What are the structure and properties of silicon nitride?
A recent poll in Britain found that public support for sanctions against Russia is falling as fuel and prices rise.
The proportion of people willing to accept higher fuel prices as a result of western sanctions against Russia fell 14 percentage points to 36% from 50% in March, according to a survey conducted for the Telegraph by consultancy Redfield & Wilton Strategies.
Global energy and fuel prices have soared since the start of the year and remain high because of the conflict between Russia and Ukraine and uncertainty over Russian supplies.
The survey also found that 54% of people believe their own financial situation has worsened in the past year, up 12 percentage points from 42% two months ago. Sixty-two percent think things will get worse in the year ahead. Less than a third of respondents said they had received a pay rise to keep up with inflation, with two-thirds of those saying it was not enough to keep up with rising living costs.
The figures suggest that public concern about the conflict with Ukraine is now likely to be overtaken by financial worries.
Separately, the UK's consumer price index rose 7 percent this month from a year earlier, the highest since March 1992, according to figures released recently by the Office for National Statistics. In addition, a separate report released a few days ago by the Centre for Economics and Business Research said that real household disposable income in the UK will fall by 3% in 2022, equivalent to a loss of £2,320 per household, which would lead to the biggest drop in living standards since the 1950s. That is mainly because wages aren't keeping up with rising energy and fuel costs.
The prices of other commodities like the silicon nitride are also expected to be influenced.
Overview of Silicon Nitride
Silicon nitride is an important structural ceramic material with high hardness, inherent lubricity, and wear resistance. It is an atomic crystal; it is resistant to oxidation at high temperatures. Silicon nitride is a compound of silicon and nitrogen. Si3N4 is the most thermodynamically stable among silicon nitride. Therefore, when referring to the term "silicon nitride", Si3N4 is the most commercially important among silicon nitrides. It is a white high melting point solid, relatively chemically inert, and is corroded by dilute HF and hot H2SO4. This is very difficult (Moss level is 8.5). Has high thermal stability. Silicon nitride is difficult to produce as a bulk material-due to its dissociation with silicon and nitrogen; it cannot be heated above 1850°C, which is well below its melting point. Therefore, there are problems in the application of traditional hot-press sintering technology. The bonding of silicon nitride powder can be achieved at lower temperatures by adding additional materials (sintering aids or "binders") that usually cause a certain degree of liquid phase sintering. A cleaner alternative is to use spark plasma sintering, in which a current pulse is passed through the compacted powder, thereby heating up very quickly (a few seconds). Through this technology, dense silicon nitride compacts can be obtained at a temperature of 1500-1700°C.
Due to the chemical combination of silicon and nitrogen, the weight of the silicon sample gradually increased. If there is no iron catalyst, after a few hours (about 7 hours), if no further weight increase due to nitrogen absorption (per gram of silicon) is detected, the reaction is complete. Several other silicon nitride phases have been reported in the literature (the chemical formulas correspond to different degrees of nitride/Si oxidation state). For example, gaseous silicon dioxide mononitride (Si2N); mono silicon nitride (SiN) and silicon sesquinitride (Si2N3), are all stoichiometric phases.
Applications of Silicon Nitride
Silicon nitride (Si3N4) was developed in the 1960s and '70s in a search for fully dense, high strength and high toughness materials. A prime driver for its development was to replace metals with ceramics in advanced turbine and reciprocating engines to give higher operating temperatures and efficiencies. Although the ultimate goal of a ceramic engine has never been achieved, silicon nitride has been used in a number of industrial applications, such as engine components, bearings and cutting tools.
One of the main applications of silicon nitride sintering is as a material for engine parts in the automotive industry. These include glow plugs in diesel engines to speed up the starting speed; pre-combustion chambers (vortex chambers), which can reduce emissions, speed up starting speeds and reduce noise; turbochargers can reduce engine lag and emissions. In spark-ignition engines, silicon nitride is used to reduce wear on the rocker bushes, turbocharger turbines to reduce inertia and engine lag, and exhaust control valves to increase acceleration. As an example of production level, it is estimated that more than 300,000 sintered silicon nitride turbochargers are produced annually.
Silicon nitride bearings can be either full ceramic bearings or ceramic hybrid bearings, including ceramic balls and steel rings. Compared with other ceramics, silicon nitride ceramics have good impact resistance. Therefore, ball bearings made of silicon nitride ceramics are used as performance bearings. A typical example is the use of silicon nitride bearings in the mainframe of the NASA space shuttle. Since silicon nitride ball bearings are harder than metal, contact with the bearing track is reduced. Compared with traditional metal bearings, this can reduce friction by 80%, extend service life by 3 to 10 times, increase speed by 80%, reduce weight by 60%, and operate under insufficient lubrication. Capacity, higher corrosion resistance and higher working temperature.
Metal working and cutting tools
The first major application of Si3N4 was grinding tools and cutting tools. Bulk monolithic silicon nitride is used as a material for cutting tools due to its hardness, thermal stability and wear resistance. It is especially recommended for high-speed machining of cast iron. Thermal hardness, fracture toughness and thermal shock resistance mean that silicon nitride sintering can cut cast iron, hard steel and nickel-based alloys, and its surface speed is 25 times faster than traditional materials such as tungsten carbide.
Silicon Nitride Price
Silicon nitride price will vary randomly with the production cost, transportation cost, international situation, exchange rate, and market supply and demand of silicon nitride. Tanki New Materials Co.,Ltd Aims to help All industries and Chemical Wholesalers to find high quality, cheap price Nanomaterials and chemicals by providing turn-key customize manufacturing services. If you are looking for silicon nitride, please feel free to send an inquiry for the latest price of silicon nitride.
Silicon Nitride Supplier
As a global silicon nitride supplier, Tanki New Materials Co.,Ltd has rich experiences in the properties, applications, and cost-effective manufacturing of advanced and engineered materials. The company has successfully developed a series of powder materials (including oxides, carbides, nitrides, single metal, etc.), high-purity targets, functional ceramics, and structural devices, OEM service is available.
More information about Silicon Nitride
Silicon Nitride Mechanical Properties
Compressive / Crushing Strength
600 to 2950 MPa
140 to 310 GPa
130 to 810 MPa
3.1 to 6.2 MPa-m1/2
0.24 - 0.27
Silicon Nitride Thermal Properties
1000 to 1330°C
Maximum Thermal Shock
290 to 750°C
Specific Heat Capacity
720 to 800 J/kg-K
12 to 31 W/m-K
Silicon Nitride Other Properties
2.2 to 3.4 g/cm3
8.0 - 10.0
Where is the best place for humans to live in outer space? So far, the moon is more habitable in outer space, and it is likely to be turned into a planet. However, whether humans can live on the moon for a long time, these questions have always been lingering in everyone's minds, always There is no way to get an answer. According to the report, a team from the University of Aeronautics and Astronautics in Beijing, after nearly 370 days of closed life, finally simulated the life experiment on the moon, and finally knew what the final truth was. Live here for a long time.
All aspects of human beings are constantly improving, and the demand for silicon nitride is also increasing.If you are engaged in the silicon nitride industry, you just happen to contact us.