thin abrasive cutting discs for metal.

 1. Material research      Cutting disc is one of the key components of casting equipment. It requires good surface quality and high heat resistance. The strength and impact resistance of cast iron parts mainly depend on the number of alloying elements. Therefore, studying the material of castings becomes an important issue.  China cut off disc  2. The research of casting technology      In order to pursue high-performance cutting blades, the company puts higher requirements on the surface quality and processing precision of the cutting disc than the national standard. This puts high demands on the processing technology, and the thin flat cutting disc produced finally breaks through the difficulty of the casting process. .    3. The performance advantage of thin flat cutting disc      (1) Sharp cutting and high processing efficiency;     (2) High rigidity, long service life, high pressure work without pressure;     (3) High precision, can be used for precision cutting, smooth cutting without collapse;

Sintered diamond wheel introduction

Ceramic diamond wheel ceramic bond diamond grinding wheel has the common characteristics of diamond and ceramic bond. Compared with ordinary corundum and silicon carbide grinding wheel, its grinding force is strong, the grinding temperature is relatively low, and the grinding wheel wear is relatively small; The role of the coolant; the shape of the grinding wheel is good during grinding, the precision of grinding the workpiece is high; there are more air holes in the 7'' cut off disc for metal which is good for chip removal and heat dissipation during grinding, not easy to block and not easy to burn the workpiece; The self-sharpness is better, the trimming interval is longer, and the trimming is easier. Therefore, the use of ceramic bond diamond grinding wheels in some developed countries abroad is increasing.

Sintered diamond wheel

The metal bond diamond grinding wheel mainly has two types of sintering and electroplating depending on the manufacturing method. In order to give full play to the role of super-hard abrasives, foreign countries began to develop a new type of grinding wheel by high-temperature brazing process from the early 1990s, that is, single-layer high-temperature brazing super-hard abrasive grinding wheel. At present, this kind of grinding wheel is still in the research and development stage.

The sintered metal bond grinding wheel is mostly made of a metal such as bronze as a bonding agent, and is manufactured by a high-temperature sintering method. The bonding strength is high, the formability is good, the high temperature resistance, the thermal conductivity and the wear resistance are good, the service life is long, and a large load can be withstood. Because the grinding process of the grinding wheel inevitably has shrinkage and deformation, the grinding wheel must be shaped before use, but the dressing of the grinding wheel is difficult. At present, the common grinding wheel rolling method is not only time-consuming and labor-intensive, but also the diamond particles fall off during the dressing process. The dressing wheel itself consumes a lot and the shaping precision is low.

Metal cutting sheet hardening curve setting standard

The hardening process of the product in the production process of the cutting piece is a key node. Whether it is a metal cutting piece or other chemical cutting piece, if this node is not mastered, the quality of the subsequent product will be very problematic.

China cut off disc : setting of hardening curve In the resin grinding wheel manufacturing technology, there are two basic hardening curves, and all other hardening curves are the transformation of these two curves.

1. Short curve (rapid heating curve) The heating rate is faster, greater than 10 °C per hour. The total curve time is 20 to 24 hours. The curve is commonly used to harden the phenolic resin liquid as a wetting agent, and a certain amount of gypsum filler is added to the grinding wheel formula. The characteristic of the curve is: rapid hardening, and the phenolic resin powder used has a short flow length.

 2. Long curve (slow temperature rise curve) It is suitable for resin grinding wheel with good fluidity of medium (medium density, low viscosity liquid as humectant, etc.). The heating rate is slower during hardening, and the temperature rises by 3 to 5 °C per hour. It is kept at 120 ° C for about 4 hours, hardening temperature is between 160 ~ 190 ° C, the total length of the curve is 40 ~ 60 hours.

The principles to be followed for the hardening curve design:

1.large-diameter standard cut off wheel for metal, high-thickness grinding wheel, the curve temperature holding time should be long when hardening, to ensure the hardening is complete;

2.When the cutting piece is not completely hardened, the curve temperature needs to be lowered;

3. When the high-hardness cold-pressed grinding wheel is hardened, the holding time in the range of 105-120 °C must be extended to allow the volatile matter to be completely released;

4. When the resin cutting wheel is hardened, the heating rate is fast, so as to ensure sufficient fluidity of the bonding agent, thereby obtaining product performance. Short curve, low temperature hardening, can produce "soft" grinding wheel; Conversely, when producing "hard" grinding wheel, the temperature is lower than 160 °C, the grinding wheel strength is low, the grinding effect is weak, the grinding wheel is soft; when the temperature is higher than 210 °C, the hardening Excessively, the produced cutting pieces are brittle and easily broken.

High speed grinder

The high speed grinder shift control method belongs to the field of ultra-precision machining technology. The known technology is to start the grinding machine. After overcoming the inertia, the rotation speed of theChina supply 7" cut off disc tool directly refers to the official grinding speed, and the machining stops, and the rotation of the grinding tool stops after a certain period of time under the action of inertia. The machining accuracy of this method is not guaranteed and the machining efficiency is low. The invention controls the change of the rotating speed of the grinding tool at the beginning and the end of the grinding process, so as to have a slow, rapid and slow speed increasing and slowing down process. The effect is that the impact of the abrasive tool and the surface of the workpiece is greatly reduced, and the occurrence of scratches is avoided, thereby improving the processing precision and the processing efficiency. The invention can be applied to the grinding process of a high-speed grinder, and performs surface grinding processing on workpieces such as cemented carbide and engineering ceramics.

A high-speed grinding machine shift control method has three stages of grinding, namely, a start stage, a formal stage and an end stage. At the beginning stage, the grinding tool is rotated at a constant speed, the official stage grinding wheel is rotated at a constant speed, and the end stage grinding tool is rotated at a reduced speed. The characteristic is that at the beginning of the grinding process, the acceleration of artificially controlling the rotational speed of the grinding tool increases from zero to fast. When the rotational speed of the grinding tool rises to half of the official grinding speed, an inflection point occurs in the change of the acceleration, and the rotating speed of the grinding tool is controlled. The acceleration decreases from the maximum to the slowest until the grinding speed reaches the official grinding speed, and the acceleration of the grinding speed decreases to zero.

The emergence of diamond tools

Diamond and CBN grinding wheels are the most typical tools in superhard material tools. They are made of diamond or CBN, which have certain shapes, properties and uses under certain production conditions by means of bonding agents or other auxiliary materials. The product. Diamond and CBN cut off disc for stainless steel can be mainly classified into metal bonding agents, ceramic bonding agents and resin bonding agents according to the type of bonding agent.

With the development of super-hard material tool technology, its machinable objects cover almost all known materials, greatly improving the processing efficiency and processing quality in various mechanical precision machining fields, especially as high-speed, precision, numerical control, and fine An important part of advanced manufacturing technology such as processing, its application mainly has two major fields: First, the field of hard and brittle materials processing, mainly refers to sapphire, monocrystalline silicon, polycrystalline silicon, magnetic materials, silicon carbide, refractory materials, glass, geological drilling, etc. Hard and brittle material processing; second, a variety of mechanical precision processing, mainly refers to electronics, machinery, automotive, new energy and other precision processing. According to their different uses, they can be divided into: diamond grinding wheel, diamond sawing wheel, diamond drilling head and other major categories.

The emergence of diamond tools has made history a way of relying on heavy manual labor and low-efficiency processing of hard and brittle materials. Instead of modern and advanced processing methods of mechatronics, the processing efficiency can be greatly improved. Diamond grinding wheels are made of magnetic materials. The field of hard and brittle materials such as sapphire, silicon, building ceramics, stone, reinforced concrete, etc. is currently the most effective tool.

Ordinary abrasive consolidation characteristics

The items that represent the characteristics of ordinary cut off disc for stainless steel bonded abrasives are:

Shape, size abrasive, particle size, hardness, texture, back pile, backing and bonding agent. Abrasive hardness refers to the difficulty of the abrasive particles falling off the surface of the abrasive tool under the action of external force. It reflects the strength of the abrasive particles held by the bonding agent.

The hardness of the abrasive tool mainly depends on the amount of the binder added and the density of the abrasive. The abrasive particles are easy to fall off, indicating that the hardness of the abrasive is low; otherwise, the hardness is high. The hardness grades are generally divided into seven levels: super soft, soft, medium soft, medium, medium hard, hard and super hard. From these levels, several small levels can be subdivided. The method for determining the hardness of the abrasive tool is more commonly used by a hand cone method, a mechanical cone method, a Rockwell hardness tester method, and a sand blast hardness tester.

The hardness of the abrasive tool has a corresponding relationship with its dynamic elastic modulus, which is advantageous for determining the dynamic modulus of the abrasive tool by the audio method to indicate the hardness of the abrasive tool. In the grinding process, if the material of the workpiece to be ground is high in hardness, a grinding tool having a low hardness is generally used; and vice versa, a grinding tool having a high hardness is used.

Abrasives are roughly classified into three types: compact, medium, and loose. Each class can be subdivided, etc., and is distinguished by the organization number. The larger the abrasive tissue number, the smaller the volume fraction of the abrasive in the abrasive tool, and the wider the gap between the abrasive grains, indicating that the tissue is looser. Conversely, a smaller organization number indicates a tighter organization. The abrasive material of the looser structure is not easy to passivate when used, and has less heat during the grinding process, and can reduce the heat deformation and burn of the workpiece. The abrasive grains of the tighter structure are not easy to fall off, which is beneficial to maintain the geometry of the abrasive tool. The organization of the abrasive tool is controlled only by the abrasive formula at the time of manufacture, and is generally not measured.

Characteristics of the centerless cylindrical grinding form

There are many features to be noted in the form of centerless cylindrical grinding. When we use thin flat cutting disc , we should understand the form characteristics of the cylindrical grinding workpiece and provide some help for our own processing. Some forms of cylindrical grinding workpieces are summarized and introduced by manufacturers and companies for us to understand.

1. Since the workpiece is often indeterminate center, the workpiece is ground in the outer circle without the center hole and the ejector pin is used to support the workpiece. Therefore, the grinding allowance is relatively reduced.

2. The manufacturer believes that cylindrical grinding can not grind the axially grooved workpiece, because when grinding the holed workpiece, the axial position of the workpiece hole cannot be corrected, resulting in lower coaxiality of the workpiece.

3. Internal grinding of workpieces can only be processed on workpieces that are rolled on rollers without special circumstances, such as thin-walled parts such as grinding kits. Grinding parts are based on their own outer circle as the positioning reference. Therefore, the original coaxiality error between the inside and the outside cannot be corrected.

4. The centerless grinding maneuver time coincides with the loading and unloading time, which is easy to automate the grinding process and has high production efficiency.

5. In the centerless grinding process, the position change of the center of the workpiece depends on the original error before grinding, the rigidity of the process system, the grinding amount and other process parameters (center height of the workpiece, pallet angle, etc.);

6. The stability and uniformity of the motionless workpiece grinding depends on the machine drive chain, the shape of the workpiece, the weight, the material of the guide wheel and the support, the surface shape, the grinding star and other process parameters.

7. The adjustment time of the centerless grinding machine is long, and the technical requirements for adjusting the machine tool are also high. It is not suitable for single-piece small batch production.