The dicing sheet is a porous body obtained by compacting, drying and sintering an abrasive and a bonding agent. Abrasives, binders, and pores constitute the three elements of the composition of the cutting piece. The performance of customized metal cutting disc depends on five parameters of abrasive, particle size, binder, hardness, and texture.
It undertakes cutting tasks and has high hardness, wear resistance, heat resistance, and toughness, and has sharp edges and corners. Commonly used abrasives are an oxide, carbide, and high hard grinding. The main component of the oxide-based abrasive is A1203, which is classified into different varieties because of its different purity and addition of metal elements. Carbide-based abrasives are mainly based on silicon carbide, boron carbide, etc., and are also classified into different varieties depending on the purity of the materials. Among the super abrasive systems, there are mainly synthetic diamond and cubic boron nitride. Cubic boron nitride is a promising abrasive. Heat resistance (1400 ° C) is much higher than diamond (800 ° C), and chemical inertness to iron, so it is particularly suitable for grinding hard and tough steel.
The particle size indicates the extent of the abrasive particles. The particle size of the abrasive particles is indicated by the mesh number of the screen through which the abrasive particles can pass. The particle size number is expressed by the number of sieve holes per inch length. The larger the particle size number, the smaller the particle size; the fine powder having a size smaller than 40 μm, and the actual size is preceded by W to indicate the particle size number. The metric unit is used in the new standard in China, and the size of the abrasive grains is uniformly expressed by the size in the direction of the largest dimension of the abrasive grains.
1. Finely ground abrasive grains for fine grinding;
2. Coarse grinding particles with coarser particles;
3. Coarse particles with high grain grinding for high-speed grinding;
4. When the workpiece material is soft and plastic and the grinding area is large, in order to avoid clogging the cutting piece, coarser abrasive grains may be used, and fine grinding grains may be selected for fine grinding or grinding hard and brittle materials.
The role of the bonding agent is to bond the abrasive particles together so that the cutting blade has the necessary shape and strength. Commonly used low price disc for metal.
The bonding agent is:
1. Ceramic bond (code V) is formulated from ceramic materials such as clay, feldspar, talc, borosilicate, and silica. It is characterized by chemical stability, water resistance, acid resistance, heat resistance, and low cost, but is brittle. Most of the dicing sheets use a ceramic bond in addition to cutting the dicing sheet. The line speed of the cut piece produced by it is generally 35 m/s.
2. Resin binder (code B) The components are mainly phenolic resins, but epoxy resins are also used. The resin binder has high strength and good elasticity, so it is often used in high-speed grinding, cutting and grooving. However, the heat resistance of the resin binder is poor, and when the grinding temperature reaches 200 to 300 ° C, its bonding ability is greatly reduced. With its reduced strength, the abrasive particles are easy to fall off and reveal sharp new abrasive particles (self-tanning), in some processes that are particularly sensitive to grinding burns and grinding cracks (such as grinding thin-walled parts, super-fine grinding or sharpening) A resin binder can be used for the cemented carbide or the like.
3. The rubber bonding agent (code R) Most of them use synthetic rubber. The rubber binder is more elastic than the resin binder, and the cutting sheet has a good polishing effect. It is mostly used to make guide rollers for centerless grinding machines and to cut, groove and polish cutting sheets. However, it is not suitable for use as a rough cut.
4. Metal bond (code M) Commonly, a bronze bond is mainly used for making diamond cut pieces. The bronze bond diamond cutting piece is characterized by good formability, high strength, and a certain toughness, but poor self-tanning. Mainly used for rough grinding, semi-finished hard alloys and cutting optical glass, ceramics, semiconductors, etc.