Classification of rare earths
1) Light rare earth (also known as 铈 group): 镧 , 铈, 镨 , é’• , é’·, é’ , é“• , é’† .
2) Heavy rare earth (also known as é’‡ group): 铽 , é• , é’¬ , é“’ , é“¥ , 镱 , é•¥ , é’ª , é’‡.
The difference between the 铈 group and the 钇 group is because the rare earth mixture obtained by separation of minerals is often named after the ratio of lanthanum or cerium.
Rare earth metals (rare earth metals), also known as a rare earth element, is a general term for a group â…¢B periodic table scandium, yttrium, lanthanides 17 elements, commonly represented by R or RE. Their names and chemical symbols are é’ª (Sc), é’‡ (Y), 镧 (La), 铈 (Ce), 镨 (Pr), é’• (Nd), é’· (Pm), é’ (Sm), é“• (Eu ), Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu. Their atomic numbers are 21 (Sc), 39 (Y), 57 (La) to 71 (Lu).
é“’ (Er) In 1843, Mossund of Sweden discovered the Erbium. The optical properties of cockroaches are very prominent and have always been a concern:
(1) The light emission of Er 3 + at 1550 nm is of special significance because the wavelength is exactly at the lowest loss of the optical fiber of the fiber communication. The erbium ion (Er 3 + ) is excited by the light of 980 nm and 1480 nm, and the ground state is 4I15. /2 transition to high energy state 4I13/2, when the high energy state Er 3 + re-jumps back to the ground state, it emits light of 1550nm wavelength. The quartz fiber can transmit light of different wavelengths, but different light light decay rates are different. The light in the 1550 nm band has the lowest light attenuation rate (0.15 dB/km) when transmitted in a quartz fiber, and is almost the lower limit attenuation rate. Therefore, when fiber communication is used as signal light at 1550 nm, the light loss is minimal. In this way, if a proper concentration of germanium is incorporated into a suitable matrix, the amplifier can compensate for the loss in the communication system according to the laser principle. Therefore, in a telecommunications network that needs to amplify an optical signal with a wavelength of 1550 nm, the erbium-doped fiber amplifier must be indispensable. With few optics, current erbium-doped silica fiber amplifiers have been commercialized. It has been reported that in order to avoid useless absorption, the doping amount of germanium in the optical fiber is several tens to several hundreds of ppm. The rapid development of optical fiber communication will open up new fields of application.
(2) The additional erbium-doped laser crystal and its output of 1730nm laser and 1550nm laser are safe for human eyes, good atmospheric transmission performance, strong penetrating ability to the battlefield, good confidentiality, and difficult to be detected by the enemy. The military target has a large contrast ratio and has been made into a military-use portable laser range finder for human eyes.
(3) Er 3 + can be made into rare earth glass laser material by adding it to glass. It is the solid laser material with the highest output pulse energy and the highest output power.
(4) Er 3 + can also be used as an activated ion for rare earth up-conversion laser materials.
(5) The enamel can also be applied to the discoloration and coloration of spectacle glass and crystallized glass.
Yttrium oxide
Rare earth cerium oxide adds brilliance to glass
Helium laser and ultra-pulsed CO2 laser for oral clinical treatment
Erbium doped fiber amplifier
Cobalt-based alloy powders are commonly used in plasma transfer arc welding (PTAW) due to their excellent high-temperature properties and resistance to wear and corrosion. These alloys are typically composed of cobalt as the base metal, with various alloying elements such as chromium, tungsten, nickel, and carbon added to enhance specific properties.
The use of cobalt-based alloy powders in PTAW offers several advantages, including:
1. High-temperature strength: Cobalt-based alloys exhibit excellent strength and resistance to deformation at elevated temperatures, making them suitable for welding applications that involve high heat.
2. Wear resistance: These alloys have a high hardness and resistance to wear, making them ideal for welding applications where the welded parts are subjected to abrasive or erosive conditions.
3. Corrosion resistance: Cobalt-based alloys offer good resistance to corrosion, making them suitable for welding applications in aggressive environments, such as those involving chemicals or saltwater.
4. Thermal conductivity: Cobalt-based alloys have good thermal conductivity, allowing for efficient heat transfer during welding and reducing the risk of heat-affected zone (HAZ) defects.
5. Compatibility with other materials: Cobalt-based alloys can be easily welded to a wide range of base metals, including stainless steels, nickel alloys, and other cobalt-based alloys, providing versatility in welding applications.
To use cobalt-based alloy powders for PTAW, the powder is typically fed into the plasma arc using a powder feeder. The powder is then melted by the high-temperature plasma arc and deposited onto the workpiece, forming a weld bead. The specific welding parameters, such as arc current, travel speed, and powder feed rate, will depend on the specific alloy and application requirements.
It is important to note that the selection of the cobalt-based alloy powder should be based on the specific welding application and the desired properties of the final weld. Different cobalt-based a
Co Powder,Cobalt 6 Powder,Cobalt 12 Powder,Cobalt 21 Powder
Luoyang Golden Egret Geotools Co., Ltd , https://www.xtccarbide.com