Wear stage of diamond grinding blocks

Diamond is the hardest material in nature. Diamond grinding wheel and diamond saw are diamond tools. They are mainly used to process hard and brittle materials. Various tools have different processing characteristics, and the scope of application is not the same, but its The wear principle during use 7'' cut off disc for metal is basically the same. Hard and brittle materials will produce high temperature and high heat due to the intense friction during processing. This wear process has to go through three stages, that is, the wear process has a transitional stage. The stages are: fast wear stage, stable wear stage, in which the wear rate is about constant and the wear rate is relatively constant, and the third stage is the accelerated wear stage.

Continuous research has found that the wear of the grinding wheel is different during the transition phase and the stable wear phase. In the transitional stage, the wear and the preparation method of the grinding wheel, the material characteristics and specifications of the grinding wheel are closely related. The wear in the stable stage is mainly friction and wear, the abrasive wear is mainly friction wear, and the final accelerated wear stage is Most of you are worth noting, because at this stage, the wear and tear of the tools has reached the maximum.

Sintered diamond wheel

By mklyk, 2018-12-07

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.

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.

The world's superhard material tools are produced all over the world. Among them, 12 inches cut off wheel tools are manufactured in Japan, Germany, the United States and South Korea. These countries are rapidly turning tools for superhard materials. Other abrasives have been used. It is decreasing year by year. Because of its high efficiency, energy saving, long life and environmental friendliness, super-hard materials have ten times higher efficiency and life than traditional tools.

 China's superhard materials industry began in the 1970s. Prior to this, almost all of the super-hard material tools such as diamond saw blades were imported. In the 1980s, a large number of production enterprises mainly producing small-diameter diamond saw blades were launched, and the high-speed development period began in the 1990s. The super-hard material tool industry has realized a complete industrial system with complete scale and considerable scale, from the end to the present, including the supporting raw material supply system, equipment supply system, auxiliary material system and market system. Produce tools for superhard materials that basically meet the needs of the development of various industries. There are still a large number of products exported every year, especially in the middle and low-end products, but at the high-end product manufacturing and technical level, compared with the advanced level of foreign countries. There is a certain gap.  

 With the continuous advancement of science and technology, the unique properties of super-hard materials have been continuously developed and utilized. The technical level of super-hard materials has been continuously improved, and the application fields have been continuously expanded. The super-hard material products industry has become an indispensable important part of national economy and national defense construction. component. With the maturity of synthetic diamond technology and the rapid development of China's economy, diamond tool manufacturing technology has accumulated and progressed, and has strong manufacturing capabilities.

Due to the advantages of enterprises in labor costs and the subsequent catch-up situation in technology research and development, Chinese enterprises have obvious advantages in product cost performance. With the rapid growth of market demand, diamond tool companies all over the world have launched, and a number of advantageous enterprises with international competitive strength have emerged. China has become an important producer, user and exporter of diamond tools in the world, with an annual output value exceeding 10 billion yuan. The application of diamond tools in emerging industries is expected to expand further with the increasing grade of synthetic diamonds. Its excellent performance is expected to be widely used in high-tech fields, such as machining of precision instruments such as aerospace instrument bearings, radar waveguides, optical devices, high-energy smokers, etc.; can be used for single crystal silicon, polycrystalline silicon 0.1-0.2mm High-precision precision machining such as cutting, grinding, and satellite solar panels for thickness sheets; it can be used for micro-precision cutting, slotting, back-thinning, and nano-diamond polishing of large-scale integrated circuits such as computer chips. The developed countries in the world all regard superhard materials and products including synthetic diamonds as the development focus. The research and application level of superhard materials and their products represent the level of scientific and technological development of a country to some extent.

2018 China (Guangzhou) International Abrasives Grinding Exhibition opened in Guangzhou Pazhou International Convention and Exhibition Center. 2018 China (Guangzhou) International Abrasives Grinding Exhibition is themed on abrasives, abrasives, superhard materials and grinding products, covering the latest technology and products in the abrasive grinding industry. It is specialized in providing grinding solutions. The first professional grinding technology exhibition in the region. Guangzhou Sanmao Exhibition will gather the largest and largest mainstream abrasives and abrasives enterprises in Guangdong Province and its surrounding areas, fill the gap of the three-grinding industry in South China, open up the technical and information exchange barrier, and focus on the market of abrasives and abrasives. The industry provides a quality platform for user needs, technical support, and product circulation.

The exhibits of this year's exhibits are divided into several categories, including abrasive abrasives and raw and auxiliary materials, abrasive abrasive manufacturing and testing equipment, grinding processing related equipment and tools, including but not limited to:

Superhard materials and products - synthetic diamond, cubic boron nitride and its micro-powder, PCD, PCBN, CVD diamond film and thick film / super hard material grinding, cutting, drilling, polishing and other tools.

Ordinary abrasives and products - corundum, silicon carbide (boron) and other ordinary abrasive / ordinary fixed abrasive / refractory materials. Coated abrasives - abrasive cloth, sandpaper and various shaped coated products. Raw and auxiliary materials - raw materials, 7'' cut off disc for metalmolds, various bonding agents, metal powders, binders, substrates, etc. for the manufacture of superhard materials and ordinary abrasives. Grinding related equipment and tools - grinding machines, grinding centers, electrical processing equipment, grinding machines, polishing machines, honing machines, lapping machines, grinding robots and various accessories and related auxiliary materials and products; metal forming machine tools , metal cutting and welding equipment, CNC systems and functional components, industrial automation, machine tool accessories and components; various tools, tools, measuring tools, etc.

Special equipment for the manufacture and testing of abrasives - synthetic diamond press, shape selection machine, screening machine, magnetic separator, shaker, mixing machine, forming machine, hot press, cold press, sintering furnace, welding machine, Laser cutting machine, corundum and silicon carbide smelting furnace, crushing and milling machine, firing and hard (sulfur) equipment, grinding wheel processing equipment, abrasive cloth manufacturing equipment and various abrasive tools testing equipment.

The International Abrasives Grinding Exhibition aims to create an integrated platform for abrasive grinding technology and equipment in South China, providing a reliable one-stop solution for the industry.

Abrasive companies keep pace with the times

Adapting to the trend is to keep pace with the times, the needs of abrasives companies are constantly changing, China supply 7" Cut off disc The market update is also promoting the pattern of abrasive companies. Small abrasives companies must have industry vision, follow national policy trends, and explore new ways to explore the future of the company.

1, adjust the residual structure, streamline the processing mode to suppress excess capacity.

Achieving the ability to create manufacturing capabilities when manufacturing standard cutting discs, producing standards with innovative Cut off disc for stainless steel products, to achieve this goal, the first thing to have a business development strategy. We all know that whether it is industry development or enterprise progress, we must formulate strategic development plans. This is the goal of advancement to prevent blind and more mad development. After all, the production of low-end abrasives is in a state of overcapacity. Only by completing the tasks of structural adjustment and transformation of development methods, strive to develop healthily and rapidly. Through the whole industry, we will cultivate a group of large and powerful enterprises and a small number of small and specialized small giant enterprises to enhance the core competitiveness of the industry.

2. Enhance the intensity of independent innovation and research input.

And actively explore joint research on production, learning, research, and new methods. Through the development of the brain, we can introduce technology and talents, and actively develop high-end products. The focus of grinding is on deep processing product development. To meet the rapid growth of the photovoltaic industry and engineering ceramics and refractory market demand.

3. Promote green manufacturing.

Green manufacturing refers to modern manufacturing models that consider environmental impact and resource efficiency while ensuring product functionality, quality and cost. It is the development trend of the mechanical manufacturing industry in the 21st century. It is an application that realizes energy conservation and recycling of resources, minimizes the impact on the environment, and establishes an important way of resource conservation and environmental friendliness.

Green manufacturing includes energy conservation and emission reduction. This work is a more prominent problem in the abrasives industry. Although the abrasives industry has not yet been included in the “two highs and one capital” industry, the National Development and Reform Commission's abrasive grinding industry includes the survival of enterprises. At the bottom line, our business is to learn new technologies, such as energy conservation and emission reduction, new technologies, the development of circular economy, and the full implementation of green manufacturing.

Grinding wheel particle size selection

The particle size of the grinding wheel is to crush, roll and process the smelted crystal block, and then screen the fine powder of different sizes of particles, wherein the particle size is represented by a number, which is called particle size. The particle size is generally expressed by the number of the sieve, that is, the sieve hole per inch length, and the larger the number, the smaller the abrasive grain.

thin flat cutting disc Granular choice

The wheel size is a measure of the size of the abrasive particles. The choice of grinding wheel size directly affects the surface roughness and grinding efficiency of the workpiece. In general, the grinding efficiency is high when grinding with a coarse-grained grinding wheel, but the surface roughness of the workpiece is poor. When grinding with a fine-grained grinding wheel, the surface roughness of the workpiece is good, but the grinding efficiency is low. In short, under the premise of meeting the surface roughness requirements of the workpiece, the abrasive tools with coarser grain size should be selected as much as possible to ensure high grinding efficiency.

Usually the choice of grinding wheel size is determined according to the grinding needs. usually:

Rough grinding: steel ingots, forged castings, leather wood, cut steel billets, etc., for 12#. 30#

Semi-finishing: used for rough grinding of plane, outer circle, inner circle, centerless grinding, etc., applicable to 36#

General fine grinding: used for outer circle, inner circle, plane, centerless, tool grinding machine and various special grinding machines, etc., applicable to 60#

For fine grinding, honing, threading, etc., for 120# one W20

Super fine grinding: fine grinding, super fine grinding, mirror grinding, etc., for W20