Generally, flint alloy is made, and mixed rare earth metals are widely used, among which cerium is the main one. It contains light rare earth elements such as lanthanum, praseodymium and neodymium. Rare earth metals are active in chemistry and have strong affinity for oxygen, while the ignition temperature of cerium group metals is very low (165℃ for cerium, 290℃ for praseodymium and 270℃ for neodymium), and a lot of heat is released during combustion.

The chemical composition of flint is closely related to its structure and ignition performance.

1, rare earth metal rare earth element is the matrix and main component of flint alloy. It has great affinity with oxygen and gives off a lot of heat when it reacts.

2. Iron is the main filler in the alloy, which can improve the hardness of the alloy and react with rare earth cerium to produce CeFe. Cefe: intermetallic compound with Fe content below 12% has good cutting performance and poor ignition performance, but with Fe content above 25%, it has high hardness, large extrusion force and poor forming.

3. Magnesium can form CeMg intermediate compound with rare earth cerium, which has low ignition point and enhanced ignition performance. When the magnesium content is higher than 5%, the ignition performance is good, but the extrusion force is high; The magnesium content is too low, the luminescent performance is poor, and the grains in the alloy are refined, which makes the alloy tough and can not be pulverized when rubbed. Fire is not a spark, but a flame

4. Zinc in zinc alloy does not contribute to flammability, but it can increase the density and corrosion resistance of the alloy. So the composition of zinc should not be high.

5. Copper Adding a small amount of copper to the alloy has no adverse effect on the ignition performance, wear resistance and storage stability of flint, but it is effective in reducing pressure, but the composition of copper should not be too high.

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Generally, friction on lighters causes sparks to ignite, and there are also special flints to ignite, which is slightly different. The flint composition of lighter is mainly cerium-iron alloy composed of cerium and lanthanum.

Both cerium and lanthanum are flammable metals, and the alloy made of iron is hard and brittle, and Mars will appear when it hits. When this flint is rubbed by an iron wheel with a toothed edge, dust will fall off, splashing sparks and sparks. The main component of flint is silicon dioxide, which is very hard and exceeds that of iron.

When the two phases collide, iron filings will splash to the surface of the fire sickle. Due to the friction and heat generated by the impact, these iron filings have a high temperature and react with oxygen in the air, giving off bright light and generating a gray oxide-ferroferric oxide. Mixed rare earth metal powder is easy to catch fire. When flint made of ferroalloy is rubbed with an iron wheel with toothed edge, powder scraps will fall off and sparks will be splashed.

Zippo flint contains cerium 45-5 1%, lanthanum 23-26%, neodymium 15- 19%, praseodymium 4-6%, other rare earth 1-2% and iron < 3%.

In ancient times, it was a tool to ignite with fire sickle and tinder. It is a kind of stone, usually called flint. Most of them are produced in mountains, and some of them are produced in water, which can be ignited.

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