In recent years, with the continuous development of cutting workpiece materials, especially the emergence of some difficult-to-machine materials, super-hard material tools have been more and more widely used. The number, scale and manufacturing level of domestic super-hard material tool manufacturers are all It is improving rapidly. The superhard materials and products exhibition area of ​​the 2011 China (Zhengzhou) International Abrasives Grinding Exhibition held on November 11-13, Henan Fenike, Zhengzhou Bote, Zhengzhou Sanmao, Zhengzhou Diamond, Zhongnan Diamond, Zhengzhou Dozens of superhard materials and tool manufacturers, such as Huajing, have shown the rapid development and tremendous progress of domestic superhard materials to the audience.
In the current tool market, the tool materials occupying the largest market share are still high-speed steel and hard alloy, but the hardness of these tools is only 2000-3000HV. If the bonding material is added, the overall hardness is below 2000HV. For difficult materials and high speed and high precision machining, lower hardness tool materials are no longer suitable. Ultra-hard material tools represented by diamond and cubic boron nitride (CBN) quickly occupied this market. Among them, diamond has extremely high hardness and wear resistance, and its hardness can reach 10000HV, which is the hardest in tool materials, and its thermal stability can reach 700°C～800°C. Cubic boron nitride is second only to diamond (up to 8000 HV to 9000 HV) and has higher thermal stability (up to 1250 ° C to 1350 ° C).
In the interview, the reporter learned that superhard material tools have the characteristics of high processing efficiency, long service life and good processing quality. In the past, they were mainly used for finishing. In recent years, due to the improvement of the production process of artificial superhard tool materials, the control has been carried out. Raw material purity and grain size, using composite materials and hot pressing process, the application range is expanding, in addition to general finishing and semi-finishing, it can also be used for roughing, which is recognized internationally as a productivity increase. One of the most promising tool materials. Using ultra-hard materials to process steel, cast iron, non-ferrous metals and their alloys, cutting speed can be an order of magnitude higher than that of hard alloys, and tool life can be tens or even hundreds of times higher than that of hard alloys. At the same time, its appearance also changes the traditional process concept. With super-hard tools, it can often be directly milled or milled (or polished). For hardened parts processing, a single process can be used instead of multiple processes, which greatly shortens the process. .
Zhang Taihe, chief engineer of Henan Fenike Superhard Materials Co., Ltd., told the reporter that the diamond material cutter has extremely high hardness and wear resistance, and can effectively process non-ferrous metals such as copper and aluminum, alloys thereof, ceramics, and hard sintered. Alloys, various fiber and particle reinforced composites, etc. Compared with diamond, cubic boron nitride has higher thermal stability, strong chemical inertness to iron group elements, strong anti-bonding ability, and is more suitable for processing various hardened steels, thermal spray materials, chilled cast iron and HRC35. Hard-to-cut materials such as cobalt-based and nickel-based.
Nowadays, the advantages of super-hard material cutting tools in cutting processing have been well known by users, and have been more and more widely recognized and applied, and the market demand is huge. From the perspective of superhard materials, China has obvious resource advantages. Diamond production accounts for more than 80% of the world's total output. Cubic boron nitride (CBN) production accounts for more than 60% of the world's total output. It is already the world's largest super. In the hard material producing countries, China has entered the ranks of world powers in terms of superhard materials. China's superhard materials industry has taken the lead in becoming one of the industries with international voice. However, in fact, the domestic super-hard material tools are still in the initial stage of development and growth. Some enterprises are working hard toward high-end, precision super-hard material tools, and have achieved many achievements, but still can not meet the growing market demand. In the future tool market, super-hard material tools will occupy a more important market position.
Potassium Carbonate, Potassium Bicarbonate and Magnesium Carbonate can be used as pH regulator, nutrient, food additive, pharmaceutical ingridient, yeast, baking powder, swelling agent, additive for beverage, infant formula powder etc.
Sodium carbonate ("soda" or "natron") and potassium carbonate ("potash") have been used since antiquity for cleaning and preservation, as well as for the manufacture of glass. Carbonates are widely used in industry, e.g. in iron smelting, as a raw material for Portland cement and lime manufacture, in the composition of ceramic glazes, in food additive and beverage ingredients, in pharmaceutical raw materials etc..
In aqueous solution, carbonate, bicarbonate, carbon dioxide, and carbonic acid exist together in a dynamic equilibrium. In strongly basic conditions, the carbonate ion predominates, while in weakly basic conditions, the bicarbonate ion is prevalent. In more acid conditions, aqueous carbon dioxide, CO2(aq), is the main form, which, with water, H2O, is in equilibrium with carbonic acid – the equilibrium lies strongly towards carbon dioxide. Thus sodium carbonate is basic, sodium bicarbonate is weakly basic, while carbon dioxide itself is a weak acid.
Carbonated water is formed by dissolving CO2 in water under pressure. When the partial pressure of CO2 is reduced, for example when a can of soda is opened, the equilibrium for each of the forms of carbonate (carbonate, bicarbonate, carbon dioxide, and carbonic acid) shifts until the concentration of CO2 in the solution is equal to the solubility of CO2 at that temperature and pressure. In living systems an enzyme, carbonic anhydrase, speeds the interconversion of CO2 and carbonic acid.
Although the carbonate salts of most metals are insoluble in water, the same is not true of the bicarbonate salts. In solution this equilibrium between carbonate, bicarbonate, carbon dioxide and carbonic acid changes consonant to changing temperature and pressure conditions. In the case of metal ions with insoluble carbonates, e.g. CaCO3, formation of insoluble compounds results. This is an explanation for the buildup of scale inside pipes caused by hard water.
Potassium carbonate (K2CO3) is a white salt, which is soluble in water (insoluble in ethanol)[2] and forms a strongly alkaline solution. It can be made as the product of potassium hydroxide's absorbent reaction with carbon dioxide. It is deliquescent, often appearing a damp or wet solid. Potassium carbonate is used in the production of soap and glass.
potassium carbonate is prepared commercially by the electrolysis of Potassium Chloride. The resulting potassium hydroxide is then carbonated using carbon dioxide to form potassium carbonate, which is often used to produce other Potassium compounds.
Potassium carbonate was historically for soap, glass, and china production.
in cuisine, where it has many traditional uses. It is an ingredient in the production of grass jelly, a food consumed in Chinese and Southeast Asian cuisines, as well as Chinese noodles and moon cake. It is used to tenderize tripe. German gingerbread recipes often use potassium carbonate as a baking agent.
in the production of cocoa powder to balance the pH (i.e., reduce the acidity) of natural cocoa beans; it also enhances aroma.
as a Buffering Agent in the production of mead or wine.
in antique documents, it is reported to have been used to soften hard water.
as a fire suppressant in extinguishing deep-fat fryers and various other B class-related fires.
in condensed aerosol fire suppression, although as the byproduct of potassium nitrate.
as an ingredient in welding fluxes, and in the flux coating on arc-welding rods.
as an animal feed ingredient to satisfy the potassium requirements of farmed animals such as broiler breeders.
Carbonate
Food Grade Potassium Bicarbonate,Potassium Carbonate Food Grade,Dipotassium Carbonate,Potassium Carbonate
Jiangsu Kolod Food Ingredients Co., Ltd. , http://www.kolodchem.com