Cutter head generally consists of four parts, including cutter teeth(alloy), cutter body, spring leaf and circlip, while only a few cover cutter teeth, cutter body and circlip, etc. Milling requires that the cutter teeth cut into the ground at first. Therefore, the cutter teeth must be of high shock resistance. Cutter teeth typically is sintered by coarse Tungsten Cobalt alloy powder in the vacuum environment, and then welded in the cutter body with features of flexural strength 2400n/mm² and density between 14.5-14.9cm³, which is high-density, high wear-resistance and strong shock-resistance.
Cutter body is usually made of wear-resistant material 42Crmo and processed by Cold Extrusion Molding Machine. With high flexural strength and high wear resistance, it is used to support and protect the cutter teeth. The circlip with high expansibility is locked on the hilt of the cutter head, which is compressed by the rolled steel 65Mo of high elasticity. It can firmly lock the cutter head for a long time and make sure the cutter head can rotate flexibly in the station. The spring leaf is locked on the circlip, which can enable the cutter head insert into the station easily. This can not only facilitate the assembly of the cutter head, but also safeguard the station effectively and let it be under normal abrasion. The spring leaf is typically made of wear-resistant materials by cold press technology. Its hardness is the important guarantee for the normal use of the cutter head, while the appropriate quench hardness can extend the cutter’s service life. The hardness of the cutter body is controlled between 44-48HRC and the cutter teeth is around 89HRA. High-frequency silvering or Nickel-based welding technology is employed to make sure the no-falling-off of the alloy cutter teeth.
The working principle of the Milling Cutter Head
The milling cutter head is fundamental in road construction. The cutter head works as its left and right hands, which is in charge of the most significant part: Milling surface. In order to finish the main cutting, the cutter head is made of large Tungsten carbide alloy particles and connected by soft Cobalt metal, whose hardness can be up to above 1400HV. Even under high-temperature and high velocity, it presents excellent refraction resistance and wear resistance. The cutting edge is in the shape of cone. The small top diameter can lower the cone performance and resistance when cutting further into the ground. The large bottom diameter of the top provide protection for the hand shank. The cutting edge is highly connected with the shank through special metal-braze welding. Besides the cutting edge, it also holds the shank and the bending moment of 6 ton-force in the 45 degree direction.
The key knife handle’s upper and bottom parts have different mechanical properties. The upper part has friction with ground and scraps the waste, which requires relatively high hardness. The pole from the bottom part inserts into the knife station to perform the scraping. Good tenacity allows it to take in inner strike. Therefore, the knife handle must be with dual performance: strong anti-friction and anti-breaking. There is a trunk in the center, where the patch clip can pull the knife edge out of the station. Without it, some knives may stretch out from the back through the sword shock. A few relatively new knife shanks have grooves on their head, which can strengthen rotation and prevent uneven abrasion in friction with the ground.