Tungsten carbide disc cutter is fabricated by pressing and sintering process, which has good toughness, abrasion resistance, anti-oxidation and crater wear resistance. So it can be widely used in paper cutting, printing, packaging and some electronic fields. Take metal sheet longitudinal cutting as example, it generally uses a pair of upper and lower disk cutter for rolling-shearing process. In the cutting process, the upper and lower disk cutter to maintain the level in the axial gap and radial transfer volume, driven by the rotation of the sheet metal disc cutter is equal to the circumferential velocity cutting discs and gradually into the upper and lower circular knife the edge effect zone, sheet metal cutting edge is cutting discs continue to cut and shear deformation until completely separated. By circular knives and down when pressed into the sheet metal cutting discs elastically deformed by the active region, the shear force suffered from scratch increases, when the sheet is in elastic deformation stage; with the rotary disc cutter, cutting edge up and down cutting discs gradually close the sheet by shearing force continues to increase and the elastic limit of the material reached and shear plastic deformation material into shear deformation stage; thereafter, the shear continues to increase until it reaches the ultimate strength of the material, the material into the crack propagation stage.
Although the working temperature of disc cutter is not so high, it still has large contact pressure to the metal plate. So its wear forms mainly include Co-loss wear, fatigue wear, abrasive wear and adhesive wear.
Co-loss wear: The binder phase Co loss partially, so the bonding strength of WC is weakened and isolated, even drops, which causes the strength, toughness and wear resistance decreasing;
Fatigue wear: due to stress concentration, crushing, shearing and friction prone to fatigue alternating stress micro-cracks in the edge region, and extend toward the center of the knife along the side of the disc;
Adhesive wear: disc cutter and the side sheet metal sub-section is greater pressure contact state, the cutting knife in cold welding material portion side disc. The adhesive layer in the process of continuous cycle cutting off, which wear process aggravated.
