Development history and application of alloys

China is one of the earliest countries in the world to study and produce alloys, and bronze (copper-tin alloy) technology was very developed in Shang Dynasty (more than 3000 years ago). Around the 6th century BC (late Spring and Autumn Period), sharp swords (steel products) have been forged (and overheated). The bronze sword of Gou Jian, King of Yue, is an alloy sword that has been vulcanized. It is extremely sharp after being unearthed.

Steel is an alloy of iron with carbon, silicon, manganese, phosphorus, sulfur and a small amount of other elements. Except Fe, the content of C plays a major role in the mechanical properties of steel, so it is collectively called iron-carbon alloy. It is the most important and commonly used metal material in engineering technology. With the increase of carbon content, the hardness of carbon steel increases and the toughness decreases. Alloy steel is also called special steel. Adding one or more alloying elements on the basis of carbon steel changes the structure and properties of steel, thus having some special properties, such as high hardness, high wear resistance, high toughness and corrosion resistance. The alloying elements often added in steel are silicon, tungsten, manganese, chromium, nickel, molybdenum, vanadium, titanium and so on.

High-strength aluminum alloys are widely used to manufacture airplanes, ships and trucks, which can increase their load capacity and speed, and have the characteristics of seawater corrosion resistance and magnetic avoidance.

The main additive elements of zinc alloy are aluminum, copper and magnesium. Zinc alloy can be divided into deformed zinc alloy and cast zinc alloy according to processing technology. The cast zinc alloy has good fluidity and corrosion resistance, and is suitable for die-casting instruments, automobile parts shells and so on.

Lead-tin alloys (including lead-tin alloys and lead-free tin alloys) can be used to make various exquisite alloy ornaments and alloy handicrafts, such as rings, necklaces, bracelets, earrings, brooches, buttons, tie clips, hats, craft ornaments, alloy photo frames, religious emblems, miniature statues, souvenirs, etc.

Titanium alloy has been widely used in various sectors of the national economy and is an indispensable material for rockets, missiles and space shuttles. Titanium alloys are widely used in ships, chemicals, electronic devices and communication equipment, as well as some light industries. However, the high price of titanium at present limits its wide use.

Magnetic alloys are widely used in emerging technical fields such as electric power, electronics, computers, automatic control and optoelectronics.