1. Composition
The main components of the blade are tungsten carbide and cobalt with different proportions. The primary form of the raw material is powder. The container is filled with the prepared raw materials, which will be used to produce different powders. Each container weighs about 560 kg.
2. Proportion
In the workshop, the dry raw materials are mixed with the solvent made of ethanol and water to form a kind of grey paste with viscosity similar to yogurt.
3. Open the mold
After the slurry is dried, the samples are sent to the laboratory for quality testing. These powders are composed of many particles with diameters ranging from 200 to 20 microns. They are very tiny (a hair is 50 to 60 microns thick).
4. Suppression
The powder is carried in a 100 kg barrel to the side of the press used to make the blades. The operator put the die (used for stamping different blades) into the machine tool and input the order number into the computer. The cavity of the die is filled with powder. The pressure of stamping each blade is up to 12 tons. The machine will weigh each blade and the operator will observe and control it. At this stage, the blade is very fragile and easy to break.
5. Sintering
In order to harden, the pressed blade needs to be heated. This work is done by sintering furnace. The sintering furnace can handle thousands of blades at a time. The pressed blade powder is heated to about 1500 ℃ in the process of up to 13 hours, and then melted into the hard alloy material. The shrinkage ratio in the sintering process is about 50%, so the size of the blade after sintering is only half of that before.
6. To be ground
Again, finish the quality inspection and grinding in the laboratory to the required thickness. Because cemented carbide is very hard, we need to use the world's hard material industrial diamond to grind it.
7. Grinding
When the blade reaches the required thickness, it will be further ground to obtain the geometry and size. This is a state-of-the-art grinding process at Kimer plant, which requires a 6-axis grinding plate to meet extremely stringent tolerance requirements.
8. Coating
After grinding, the blade is cleaned and the coating is removed. At this stage, gloves must be worn when handling blades to avoid any grease or dust. The blade will be placed on the fixture of the turntable and then fed into the coating furnace with lower pressure. That's where the blades come in different colors.
