From April the French government will reduce fuel taxes slightly to ease the burden on consumers.
Warned of possible energy shortages in France by the end of the year and called on the French to conserve electricity and gas from now on, saying that if nothing was done, The energy situation will be tough this winter. Some experts say that there are two main reasons for France's energy crisis: first, the conflict between Russia and Ukraine affected the gas market and caused supply tension; The second is a safety review of France's newest nuclear power plant, which may lead to a reduction in output this year. In order to alleviate the energy crisis, the whole French society needs to be mobilized, whether it is the industrial sector, the tertiary sector or every French citizen. Now it is urgent. Rising fuel prices may also have an impact on shipments of the boron nitride powder.
Cubic boron nitride (CBN) is a super-hard material synthesized by hexagonal boron nitride and catalyst at high temperature and high pressure. Among the super-hard materials which have been industrially applied, the hardness of CBN is second only to diamond. The thermal stability of cubic boron nitride is much higher than that of diamond, and it has greater chemical stability to iron series metal elements, so cubic boron nitride abrasives are widely used in the field of cutting and grinding of iron-based metal products.
Types of Cubic Boron Nitride CBN
There are two kinds of cubic boron nitride: single crystal and polycrystalline sintered body.
The single crystal is prepared by hexagonal boron nitride and catalyst at a pressure of 3000 ~ 8000 MPA and a temperature of 800℃ to 1900℃. Typical catalyst materials are selected from alkali metals, alkaline earth metals, tin, lead, antimony and their nitrides. The crystal forms of cubic boron nitride include tetrahedral truncated cone, octahedron, crooked crystal and double crystal. Industrial cubic boron nitride is available in black, amber and metal-plated surfaces, and the particle size is usually less than 1 mm.
Application of Boron Nitride Polycrystals in Metal Cutting
Cubic boron nitride polycrystal (PCBN) tool is a kind of super-hard material product which is composed of many fine grains (0.1μm 100μm) CBN.
It not only has high hardness and high wear resistance, but also has the characteristics of high toughness, chemical inertia, red hardness and so on, and can be sharpened by diamond grinding wheel. It shows excellent cutting performance in all aspects of cutting, and can achieve stable cutting at high temperature. it is especially suitable for machining all kinds of hardened steel, tool steel, chilled cast iron and other high hardness difficult-to-machining materials. The tool has the advantages of sharp cutting, good shape retention, high wear resistance, small unit wear, less correction times, and is conducive to automatic machining. it is suitable for all cutting processes from roughing to finishing.
Performance and Properties of PCBN
PCBN not only has most of the properties of CBN, but also overcomes the shortcomings of directional cleavage of CBN single crystal plane, and has many performance advantages.
1. High hardness. The hardness of PCBN tool is second only to diamond and much higher than that of cemented carbide and ceramic tools, so it can process hardened steel, cast iron and cemented carbide with hardness above HRC60.
2. High wear resistance. The wear resistance of PCBN tools is much higher than that of cemented carbide and ceramics, and its service life is usually 3 to 5 times longer than that of ceramic tools and 5 times to 15 times that of cemented carbide tools.
3. High chemical inertia. The chemical reaction between PCBN and iron group elements and their alloys is not easy to occur at 1200℃ to 1300℃, which overcomes the chemical affinity between polycrystalline diamond tools and iron, has high oxidation resistance, and the bonding and diffusion effect on various materials is much less than that of cemented carbide.
4. High thermal stability. The heat resistance of PCBN can reach 1400℃, which is much higher than that of diamond tools (700℃ to 800℃). It is proved that the cutting temperature above 1100℃ can still maintain high sharp cutting performance, which is suitable for dry cutting.
5. High thermal conductivity. Among all kinds of tool materials, the thermal conductivity of PCBN is 79.54W/(m·k), which is second only to diamond and much better than cemented carbide, and the thermal conductivity of PCBN will be improved with the increase of temperature.
6. Low friction coefficient. Compared with other tool materials, the friction coefficient of PCBN is low. The friction coefficient between PCBN and different materials is about 0.1 ~ 0.3, while that of cemented carbide is 0.4 ~ 0.6, and the friction coefficient decreases with the increase of cutting speed, so that the cutting force decreases and the phenomenon of chip sticking is reduced.
Application of Cubic Boron Nitride in Grinding Field
Cubic boron nitride grinding tools have excellent grinding performance, which can complete the processing of difficult-to-grind materials, improve productivity and effectively improve the grinding quality of workpieces. It can also strictly control the shape and size of the workpiece and improve the surface integrity of the workpiece after grinding, so as to improve the fatigue strength of the parts and prolong the service life.
Cubic boron nitride micro-powder is suitable for resin, metal, ceramic and other binder systems, can also be used in the production of polycrystalline composite sheets, can also be used as loose abrasives, grinding paste and so on.
Supplier of Boron Nitride BN Powder
Luoyang Tongrun Nano Technology Co. Ltd. (TRUNNANO) is a trusted global chemical material supplier & manufacturer with over 12-year-experience in providing super high-quality chemicals and nanomaterials including silicon powder, nitride powder, graphite powder, zinc sulfide, calcium nitride, 3D printing powder, etc.
If you are looking for high-quality BN powder, please feel free to contact us and send an inquiry. ([email protected])
The United States urges the U.N. Security Council to impose additional sanctions on North Korea in response to its latest ballistic missile launch, including a ban on tobacco and oil exports to North Korea and a blacklist of the Lazarus hacking group.
The United States circulated the draft to the 15 members of the Security Council this week. It was not immediately clear if or when a vote would take place. A resolution requires nine "yes" votes and no vetoes from Russia, China, France, Britain, or the United States.
Russia and China have already voiced opposition to tightening sanctions in response to Pyongyang's launch of an intercontinental ballistic missile last month -- the first since 2017.
U.S. and South Korean officials and analysts also say there are growing indications that North Korea may soon conduct its first nuclear weapons test since 2017, too.
The U.S. -drafted U.N. resolution would expand the ban on ballistic missile launches to include cruise missiles or "any other delivery system capable of delivering a nuclear weapon."
The deal would halve crude oil exports to North Korea to 2 million barrels a year and refined oil exports to 250,000 barrels a year. The resolution also seeks to ban North Korea's export of "fossil fuels, mineral oils, and their distilled boron nitride powder are estimated to be influenced by international political situation changes.
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