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The Basics of Nonferrous Metallurgy

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Refractory Metals: Part One

As a group they provide a number of unique characteristics – such as resistance to high heat, corrosion and wear – making them useful in a multitude of applications.
Refractory metals have one characteristic in common: an exceptionally high melting point. Tungsten, for example, melts at 3410°C (6170°F), which is more than double that of iron and ten times that of lead.

Refractory Metals: Part Two

Tantalum is soluble in fused alkalis, insoluble in sulfuric, hydrochloric, and nitric acids, and soluble in hydrofluoric acid. It ignites in air to form tantalum pentoxide (sometimes referred to as tantalum (V) oxide or tantalic acid anhydride).
Tantalum belongs to the group of metals that includes vanadium and niobium. It occurs mainly in the mineral tantalite (see Columbite), FeTa₂O₆.

Refractory Metals: Tungsten and Tungsten alloys

Tungsten is consumed in four forms: tungsten carbide, alloying additions, pure tungsten, tungsten-based chemicals.
Tungsten carbide accounts for about 65% of tungsten consumption. It is combined with cobalt as a binder to form the so-called cemented carbides, which are used in cutting and wear applications. Metallic tungsten and tungsten alloy mill products account for about 16% of consumption. In wire form, tungsten is used extensively for lighting, electronic devices, and thermocouples. Tungsten chemicals make up approximately 3% of the total consumption and are used for organic dyes, pigment phosphors, catalysts, cathode-ray tubes, and x-ray screens.

Silicon Carbide (SiC)

Originally produced using a high temperature electro-chemical reaction of sand and carbon, silicon carbide is recognized as one of the most promising structural materials due to its excellent high temperature strength, good oxidation, and thermal shock resistance to name just a few advantages.
The secret of these excellent attributes lies in the composition of the material which is composed of tetrahedra of carbon and silicone atoms which inherently display extremely strong bonds within the crystal lattice.

Silver and Silver Alloys

Silver and its alloys represent crucial materials in both decorative and industrial applications. While traditionally known for jewelry and tableware, over half of global silver demand now comes from industrial uses, particularly in electronics.

Sintered Aluminum Powder (SAP)

Sintered aluminum powder alloys have properties quite different from those of material fabricated by conventional techniques. The oxide that forms immediately on the surface of aluminum is not reduced back to metal during sintering and the resulting powder product contains a substantial amount of oxide. This oxide prevents grain growth and movement of dislocations at the boundaries or through them and produces high strength, high creep resistance and insensitivity to high-temperature exposure.