What does metal include?

2. There are several classification methods for metals: Metallurgical industry classification method: Ferrous metals: iron, chromium, manganese Three non-ferrous metals: aluminum, magnesium, potassium, sodium, calcium, strontium, barium, copper, lead, zinc, tin, cobalt

, nickel, antimony, mercury, cadmium, bismuth, gold, silver, platinum, ruthenium, rhodium, palladium, osmium, iridium, beryllium, lithium, rubidium, cesium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, tungsten, molybdenum

, gallium, indium, thallium, germanium, rhenium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, thorium.

Metals can also be divided into: Neodymium metal Common metals: such as iron, aluminum, copper, zinc, etc. Rare metals: such as zirconium, hafnium, niobium, tantalum, etc.; 1. Light metals.

The density is less than 4500 kg/cubic meter, such as aluminum, magnesium, potassium, sodium, calcium, strontium, barium, etc.

2. Heavy metals.

Density greater than 4500 kg/m3, such as copper, nickel, cobalt, lead, zinc, tin, antimony, bismuth, cadmium, mercury, etc.

3. Precious metals.

It is more expensive than commonly used metals, has low abundance in the earth's crust, and is difficult to purify, such as gold, silver and platinum group metals.

4. Metalloid elements.

The nature and value are between metals and non-metals, such as silicon, selenium, tellurium, arsenic, boron, etc.

5. Rare metals.

Including rare light metals, such as lithium, rubidium, cesium, etc.; 6. Rare refractory metals, such as titanium, zirconium, molybdenum, tungsten, etc.; 7. Rare dispersed metals, such as gallium, indium, germanium, thallium, etc.; 8. Rare earth metals,

Such as scandium, yttrium, lanthanide series metals; 9. Radioactive metals, such as radium, francium, polonium and uranium, thorium, etc. in the Al series elements.

What material is metal? It is a general term for metal elements or materials with metallic properties that are mainly composed of metal elements.

Including pure metals, alloys, metallic materials, intermetallic compounds and special metal materials, etc.

(Note: Metal oxides (such as alumina) are not metallic materials) Significance: The development of human civilization and the progress of society are closely related to metallic materials.

The Bronze Age and Iron Age that followed the Stone Age were marked by the application of metal materials.

In modern times, a wide variety of metal materials have become an important material basis for the development of human society.

Type: Metal materials are usually divided into ferrous metals, non-ferrous metals and special metal materials.

① Ferrous metals are also called steel materials, including industrial pure iron containing more than 90% iron, cast iron containing 2% to 4% carbon, carbon steel containing less than 2% carbon, and structural steel, stainless steel, and heat-resistant steel for various purposes.

Steel, high temperature alloy stainless steel, precision alloy, etc.

Generalized ferrous metals also include chromium, manganese and their alloys.

② Non-ferrous metals refer to all metals and their alloys except iron, chromium and manganese, which are usually divided into light metals, heavy metals, precious metals, semi-metals, rare metals and rare earth metals.

The strength and hardness of non-ferrous alloys are generally higher than those of pure metals, and they have higher resistance and smaller temperature coefficient of resistance.

③Special metal materials include structural metal materials and functional metal materials for different uses.

Among them are amorphous metal materials obtained through rapid condensation processes, as well as quasicrystalline, microcrystalline, nanocrystalline metal materials, etc.; there are also special functional alloys such as stealth, hydrogen resistance, superconductivity, shape memory, wear resistance, vibration reduction and damping, etc.

, and metal matrix composite materials, etc.

Performance: Generally divided into two categories: process performance and usage performance.

The so-called process performance refers to the performance of metal materials under specified cold and hot processing conditions during the manufacturing process of mechanical parts.

The quality of the process performance of metal materials determines its adaptability to processing and forming during the manufacturing process.

Due to different processing conditions, the required process properties are also different, such as casting performance, weldability, forgeability, heat treatment performance, cutting processability, etc.

The so-called performance refers to the performance of metal materials under the conditions of use of mechanical parts, which includes mechanical properties, physical properties, chemical properties, etc.

The performance of metal materials determines its range of use and service life.

In the machinery manufacturing industry, general mechanical parts are used in normal temperatures, normal pressures and very corrosive media, and each mechanical part will bear different loads during use.

The ability of metal materials to resist damage under load is called mechanical properties (it was also called mechanical properties in the past).

The mechanical properties of metal materials are the main basis for the design and material selection of parts.

Depending on the nature of the external load (such as tension, compression, torsion, impact, cyclic load, etc.), the mechanical properties required for metal materials will also be different.

Commonly used mechanical properties include: strength, plasticity, hardness, impact toughness, multiple impact resistance and fatigue limit.

What is metal?

This type of substance has unique luster and opaqueness (the result of strong reflection of visible light), and is rich in malleability, ductility, thermal conductivity, and electrical conductivity.

Extension: 1. The most ductile among metals is Au, and the best conductors are Ag, Cu, Au, and Al; 2. There are several classification methods for metals: Metallurgical industry classification: Ferrous metals: iron, chromium, and manganese

Non-ferrous metals: all metals except iron, chromium and manganese.