Application of CBN/PCD tool in the field of track brake disc
In recent years, with the acceleration of urbanization and the increase of running speed, the disc brake device is more widely used. As one of the important parts in the disc brake device, the brake disc is to ensure the safe and reliable braking of the rail transit. ** Guarantee, especially for subways with short station spacing and short braking distance, the requirements for brake discs are higher.
At present, the material of the track brake disc is mainly divided into two categories: iron-based metal materials and composite materials, and iron-based metal materials include cast iron and steel systems. Cast iron materials are mainly gray cast iron, vermicular cast iron and ductile iron; steel optional materials are carbon steel, alloy cast steel and alloy forged steel.
The composite material includes an aluminum-based composite material and a carbon-carbon composite material, and is a novel material having excellent comprehensive properties, which is a composite material of a matrix material (metal, ceramic) and a reinforcement (fiber, whisker, particle), and has low noise. The vibration is small and the production efficiency is high, but the production process is demanding and expensive.
In order to better realize the efficient processing of the track brake discs, Valin Super recommends the use of cubic boron nitride (BNK30 and BN-S300 grades) and diamond cutters, which not only can easily meet the surface quality of the brake disc, but also effectively improve production. effectiveness.
As a pioneer in the localization of superhard tools, Valin has been working on cubic boron nitride tools and high-grade diamonds for the processing of brittle hard materials and difficult-to-cut materials. In recent years, innovative cubic boron nitride tools and diamonds have been developed. The tool is widely used in the fields of car grinding, ultra-high hardness and heavy-duty cutting, high-speed machining, and difficult material cutting. Among them, BN-S300 grade and BNK30 grade are used as the tool material for professionally processing gray cast iron track brake discs. Good processing performance.
BN-S300 grade is a monolithic CBN tool made of high-purity, high-purification raw material after high-temperature and high-pressure sintering. The CBN content is as high as 97%, and the **** has a static pressure mixing with Hualing** characteristics. Material technology, the blade has a very high density and uniformity, and the hardness is evenly HV3600. It has excellent wear resistance and edge strength, which makes it have longer tool life in continuous cutting and interrupted cutting.
BNK30 grade adopts the mixed ratio of imported nano-scale binder and high-purity submicron+nano CBN particles, and CBN polycrystals without cemented carbide support (substrate) sintered under high temperature and high pressure; its hardness is higher, CBN particle size is finer. It is especially suitable for high-speed finishing, which can obtain good and stable surface processing quality. At the same time, this CBN polycrystalline block can be fixed with any hard alloy substrate by high vacuum brazing process to form CNC tools of various shapes.
For composite brake discs, Valin super hard recommends diamond tool CDW010 material and CDW025 material. The above two materials are sintered by selected synthetic diamond microcrystals under high temperature and high pressure. Due to the addition of additives during the sintering process, the diamond tool has high hardness and toughness, and bending strength, which provides a new efficient processing method for composite brake disc processing.
