polycrystalline

Polycrystalline materials are made up of many small crystal blocks called grains, each with its own orderly atomic structure and different orientation. These grains fit together like a mosaic, giving the material overall strength and durability. Unlike single crystals, which have a uniform structure throughout, polycrystalline materials contain numerous grain boundaries where the crystals meet. This structure is common in metals and ceramics, affecting their mechanical properties, such as hardness and corrosion resistance. The size and arrangement of these grains influence how the material behaves under stress or heat, making polycrystalline structures important in engineering and manufacturing.