The application of super-hard abrasive CBN and vitrified grinding wheel

The super-hard material CBN invention can be used as an abrasive for the manufacture of a grinding wheel, which not only can effectively process the harder steel (HRc 45-65), but also improves the durability of the grinding wheel by a plurality of times.

In particular, in the mid-1980s, the research and development of the CBN grinding wheel of the ceramic bonding agent, in particular the technical breakthrough in the correction of the sharp, can be said to be a revolution of the grinding mold in the mid-1980s, in particular by the German Krebs & Riedel. Classification of CBN Grinding Wheel The grinding wheel made of CBN grinding material can be divided into the following four kinds according to different processing technology and the binding agent of different components used. Their properties and uses (refer to the use of machining) are also different.

(1) Electroplated CBN/ diamond grinding wheel The production process of the grinding wheel is simple, and the production cost is low. The molding is simple but only one layer of coating can not be corrected. In the processing, it is hard to know when the grinding layer is damaged. Is suitable for small-batch machining and geometric complex forming and grinding processing and is used as a correction roller.

(2) sintered CBN/ diamond grinding wheel The invention has the advantages of high hardness and high density, and high-precision correction roller, and has high cost. Which is mainly used for the processing of a correction roller and a large-scale super-hard material used as a grinding wheel.

(3) Resin CBN/ diamond grinding wheel The production process of the grinding wheel is simple, and the production cost is low. The forming is simple but it is not good to correct the integer. For multi-type small-batch processing. Such as tool grinding and cutting of the tool, and processing of the glass.

(4) The CBN/ diamond grinding wheel of the ceramic binder is the most suitable for mass production and the fastest development. The formulation of the processing process and the binder is in the hands of a small number of foreign manufacturers, such as the German Krebs & Riedel, the world's largest abrasive mold group, the WINTER, the Austria's TYROLIT, Germany's Wendt and the Swiss WINTER HUR, which have just entered the Chinese market.

In the 1990s, domestic production and technology were at least 10 years behind foreign technology. In addition, due to the fact that the domestic CBN grinding machine is less than 10 years behind the domestic CBN grinding wheel, the reason for low domestic penetration rate is not high. The grinding of 70% of foreign auto parts is finished by CBN grinding wheel! The CBN/ diamond grinding wheel of the ceramic bonding agent has the advantages of strong grinding force, high-speed processing of the non-burn workpiece, can be modified and durable, and the like, and is the most ideal high-speed, high-efficiency and high-precision grinding tool.

In the developed industrial countries, for large-scale and high-precision grinding, the hardness of the workpiece is higher than 45, and the grinding of the grinding wheel of the ceramic CBN wheel is basically used. It is widely used in the main parts of the automobile, such as the camshaft, the crankshaft, the gear shaft of the transmission, the gear, the bearing and the brake block, the outer circle grinding of the horn-like valve and the groove grinding (metal CBN grinding wheel), and the automobile steering pump part (the representative) and the universal joint component. Grinding the parts of the air-conditioning compressor, grinding of the parts of the printing machine, and making the precision reach the size of 0,3-0 and 5 microns by grinding the parts of the precision workpiece such as the guide rail, the lead screw and the motor shaft of the machine tool, the grinding of the parts of the air-conditioning compressor and the grinding of the parts of the printing machine.

The application of CBN-ceramic grinding wheel to the grinding and processing of steel-rolled roller and its application in the fields of aviation, space and military industry is not one point, and the application of grinding wheel is discussed with the following examples as examples. The grain size of the CBN is fine, the roughness of the workpiece is small (that is, the smoothness is high), the grain size is coarse, and the grinding amount of the workpiece is large. Therefore, the coarse-grained CBN grinding tool can be selected as much as possible on the premise of meeting the roughness. In that same way as the CBN tool, for example, the number BN-H10 and BN-S20 of the CBN tool of the vehicle are common, the former has small particle size, is suitable for finish machining with the balance of less than 0.3 mm, and the roughness of the hard steel can reach Ra0.4; and the latter adopts medium particle size, and is suitable for large-margin cutting and hardening steel, and the eating knife can bear about 7 mm. The low cbn content is more brittle than the high cbn content, but they are used to quench the hard ferrous metal processing. Their lower thermal conductivity and the relatively higher compressive strength of the heat produced by high-speed cutting and negative rake angles. The higher temperature of the cutting zone softens the workpiece material and helps to break the chip, while the negative rake angle strengthens the tool so that the cutting edge is stable.

The binder used in the grinding wheel shall also be taken into account when selecting the grain size of the CBN grinding wheel, since the various binding agents have its optimum particle size range, too thick or too fine to be detrimental to the grinding process. In general, the resin binder CBN grinding wheel is generally 100/120-270/325; the ceramic binder CBN grinding wheel is generally 100/120-230/270; the metal binding agent grinding wheel is 70/80-230/270. It is of course also to select the optimum particle size, such as the processing efficiency and the surface roughness requirement, and to select the coarser grain size when the processing efficiency is high. On the other hand, the fine grain number is selected. It is known that the manufacturer of the domestic ceramic CBN grinding wheel is not much, the first of the three mills in Zhengzhou, but the gap between the production technology and the R & D technology and the foreign countries is larger, especially the ceramic bonding agent CBn grinding wheel, and the stability is one of the most common problems of the domestic super-hard abrasive tool manufacturers and users.