Stabilization of Cobalt-Chromium Alloy

Cobalt-Chromium Alloy in China, mainly Cobalt-Chromium Alloy superalloys more in-depth and thorough. Unlike other superalloys, Cobalt-Chromium Alloy superalloy does not consist of an ordered precipitated phase that is firmly bonded to the substrate, but instead consists of a matrix of fcc that is solid-solution strengthened and a small amount of carbides distributed in the matrix. Casting Division Stanley superalloy is to a large extent rely on carbide strengthening. Pure cobalt crystals at 417 ° C are densely packed hexagonal (hcp) crystalline structures that are converted to fcc at higher temperatures. In order to avoid this conversion of Cobalt-Chromium Alloy superalloy in use, virtually all Cobalt-Chromium Alloys are nickel alloyed to stabilize the tissue from room temperature to the melting temperature.

From the late 1950s to the late 1960s, the United States has widely used four types of Foundry Stellite: WI-52, X-45, Mar-M509 and FSX-414. Deformation Division too much alloy for the plate, such as L-605 for the production of combustion chambers and catheters. HA-188, which appeared in 1966, has improved oxidation resistance due to lanthanum contained therein. Soviet Union used to make guide vane Cobalt-Chromium Alloy ΠK4, equivalent to HA-21. Cobalt-Chromium Alloy should consider the development of cobalt resources. Cobalt is an important strategic resource. Cobalt is lacking in most countries in the world. As a result, the development of Cobalt-Chromium Alloy is limited.

Pure cobalt crystals at 417 °C are densely packed hexagonal (hcp) crystalline structures that are converted to fcc at higher temperatures. In order to avoid this conversion of Cobalt-Chromium Alloy superalloy in use, virtually all Cobalt-Chromium Alloys are nickel alloyed to stabilize the tissue from room temperature to the melting temperature. Cobalt-Chromium Alloy has a flat fracture stress-temperature relationship, but exhibits superior hot corrosion resistance at temperatures above 1000 °C compared to other high temperatures, probably because of the higher chromium content of the alloy, this is the feature of Cobalt-Chromium Alloy

Cobalt-Chromium Alloy is Manufactured by the Soak Method

Cobalt-Chromium Alloy original pure tungsten rocket lance nozzle can no longer meet such conditions of use, when other materials can not meet the requirements. In the early 1960s, R.E.Mott and G.G.Goetel and others re-studied the tungsten-silver alloy according to the concept of “sweat cooling”, including the mechanism of perspiration, thermal shock resistance Sex, system preparation process and performance research. The mid-1960s developed tungsten silver (W-10Ag) nozzle, equipped with “Polaris A-3” missiles. Although the tungsten silver nozzle nozzle earlier than the tungsten copper, but because of its high price and other nozzle material developed successfully, then no further development. Currently tungsten silver material is mainly used for electrical switch contacts (contacts), the contact resistance of tungsten copper material is smaller, more for contactors.

Silver and tungsten are insoluble in both liquid and solid state. Preparation of silver tungsten alloy can only be made by sintering powder metallurgy material, can also be used extrusion method. Material is characterized by high hardness, anti-arc erosion, anti-adhesion and anti-welding ability. Made by powder metallurgy. More than 60% of the tungsten alloy used in many production methods. At very high temperatures, such as above 3000 ° C, the copper in the alloy is liquefied and vaporized, absorbing large amounts of heat and reducing the surface temperature of the material. So this kind of material is also called metal sweat material. Since tungsten and copper are incompatible with each other, tungsten-copper alloys have low expansibility, wear resistance, corrosion resistance, and high electrical and thermal conductivity of copper, and are suitable for various machining processes.

Tungsten copper alloy according to user requirements for the ratio of tungsten and copper production and size of the processing. Tungsten copper alloy powder metallurgy process is generally the first powder – mixing ingredients – pressing molding – sintering infiltration. Tungsten copper is the use of high-purity tungsten powder excellent metal properties and high purity copper powder plasticity, high conductivity, etc., by hydrostatic molding, high temperature sintering, the infiltration of copper refining process of composite materials. Arc-breaking performance, conductive thermal conductivity, thermal expansion, high temperature does not soften, high strength, high density, high hardness. Cobalt-Chromium Alloy Bushing,Saw Tips,Valve Seats Manufacturer –

Preparation of Silver Tungsten

Preparation of Silver Tungsten alloy and tungsten copper alloy the same. Because of the high melting point of tungsten and silver can not be mutual melting, it can not be prepared by traditional methods, the preparation of tungsten silver alloy powder metallurgy method must be used. The application of tungsten silver alloy and tungsten copper alloy is also relatively similar, tungsten silver alloy used as a solid rocket nozzle throat lining. In the electrical switch, tungsten silver alloy more for lower voltage circuit breakers, automatic switches, contactors and other requirements of good oxidation resistance, conductive thermal conductivity, contact size smaller, frequent opening and closing of the occasion.

W-Ag alloy is widely used in high temperature materials, high voltage switchgear alloy, electric processing electrodes, microelectronic materials, as components and components widely used in aerospace, aviation, electronics, power, metallurgy, machinery, sports equipment and other industries .

High temperature oxidation resistance of silver-tungsten alloy, at room temperature does not react with the acid, but in a mixed acid nitric acid and hydrofluoric acid dissolved at 1000 ℃ in nitrogen atmosphere to form nitrides. Mechanical manufacturing according to advanced technology drawings after conversion in the production of lead bronze centrifugal casting technology, however, customs can not get foreign orders, due to the price is too high, and some use of alternative copper alloy production, resulting in life is too short, causing great Troubled.

In the actual production process, as long as the reasonable choice of surfacing process, surfacing layer weld metal to avoid chemical loss and impurities infiltration, dilution rate control under the premise of the quality and performance of the deposited can be guaranteed. In the course of this alloy carbide phase precipitation continued to become brittle.

Preparation of silver tungsten powder metallurgy, more than 60% of the tungsten alloy after immersion greater capacity. Mainly used for low voltage power switch, lifting switch, switch locomotive, high current switch contacts, heavy duty relays, air circuit breakers and other cobalt. These can improve wet silver tungsten, in order to reduce the ability to contact resistance. Cobalt-Chromium Alloy –