green blue. Also the TBO particles are pseudomorphous to the original APT crystals, as described for tungsten trioxide.

Tungstic Acid H2WO4.nH2O

Tungstic acid, formally the most important intermediate in tungsten chemistry, is now exclusively manufactured from APT, in order to make use of the high purity APT level.  For that purpose an aqueous APT slurry is treated with hydrochloric acid and tungstic acid is precipitated, which is then filtered, washed and dried.  Tungstic acid has a very high active surface and is only used in small quantities for special purposes such as the production of ultrafine W and WC powders and tungsten chemicals.

Tungstic acid is a fine yellow powder and is packaged in sealed polyethylene-lined steel drums.

Ammonium Metatungstate (NH4)6[H2W12O40].3H2O

Ammonium Metatungstate (NH4)6[H6W12O40].3H2O has gained increasing usage for a variety of applications, especially chemicals and catalysts, because of its excellent solubility in water. The usual commercial product contains 3 to 4 molecules of water. On an industrial scale, it is obtained by partial thermal decomposition or partial replacement of ammonium ions by hydrogen ions using selective ion exchange and subsequent evaporation.

AMT is a white crystallised powder. Between 200 and 300°C, it converts to the anhydrous form. Further decomposition leads to WO3. At 80°C, 2,200 g WO3/l are dissolved in water.

AMT is used for the preparation of heteropoly acids, which consist of inorganic oxyacids of phosphorous or silicon and that of tungsten. Such compounds are attractive catalysts for many kinds of organic reactions.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com

Tel.: 86 592 5129696; Fax: 86 592 5129797

Email: sales@chinatungsten.com

PC Version: Tungsten News & Tungsten Prices: http://news.chinatungsten.com

3G Version :Tungsten News & Tungsten Prices : http://3g.chinatungsten.com

WML Version:Tungsten News & Tungsten Prices: http://m.chinatungsten.com

Ammonium Paratungstate (NH4)[H2W12O42].4H2O is the most important precursor for the majority of tungsten products. Exceptions are only products of melting metallurgy and Menstrum WC produced directly from ore concentrates.

All other intermediates such as tungsten trioxide, tungsten blue oxide, tungstic acid and ammonium metatungstate can be derived from APT, either by thermal decomposition or chemical conversion. 

APT is a white crystallized powder having average crystal size between 30 and 100 µm. Especially crucial for the quality is the purity. Typical levels of todays commercial APT are (upper limits in µg/g):
Al 1-7, As 5-10, Bi 0.5-1, Ca 1-10, Co 1-10, Cr 1-10, Cu 1-3, Fe 3-10, K 2-10, Mg 1-7, Mn 1-10, Mo 5-30, Na 5-10, Ni 1-7, P 5-7, Pb 1-5, S 5-7, Si 1-10, Sn 1-10, Ti 3-10, and U 3-10. APT is packaged in polyethylene-lined drums or woven bags up to 1 ton.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com

Tel.: 86 592 5129696; Fax: 86 592 5129797

Email: sales@chinatungsten.com

PC Version: Tungsten News & Tungsten Prices: http://news.chinatungsten.com

3G Version :Tungsten News & Tungsten Prices : http://3g.chinatungsten.com

WML Version:Tungsten News & Tungsten Prices: http://m.chinatungsten.com