2.
Carbon graphite materials, graphite is composed of carbon element type of non-metallic materials.
It is one of the three kinds of carbon isomers, hexagonal system, each level consists of hexagonal ring, level and level parallel, overlapping in orderly crystal structure.
Graphite according to the source can be divided into natural graphite and artificial graphite two kinds.
Artificial graphite is composed of carbonaceous materials by the above 2500 ℃ high temperature graphitization treatment.
Carbon graphite generally good electrical conductivity, heat resistance, abrasion resistance, self-lubrication, high temperature stability, strong resistance to chemical corrosion, thermal conductivity is higher than the polymer, small linear expansion coefficient.
Under the condition of the atmosphere and room temperature with chrome plated surface friction coefficient and wear rate is very low.
But the loss of lubricity when humidity is low.
Coating wear-resisting coating can improve the wear resistance of carbon graphite.
Graphite not only as a solid lubricant, resin, metal, ceramics and other materials can be added, increase the friction of the material, also can be used directly as the friction pair material, such as paper making, woodworking, textile, food and other places of avoid oil bearing, high temperature sliding bearing, seal, piston ring, blade, etc.
Mechanical engineering with a 'class' of carbon graphite materials represent symbol for M, there are four series: carbon graphite materials, electrochemical graphite material, resin carbon composite and metal graphite material.
3.
Ceramic materials are inorganic non-metallic mineral natural or synthetic compounds as raw material, through crushing, shaping and high temperature sintering, and by the numerous inorganic non-metal small crystal and glass phase composition of the non-metallic materials.
In inorganic non-metallic natural minerals, such as clay, feldspar, quartz, etc as the raw material is made of traditional ceramic;
Synthetic compounds as raw material is made of special ceramics.
Mechanical engineering used in general is the aluminum oxide, magnesium oxide, zirconium oxide ceramics, lead oxide, titanium oxide, silicon carbide, boron carbide, silicon nitride, boron nitride etc. Artificial compound as a raw material production of special ceramics.
Ceramic to a large extent depends on the performance of their microstructure, including grain size and distribution, the composition and content of the glass phase, nature, content and distribution of impurities.
And microstructure are determined by the raw materials, components and manufacturing process.
Common characteristics of the ceramic is the hardness and high compressive strength, high temperature resistance, abrasion resistance, oxidation resistance, good corrosion resistance, very brittle, impact resistance and ductility.
Ceramic is a newer without lubrication bearing shell material, especially the SiC and Si3N4, their strength, heat resistance and corrosion resistance are good, tribology performance is very good also.
