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Tungsten Rod

Tungsten Rod

Date posted: October 6, 2017 // Tungsten

Identified in the periodic table by the seemingly unrelated symbol W, it is derived from the initial letter of Wolfram, the name first given by its discoverers to a metal that has since proved to be one of the most important to modern industry. Although its classification as a refractory metal is shared by a number of others, including niobium, molybdenum and titanium, its exceptional hardness, high melting point and resistance to corrosion set it apart.

Its exceptional properties have seen both the pure metal and various alloys of tungsten, in the form of rods, sheets and wire, providing the ideal material from which to manufacture all manner of items for which exceptional durability, electrical conductivity, heat and corrosion resistance, or some combination of these properties, is crucial. In addition, this extraordinary metal plays an essential role in several metallurgical processes.

Supplied in the format that is best suited to the task for which the metal will be used, the bulk of the demand tends to be for tungsten rod both in its unadulterated form or alloyed with lanthanum. The act of doping the refractory metal with lanthanum oxide, results in improved creep resistance, higher recrystallization temperature, lower electron work function and considerably easier machinability. Together, these improvements serve to render the alloyed form markedly more suitable for use as an ion source, as well as for the manufacture of both lamp and welding electrodes. In addition, the alloy also outperforms the pure metal in terms of its ductility and stability at high temperature.

Whether in the form of wire, sheets or a tungsten rod, one of the most striking features of the metal is its melting point which, at a massive 3422°C, is surpassed only by the non-metallic element carbon at 3550°C. This makes it the perfect choice of material with which to manufacture the high temperature furnaces used in to smelt other metals and glass. Interestingly, like the highly-prized allotropic form of carbon commonly described as a girl’s best friend, the refractory metal can only be worked on with tools made from the same material.

That exceptional strength is put to the test in the drill bits that can penetrate other metals with the ease of a hot knife slicing through butter and even those filaments in the, now largely obsolete, incandescent light globes seemed to last forever. Such applications are just a few of the many ways in which tungsten rod is used today.

One area in which the metal has gained prominence is that of high temperature welding. In a process known as gas tungsten arc welding or GTAW, the inert gasses argon or helium are used to shield the weld area from possible oxidation, while current passed through the non-consumable tungsten electrode generates a plasma arc composed of ionised gas and vaporised metal. It is a process favoured by the aerospace industry due to the superior control it allows over the weld area as compared to alterative welding procedures.

Whatever the application, the quality of the metal or metal alloy used will be crucial to its success. That quality is assured when purchasing tungsten rod, sheets, plates or wire manufactured by Plansee and available in South Africa from Labotec Industrial Technologies. For more information, please feel free to contact us today.