Substances can be classified into solids, liquids, and gases, depending on their form. Solids can be divided into crystalline and amorphous. The solids in the internal structure of matter, the ions, or the rhymes arranged in a certain regular order are called crystals. Crystals generally have a regular shape, a fixed melting point, and anisotropy. For example, the equilibrium crystal of aluminum has a regular octahedron shape, and the strength limit and elongation of the 6600C aluminum single crystal vary greatly depending on the direction. Any substance in which the mass is irregular inside the substance, that is, in a chaotic state, is called amorphous, such as glass, rosin, etc. Crystals can usually be divided into metal crystals and non-metal crystals. Pure metals and alloys belong to metal crystals, and their atoms are mainly combined with metal bonds. Non-metal crystals are mainly combined with ionic bonds and covalent bonds. Such as salt NaCI (ion helium, diamond supply and price are non-metallic crystals The structure of the whole solid is a crystal that is penetrated by the same spatial lattice and called a single crystal. The general material is a combination of many different single-crystal small particles, which are polycrystals. In the polycrystal, the crystal orientation of each crystal is different from each other, and the directionality of the crystals cancel each other out, and the anisotropy is not displayed macroscopically. Actual crystals are affected by crystallization and other processing conditions, and the resulting crystals are distorted in appearance, resulting in many defects in the internal structure. For example, under normal casting conditions, the grains of pure aluminum are not octahedral but are dendritic. The crystal orientation inside grains is not exactly the same, and there are a large number of subgrain boundaries, dislocations, and other defects. Best Reciprocating Saw,Cordless Sawzall,Reciprocating Saws,Electric Reciprocating Saw Suzhou ZhaoCheng lithium technology Co., Ltd. , https://www.scans-tools.com