The most difficult to melt metal

In all types of metals, tungsten is the most difficult to melt, the most volatile of the metals is not easy, so called "high melting point metal", and its melting point as high as 3380 degrees, the boiling point is 5927 degrees.

Tungsten Latin means "wolf's mouth foam", tungsten how it linked with the predators? In fact, in a long time ago, people discovered tin ore smelting, when the ore contains a brown witherite, the tin will be a sharp decline in production. This is like the original witherite wolf will devour the sheep eat the same tin. Therefore, the tungsten has been called "the wolf's mouth foam."

Tungsten in the earth's crust about one hundred thousandth. Nature black manganese tungsten iron ore (also known as wolframite) and yellow gray calcium tungsten ore (also known as scheelite), tungsten ore reserves in China account for the world. Nanling our country is the world's richest scheelite zone, especially in the southern Jiangxi Province, known as "Metal Township." Jiangxi and Hunan dayu Shizhuyuan have the world's largest tungsten mine.

As early as the 18th century, humans have discovered the tungsten, but it was only in 1850 obtained by the Wheeler pure tungsten metal. But since then it has been widely used. Except for its filament, but also used for high-performance cutting tool.

In 1864, the British people the first time Frechette steel add 5% of tungsten, Make a change to maintain high hardness of the alloy. Tool steel to do this can speed metal from the original 5 meters per minute, increased to 7.5 meters per minute. Developed as a result of constant volume with different high-speed tungsten steel, so that gradually increase speed. After 40 years, the metal tungsten steel cutting speed to 35 meters per minute, so cutting capacity by 6 times.

In 1907, a tungsten, chromium and cobalt-based alloy - "Staley," The successful development of cemented carbide, higher cutting speed is more to create the conditions.

Ultra-modern carbide is tungsten carbide and a number of other elements of the carbide produced by sintering method. It is the refractory metals (tungsten, tantalum, titanium, molybdenum, etc.) of the hard carbide particles, with one or more of the iron group elements (cobalt, nickel or iron) to suppress the powder mixture of shape, then sintered made.

Carbide is the world's highest strength alloy. Carbide is now widely used there are two main categories: first, the binder is made of cobalt-based alloy of tungsten carbide; second type of binder is made of tool steel titanium carbide-based alloys.

Cemented carbide cutting tools used to do, and its degree of hardness, even in 1000 under the high temperature will not be compromised. Therefore, high-speed machining, cutting speed to reach 2000 meters per minute or more, than ordinary carbon steel knives more than 100 times higher than that of tungsten steel cutting tool 15 times higher. Mold made of it, you can press more than 300 million times durable than regular steel die 60 times.