Metal materials are usually divided into black metal, non-ferrous metal and special metal materials.
① Ferrous metal, also known as iron and steel materials, includes industrial pure iron with total impurity content<0.2% and carbon content not exceeding 0.0218%, steel with carbon content of 0.0218%~2.11%, cast iron with carbon content greater than 2.11%. Ferrous metals in a broad sense also include chromium, manganese and their alloys.
② Non-ferrous metals refer to all metals and their alloys except iron, chromium and manganese, usually divided into light metals, heavy metals, precious metals, semi-metals, rare metals and rare earth metals, etc. The strength and hardness of non-ferrous alloys are generally higher than that of pure metals, and the resistance is large and the resistance temperature coefficient is small.
③ Special metal materials include different uses of structural metal materials and functional metal materials. Among them, amorphous metal materials, quasicrystalline, microcrystalline and nanocrystalline metal materials are obtained by rapid condensation process. There are also special functional alloys such as stealth, hydrogen resistance, superconductivity, shape memory, wear resistance, vibration damping and metal matrix composite materials.