Refractory Metals

Yigal Sharabi

<div class="jnlc-container" id="jnlc-container"> <img src="http://static2.shopify.com/s/files/1/0014/5692/files/Refractorymetal.jpg" width="360" height="200" class="floatLeft" /> Refractory Metals Refractory metals are a class of metals extraordinarily resistant to heat, wear, and corrosion. These properties make them useful in many applications. Household incandescent bulbs contain refractory metals in their tungsten filaments, and nearly all manufactured goods, particularly those containing metal or electronics, contain or were produced using refractory metals. The list of refractory metals include Titanium, Tantalum, Hafnium, Vanadium, Zirconium, Tungsten, Molybdenum, Niobium, Tantalum and Rhenium. Refractory metals are used in lighting, tools, lubricants, nuclear reaction control rods, as catalysts, and for their chemical or electrical properties. Because of their high melting point, refractory metal components are never fabricated by casting. The process of powder metallurgy is used. Powders of the pure metal are compacted, heated using electric current, and further fabricated by cold working with annealing steps. Refractory metals can be worked into wire, ingots, bars, sheets or foil. In the jewelry industry, titanium, tantalum and niobium are usually the only refractory metals used. Their fabrication by methods requiring intensely high heat presents problems that are generally beyond the scope of the jeweler. These processes require the use of equipment and techniques not generally employed by jewelers and other craftsperson's. They can, however, be cold worked to some degree. Their main attraction for jewelers lie in the fact that they all have the capacity of optical interference surface coloring, where attractive, durable and bright-colored surface oxide films develop due to their reaction with oxygen under the controlled application of heat or anodic oxidation. These colors are predictable, easily reproducible and develop from the metal itself without the use of dyes or pigments. They are also highly resistant to tarnishing. <a href="/pages/metals"><img src='http://static1.shopify.com/s/files/1/0014/5692/files/Back1.png' alt='' /></a></a> </div>

2008-07-17T09:42:08-04:00

refractory-metals 351062

2008-07-17T09:42:08-04:00

145692

Refractory Metals 2008-11-05T13:44:14-05:00 <notextile> <div class="jnlc-container" id="jnlc-container"> <img src="http://static2.shopify.com/s/files/1/0014/5692/files/Refractorymetal.jpg" width="360" height="200" class="floatLeft" /> Refractory Metals Refractory metals are a class of metals extraordinarily resistant to heat, wear, and corrosion. These properties make them useful in many applications. Household incandescent bulbs contain refractory metals in their tungsten filaments, and nearly all manufactured goods, particularly those containing metal or electronics, contain or were produced using refractory metals. The list of refractory metals include Titanium, Tantalum, Hafnium, Vanadium, Zirconium, Tungsten, Molybdenum, Niobium, Tantalum and Rhenium. Refractory metals are used in lighting, tools, lubricants, nuclear reaction control rods, as catalysts, and for their chemical or electrical properties. Because of their high melting point, refractory metal components are never fabricated by casting. The process of powder metallurgy is used. Powders of the pure metal are compacted, heated using electric current, and further fabricated by cold working with annealing steps. Refractory metals can be worked into wire, ingots, bars, sheets or foil. In the jewelry industry, titanium, tantalum and niobium are usually the only refractory metals used. Their fabrication by methods requiring intensely high heat presents problems that are generally beyond the scope of the jeweler. These processes require the use of equipment and techniques not generally employed by jewelers and other craftsperson's. They can, however, be cold worked to some degree. Their main attraction for jewelers lie in the fact that they all have the capacity of optical interference surface coloring, where attractive, durable and bright-colored surface oxide films develop due to their reaction with oxygen under the controlled application of heat or anodic oxidation. These colors are predictable, easily reproducible and develop from the metal itself without the use of dyes or pigments. They are also highly resistant to tarnishing. <a href="/pages/metals"><img src='http://static1.shopify.com/s/files/1/0014/5692/files/Back1.png' alt='' /></a></a> </div> </notextile>