Powder
Tungsten oxide is mixed with carbon and processed into tungsten carbide in a special furnace, which is the main raw material for all cemented carbide. Tungsten carbide is an extremely hard and fragile material that is used as the main component of sequila cemented carbide. Tungsten carbide is mixed with cobalt, which is essential for the properties of cemented carbide. The more cobalt, the better the toughness of cemented carbide; On the contrary, the harder and more wear-resistant it is. The weight ratio of the different ingredients is carried out with the highest precision. The error of raw materials of a batch of 420 kg shall not be greater than 20 grams. Mixing is a delicate metallurgical operation, and finally, the mixture is ground into a delicate and delicate powder in a large ball mill. The mixture must be spray dried to obtain the correct flowability. After grinding, the particle size of the powder reaches Ø 0.5-2.0 um.
Pressing
The initial press is carried out with punches and dies in a highly automated CNC-controlled press to obtain the basic shape and size. After pressing, the blade looks very similar to a real carbide blade, but the hardness is far from up to standard. The robot transfers the pressed blade to a disc made of heat-resistant material.
Sintering
For hardening, the blade undergoes a heat treatment of 15 hours at 1500 degrees Celsius. Through the sintering process, the melted cobalt is bonded together with the tungsten carbide particles. The sintering furnace process does two things: the blade shrinks significantly, and the shrinkage must be accurate to obtain the correct tolerances; Secondly, the powder mixture is transformed into a new material with metallic properties and becomes cemented carbide. Now, the blade has reached the expected hardness, but not to the point where it can be delivered. Before proceeding to the next stage of production, we carefully check the size of the blades in the coordinate measuring machine.
Grinding
Only by diamond grinding can the carbide insert have an accurate shape. Inserts are ground according to the geometric angle requirements. Most grinding machines have built-in measurement controls that check and measure the blades in several stages.
Edge treatment
The cutting edge is processed to obtain the correct shape to achieve the maximum wear resistance required for machining. These blades can be brushed with a special brush coated with silicon carbide, and the final result must be checked regardless of the processing method. 90%-95% of all inserts have some kind of coating, to ensure that the blade surface is free of any foreign particles, to prevent such particles from adhering to the coating, thereby affecting tool performance.
Coating
Chemical vapor deposition (CVD) and physical vapor deposition (PVD) are two existing coating methods, and which method to choose depends on the material and processing method. The thickness of the coating depends on the blade application, and the coating determines the durability and life of the blade. The technical know-how is that the surface of cemented carbide is coated with many extremely thin coatings, such as titanium carbide, aluminum trioxide and titanium nitride, which can greatly increase the service life and durability.
If the CVD method is used to coat, the blade is put into the furnace, along with methane and hydrogen, chlorides and oxides in the form of gases are added, and when they reach 1000 degrees Celsius, these gases interact and also act on the surface of cemented carbide, so that the blade obtains a homogeneous coating of only a few thousandths of a millimeter thick. Some coated blades gain a golden surface and become more valuable, with 5 times more durability than uncoated blades. PVD, on the other hand, sprays the blade at 400 degrees Celsius.
Final inspection, marking and packaging
The blades are inspected automatically, and then we laser-label the material on the blades and finally pack them. The blade box is marked with product information, serial number and date, which is Seco's commitment to ensuring excellent quality and service.
Warehouse
Once packaged, the blades are ready for delivery to the customer. Logistics centers are available in Europe, the USA and Asia to ensure that blades are delivered quickly and intact to customers.