How to Choose Diamond Grinding Wheel Reasonably

2019-12-12 1026

(1) Reasonable Selection of Diamond Grinding Wheel - Workpiece Material

Different diamond grinding wheels should be selected for different workpiece materials and processing requirements. Even when grinding the same workpiece material, the grinding ratio of different materials of grinding wheels may differ by 2-5 times, so it is necessary to choose a suitable grinding wheel. Diamond grinding wheels are the best grinding tools for grinding hard alloys, ceramics, optical glass, gemstones, and stones with high hardness and brittleness. However, due to the simple carbonization of diamond at temperatures ranging from 700 ℃ to 800 ℃, it is not suitable for grinding materials with high iron content. The hardness of CBN is slightly lower than that of diamond, but it has good thermal stability (at temperatures ranging from 1300 ℃ to 1400 ℃), is chemically inert with iron group elements, has high thermal conductivity (46 times that of corundum), and the grinding wheel made of CBN has a long lifespan (up to tens to hundreds of times that of corundum grinding wheel). Unlike diamond, it does not differentiate (i.e. oxidize and graphitize) at high temperatures. It is a substitute for corundum grinding wheel to grind hardened steel, bearing steel, and high-speed tool steel The best grinding tool for high hardness and toughness metal materials such as stainless steel, heat-resistant steel, and titanium alloy. The bonding agents for diamond grinding wheels include resin, metal, ceramics, electroplating, and brazing. Based on practical application, selecting diamond grinding wheels with different binders is crucial for grinding power and quality.

(2) Reasonable Selection of Diamond Grinding Wheel - Binder

The bonding agents for diamond grinding wheels include metal, resin, electroplating, ceramics, and brazing. Metal bonded grinding wheels are used for cutting grinding, forming grinding of optical curve grinding, edge grinding of single edge cutting tools, and grinding of spiral grooves of small drill bits, and are also suitable for electrolytic grinding; Resin bonded grinding wheels are mainly used for edge grinding, measuring tools, grinding, cylindrical grinding, and surface grinding; Electroplated grinding wheels are suitable for high-speed precision grinding and forming grinding, as well as efficient hole grinding (warm grinding) and application on coordinate grinding machines; The ceramic bond grinding wheel has high grinding power, good shape retention, high durability, and is easy to repair. The diamond grinding wheel has a long service life, and due to the excellent chemical stability, heat resistance, acid and alkali corrosion of the ceramic bond itself, it can be used to various grinding fluids with low grinding costs. Therefore, it has now become the preferred grinding tool for efficient and high-precision grinding; Brazed grinding wheels are suitable for ultra high speed grinding. Different brands of abrasives have different crystal forms and particle shapes due to different manufacturing processes, and have different strength, thermal stability, and crushing characteristics. Therefore, different abrasives should be selected based on the type of binder, grinding material, and grinding method. For ceramic bonded diamond grinding wheels used for efficient and high-precision grinding, high-strength and sharp-shaped abrasives such as PDA type (artificial diamond type) and ABN800 type (CBN type) or other similar performance grades can be selected.

(3) Reasonable Selection of Diamond Grinding Wheel - Concentration

The superhard abrasive surface used for diamond grinding wheels can be coated with metal coating (metal coating can enhance strength and toughness, reduce thermal shock, and improve the performance of diamond grinding wheels by forming a bonding bridge between abrasive particles and bonding agents) or not coated with metal coating, which should be selected based on different conditions such as bonding agent type, workpiece material, dry and wet grinding. Copper coating is generally used for dry grinding. Currently, the coating metal has developed from nickel and copper to titanium, tungsten alloys, non-metallic ceramics, etc., from a single coating to a composite coating, and from abrasive coating to micro powder coating. The concentration of diamond grinding wheels cannot be selected too low, as high depth can bring high grinding ratio. In practice, diamond with a concentration of 200% is a common grinding wheel with diamond as the auxiliary material, and is generally not recommended for use. Nowadays, high concentration is used for high-speed and efficient grinding, and the concentration of ceramic bonded CBN grinding wheels for efficient grinding is generally higher. The concentration of ceramic bonded CBN grinding wheels is generally selected to be above 125%, such as imported matching ceramic CBN grinding wheels, whose concentration is generally between 175% and 200%.

Article source: Diamond grinding wheel