Cobalt Alloys

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Cobalt Alloys


alloys based on cobalt; used primarily in the manufacture of components operating at high temperatures, such as blades for turbojet engines.

“Casting” cobalt alloys are alloys of the Co-Cr-C-X system, where × is tungsten, molybdenum, niobium, or nickel, that exhibit good casting properties. Since hardening of these alloys is effected mainly by the carbide phases, they contain 0.2–1.0 percent carbon. The addition of boron improves the casting properties of the alloys but it may decrease their weldability.

Cobalt alloys are highly resistant to thermal fatigue. The average thermal expansion coefficient is low [(15.9–16.5) × 10-6 1/ °C] within the temperature range of 20°–870°C. The most heat-resistant cobalt alloys maintain their durability at temperatures up to 1100°C. Long-term ultimate strength Cobalt Alloys meganewtons per sq m, or 7 kilograms-force per sq mm. Cobalt alloys of the Co-Cr-Ni-Mn system, which contain up to 50 percent Co (deformable cobalt alloys), exhibit high resistance to thermal fatigue and can be worked under pressure. Cobalt alloys called stellites (30 percent Cr, as well as W, Si, and C) are used for hard-facing of machine tools and parts (without subsequent heat treatment) to increase their wear resistance. As a basic or alloying element, cobalt is one of the magnetic materials.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Lee Spring's expertise in materials from steel through stainless steel, plastic composite, Elgiloy (cobalt-chrome nickel) and many other nickel and cobalt alloys such as Inconel, Nimonic, Hastelloy, Monel, also phosphor bronze and beryllium copper, will be available to engineers whatever their application or area of interest.
This time, new cobalt alloys were developed to replace the platinum.
Among the topics are the creation of a new class of nanocomposite coatings with increased crack resistance and hardness using innovative beam technologies, modeling the spark plasma sintering of powder materials by the finite element method, the selective laser melting of three-dimensional structures produced from heat-resistant cobalt alloys, and determining the true temperature in the selective laser melting of metal powder using an infrared camera.
The cobalt alloys also present interesting magnetic properties making them candidates for disk storage media.
Cobalt alloys are erosion- and corrosion-resistant metals designed to retain high strength during long-term exposure to high temperatures.
Sandvik Materials Technology, a world-leading manufacturer of high value-added products in advanced stainless steels and special alloys, and ThyssenKrupp VDM, one of the world's leading suppliers of nickel and cobalt alloys, titanium and other high-performance materials, have announced that they have agreed on a cooperation on the production and sale of zirconium products.
Lack of information on manufacturing cobalt alloys and uncertain limits of high speed domain found in bibliography for superalloys--from 200m/min (Schultz) to 400m/min (Denkena et.
The remaining chapters address passivity, iron and steel, effect of stress, atmospheric corrosion, corrosion in soils, oxidation, stray-current corrosion, cathodic protection, metallic coatings, inorganic coatings, organic coatings, inhibitors and passivators, treatment of water and steam systems, alloying stainless steels for corrosion resistance, copper and copper alloys, aluminum and aluminum alloys, magnesium and magnesium alloys, nickel and nickel alloys, cobalt and cobalt alloys, titanium, zirconium, tantalum, and lead.
Both the SAC 305 and cobalt alloys exhibited no deterioration in solder attachment integrity after 1,000 thermal cycles (Figure 1).