In order to create an arc and transfer the welding current to the base material being welded, TIG welding requires the use of a tungsten electrode. Tungsten is a non-consumable electrode that has the highest melting point of any metal (3,410 degrees Celsius or 6,170 degrees Fahrenheit). So in theory it can’t melt, right? Wrong.

One of the most common tungsten troubles is excessive consumption. On AC (alternating current) applications, such as TIG welding aluminum, setting the balance control toward the electrode positive (EP) provides good cleaning action (removal of oxides) around the weld. However, it can also cause the tungsten to melt. The best remedy is to set the balance control toward the electrode negative (EN), as this increases the amount of heat going into the work piece as opposed to the tungsten. Seventy to eighty percent toward the electrode negative is a good range. When TIG welding materials like steel, stainless steel, inconel or other ferrous materials using DC (direct current), also set the power source to the electrode negative mode.

Another cause of excessive tungsten consumption is using too high of amperage for a given diameter of tungsten, regardless of whether it is on an AC or DC application. Always follow the tungsten manufacturer’s recommended operating parameters for the diameter being used.

Finally, incorrect or contaminated shielding gas and loose or cracked hose fittings can all cause excessive tungsten consumption. Take care to use clean, pure Argon and be certain all hoses are intact and fittings are tightened prior to welding.

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Since the dawn of tungsten chemistry at the end of the 18th century, coloured tungsten compounds have attracted people.  The first to mention the beauty of yellow tungsten oxide, Rudolf Erick Raspe, had already proposed it as an artist's colour.  Later, Friedrich Wöhler examined the group of colourful tungsten bronzes.

By the end of the 19th century, tungsten salts were used to make coloured cotton fast or washable and to make clothes used for theatrical and other purposes non-inflammable.

In the 1930's, new applications arose in the oil industry for the hydrotreating of crude oils and, in the sixties, new catalysts were invented containing tungsten compounds to treat exhaust gases.

Over the years, however, the amount of tungsten used for these applications has remained small compared to steel, mill products or cemented carbides.

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Tungsten heavy alloys generally are refractory metal, which have two-phase composites consisting of W-Ni- Fe or W-Ni- Cu or even W-Ni-Cu-Fe, some tungsten alloy is added Co、Mo、Cr, etc. They have very high melting point and have a density twice that of steel and are more than 50% heavier than lead. Tungsten content in conventional heavy alloys varies from 90 to 98 weight percent and is the reason for their high density (between 16.5 and 18.75 g/cc).

Nickel, iron and copper serve as a binder matrix, which holds the brittle tungsten grains together and which makes the alloys ductile and easy to machine. Nickel-iron is the most popular additive, in a ratio of 7Ni:3Fe or 8Ni:2Fe (weight ratio). The conventional processing route for tungsten heavy alloys includes mixing the desired amount of elemental powders, followed by cold pressing and liquid phase sintering to almost full density. The matrix alloy melts and takes some tungsten into solution during liquid phase processing, resulting in a microstructure through which large tungsten grains (20–60µm) are dispersed in the matrix alloy.

The as-sintered material often is subjected to thermo mechanical processing by swaging and aging, which results in increased strength and hardness in the tungsten heavy alloys.


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Tungsten alloys are materials with a high tungsten content and low amounts of NiFe (binder material). They show similar high densities as pure tungsten, but they are much easier to machine.Tungsten Heavy Alloys are characterised in particular by their excellent strength and ductility.

Advantages tungsten heavy alloys:  
  high density from 17.0 to 18.5 g/cm3
  high absorption capacity against X-rays and gamma rays
  good machinability  
  high Young's modulus and very good mechanical properties
  harmless to the health and environment

Application of tungsten heavy alloys:  
  protection shields for nuclear radiation
  counter weights for the engine construction
  aerospace
  mechanical engineering
  fine mechanical technology
  forming
  sports


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