Green silicon carbide fraction for SiC advanced ceramics
The raw material of sintered silicon carbide ceramics is a high-purity silicon carbide fraction with a content of 98-99%. In most cases, SiC advanced ceramic manufacturers adopt black silicon carbide particles and black silicon carbide powder. Those SiC ceramics are SiC ceramic pump, nozzles, wear-resistant plates,sealing rings and other products. In recent years, the demand for silicon carbide ceramics developed in the new energy vehicle industry. Silicon carbide ceramics in the field of lithium batteries have new development prospects. This also puts forward higher requirements for silicon carbide ceramic raw materials. Green silicon carbide gets higher SiC purity and hardness than those black silicon carbide. The chemical stability and thermodynamic performance are also better than the black color. Therefore, for silicon carbide ceramics in new energy-related industries, green silicon carbide with a purity of more than 99% is more suitable.
Since the 1960s, silicon carbide began to work as raw material for high-performance silicon carbide composite ceramics. Silicon carbide ceramics are widely used in fine chemicals, semiconductors, metallurgy, national defense and military industries. SiC advanced ceramics get features of wear resistance, high mechanical strength, low density, and specific gravity, stable chemical and thermodynamic properties, high thermal conductivity, and low thermal expansion coefficient.
In recent years, lithium batteries developed because of new energy vehicles. Silicon carbide ceramics also play an important role in the preparation of its raw materials.
1. Fine grinding of lithium iron phosphate
At present, lithium iron phosphate is widely used as the cathode material of lithium batteries. The “ultra-fine grinding” of lithium iron phosphate needs to maintain the stability of the grinding equipment during high current discharge. This is also one of the main means to improve its performance.
At present, the most commonly used equipment in this process is milling. Silicon carbide ceramic lining in the milling machine can make milling more suitable for the production of lithium iron phosphate. For example, the silicon carbide inner cylinder has high hardness, wear resistance, and good thermal conductivity. It can quickly take away the heat in the grinding chamber, greatly improve the grinding efficiency and reduce energy consumption.
2. High-temperature sintering of ternary materials
Positive electrode materials are generally prepared by reaction of oxide raw materials or precursors at higher temperatures. Crucibles are prone to cracking and peeling during rapid heating and cooling. Therefore, vessels with high-temperature resistance and good thermal shock resistance are required to contain oxide raw materials or precursor materials.
The high-temperature resistance, corrosion resistance, and high load-bearing properties of silicon carbide ceramics are just suitable for the high-temperature sintering process of ternary materials. It ensures the stability and reliability of high-temperature calcination.
3. Photovoltaic field
Silicon carbide ceramics are well applicated in the photovoltaic field. For example, in the synthesis process of monocrystalline silicon and polycrystalline silicon, the impact resistance, wear resistance and high-temperature resistance of silicon carbide ceramics and the high purity of surface chemical vapor deposition ensure the synthesis process of silicon materials. In the heat treatment and oxidation process of silicon wafers, silicon carbide ceramics have a high-temperature bearing capacity and high purity. It can improve the processing temperature of the process and thus improve the performance of silicon wafers. Therefore, core components such as crystal boats, brackets, and cantilever paddles are increasingly becoming important kiln furniture components.
At present, silicon carbide kiln furniture manufacturers always adopt green silicon carbide fractions F90, F150, F180, and green silicon carbide powder F240 F2000 microns.
