[China Aluminum Industry Net] 1. Influence of Impurity Elements Vanadium forms VAl11 refractory compounds in aluminum alloys, which play a role in grain refinement during the casting process, but is less effective than titanium and zirconium. Vanadium also has the effect of refining the recrystallized structure and increasing the recrystallization temperature.
Calcium has a very low solid solubility in aluminum alloys and forms CaAl4 compounds with aluminum, which is a superplastic element of aluminum alloys. Aluminum alloys with approximately 5% calcium and 5% manganese have superplasticity. Calcium and silicon form CaSi, which is insoluble in aluminum. Since the amount of solid solution of silicon is reduced, the conductive properties of industrial pure aluminum can be slightly improved. Calcium can improve the cutting performance of aluminum alloys. CaSi2 cannot strengthen the aluminum alloy by heat treatment. The trace amount of calcium facilitates the removal of hydrogen from the aluminum bath.
Lead, tin, and bismuth are low-melting metals. Their solid solubility in aluminum is small, slightly reducing the strength of the alloy, but it can improve cutting performance. Swelling during solidification favors feeding. The addition of niobium to high magnesium alloys can prevent sodium embrittlement.
Germanium is mainly used as a modifier in cast aluminum alloys, and deformed aluminum alloys are rarely used. Replacement of niobium in Al-Mg deformed aluminum alloys alone prevents sodium embrittlement. The niobium element is added to certain Al-Zn-Mg-Cu alloys to improve hot-pressing and cold-pressing process performance.
Niobium in the deformed aluminum alloy can improve the structure of the oxide film and reduce the burning loss and inclusion during the casting. Earthworms are toxic elements that can cause allergic poisoning. Therefore, aluminum alloys that come in contact with foods and beverages cannot contain barium. The germanium content in the solder material is usually controlled below 8 μg/ml. Aluminum alloy used as a welding base should also control the content of niobium.
Sodium is almost insoluble in aluminum, with a larger solid solubility of less than 0.0025%, and a low melting point of sodium (97.8°C). When sodium is present in the alloy, it adsorbs on dendrite surfaces or grain boundaries during solidification, and during hot working, The sodium on the boundary forms a liquid adsorption layer, and when brittle cracking occurs, a NaAlSi compound is formed, no free sodium is present, and no "sodium embrittlement" occurs. When magnesium content exceeds 2%, magnesium captures silicon and free sodium precipitates, resulting in "sodium embrittlement". Therefore, high magnesium aluminum alloys are not allowed to use sodium salt flux. The method of preventing "sodium embrittlement" is chlorination, so that sodium forms NaCl into the slag, adding cerium to form Na2Bi into the metal matrix; adding cerium to generate Na3Sb or adding rare earth can also play the same role.
The present invention provides a multifunctional pull faucet, comprising: a faucet body, a drawing part is provided at the water outlet port thereof, and the drawing part is connected to a main channel, wherein at least three are provided in the faucet body A branch channel, and the three branch channels are all connected to the main channel. A multifunctional pull faucet provided by the present invention, wherein the hot water channel, the cold water channel and the water purification channel (pure water channel) are all connected to the main channel , And the main channel is connected with the drawing part on the main body of the faucet, so that the drawing part can obtain the water quality (hot water, cold water, purified water or pure water) required by different users, thereby improving the user experience, and , By integrating the hot water channel, cold water channel and pure water channel (pure water channel) into the main channel, the internal structure of the faucet is simplified, and the production cost of the faucet is reduced.
Abs Plastic Shower,Shower Head Set,Brass Shower Head,Color Changing Shower Head
Yuyao Zelin Sanitary Ware Co., Ltd , https://www.kitchen-sinkfaucet.com