Tungsten Carbide-Nickel Is Magnetic or Non-magnetic?
Tungsten Carbide-Nickel Is Magnetic or Non-magnetic?
Tungsten carbide, also called cemented carbide, is composed of tungsten carbide powder and binder powder. The binder powder can be cobalt powder or nickel powder. When we are using cobalt powder as a binder in manufacturing tungsten carbide products, we will have a cobalt magnetic test to inspect the amount of cobalt in the tungsten carbide. So it is surely that tungsten carbide-cobalt is magnetic. However, tungsten carbide-nickel is not magnetic.
You may feel it is unbelievable at the beginning. But it is true. Tungsten carbide-nickel is a kind of non-magnetic material with good impact resistance. In this article, I would like to explain this to you.
As purified metals, cobalt and nickel are magnetic. After mixing, pressing, and sintering with tungsten carbide powder, the tungsten carbide-cobalt is still magnetic, but the tungsten carbide-nickel is not. This is because the tungsten atoms enter the lattice of nickel and change the electron spins of nickel. Then the electron spins of the tungsten carbide can cancel out. So, the tungsten carbide-nickel can’t be attracted by a magnet. In our daily life, stainless steel also applies this principle.
What is electron spin? Electron spin is one of the three inherent properties of electrons. The other two properties are the mass and charge of the electron.
Most substances are composed of molecules, molecules are composed of atoms, and atoms are composed of nuclei and electrons. In the atoms, electrons are constantly spinning and rotating around the nucleus. These movements of electrons can create magnetism. In some substances, the electrons move in different directions, and the magnetic effects can cancel out so that these substances are not magnetic under normal circumstances.
However, some ferromagnetic substances such as iron, cobalt, nickel, or ferrite are different. Their electron spins can be arranged in a small range to form a magnetic domain. This is why purified cobalt and nickel are magnetic and can be attracted by a magnet.
In tungsten carbide-nickel, the tungsten atoms affect the electron spins of nickel, so tungsten carbide-nickel is not magnetic anymore.
According to many scientific results, tungsten carbide-nickel has higher corrosion resistance and oxidation resistance than tungsten carbide-cobalt. In sintering, the nickel can form a liquid phase easily, which can provide better wet ability on tungsten carbide surfaces. What’s more, nickel is lower in cost than cobalt.
If you are interested in tungsten carbide products and want more information and details, you can CONTACT US by phone or mail at the left, or SEND US MAIL at the bottom of the page.
