1. Concentration problem. Our products are usually 100% diamond concentration.
2. For grinding carbide workpieces with resin diamond grinding wheels, such as resin diamond grinding wheels D300*T25*H127*X10, 120# grit, wet grinding carbide, what is the recommended grinding wheel speed, feed rate, and feed speed?
Answer: The grinding wheel speed is lower than 35m/s, generally around 30m/s; the feed rate is generally 1 to 2 wires, depending on different grinding conditions;
3. Foreign customers have asked about bakelite matrix, the English name is Bakelite. What are the advantages of this bakelite matrix compared to aluminum matrix and steel matrix?
Answer: Bakelite matrix is formed by hardening phenolic resin and aluminum. It is elastic, has good thermal conductivity, and is light in weight.
4. For grinding wheels with metal binders, which are already known to be trimmed by electric machining, can they also be sharpened with corundum oilstone?
A: Yes, in fact, there are many ways of processing, such as electrical processing, grinding, electrolytic grinding, free grinding, etc. Generally, corundum and oilstone can be used. Don't make it too hard, and the dressing can't be too hard. The grinding wheel to be dressed must have a low speed.
5. What is the recommended concentration for metal sintered drill bits for glass opening?
A: This is related to the particle size. For sintered drill bits of 80/100, if the concentration requirement is relatively high for drilling rock formations, the harder the drill bit, the higher the concentration, and the softer the drill bit, the lower the concentration. Generally speaking, it is between 50-70.
6. Resin, ceramic, metal, what type of material is suitable for different binders?
Answer: Resin binders have weak holding power and are easy to fall off. Generally, type 1 material (RVD material) or resin polycrystalline diamond (short synthesis time, more aggregates are formed); ceramics generally use better type 1 material, type 1 and a half or type 2, but they are not very durable. Normally, it is type 2 yellow material, and it is best to use type 2 material; metal binders generally use types 2, 3, and 4. The formulas of metal binders include copper-based, cobalt-based, nickel-based, tungsten carbide-based and composite-based. There are many types of metal binders. Generally speaking, the stronger the holding power, the higher the diamond grade used. Metal binders are divided into metal sintering and bronze binders (bronze binders are 8515 and 8020 copper-tin alloys). The hardness is relatively low, and the higher the base is iron-based, nickel-based, cobalt-based, and the higher the base is tungsten carbide.
7. The influence of the linear speed of the grinding wheel on the use effect of the grinding wheel
Answer: There is an optimal linear speed of the grinding wheel. Generally speaking, if the speed is too low, the grinding is also large, and the binder wears quickly; if the speed is too high, the machine tool will vibrate greatly and it is not good for diamond. It is best to be moderate. Generally, the diamond grinding wheel is about 35m/s.
8. When rough machining cast iron/steel parts at the beginning, diamond can be used to replace CBN, and diamond honing can be used to process engine cylinders; I want to know under what processing conditions, diamond can be used to replace CBN to process iron metals.
Answer: Diamond can process non-metallic hard and brittle materials (marble, granite, ceramics, wear-resistant materials, sandstone, gemstones, semiconductors, glass, etc.), that is, non-metallic materials. Except for iron, cobalt and nickel, it can not process other materials. Because diamond is carbon, processing steel is prone to iron-carbon reaction, that is, the strength of diamond will drop sharply, because iron, cobalt and nickel are its catalyst and solvent; cast iron and iron are two different concepts. Stainless steel has the lowest carbon content, and cast iron has a carbon content of 2.46%. Iron and carbon are already saturated, and they will no longer react with diamond, so diamond can process cast iron molds. Diamond (durable) and CBN (sharp) can both be used to process cast iron. Why do we use diamond for honing? Because the crystal shape of diamond is complete and the surface texture of the processed surface is better. Processing tungsten steel: To be precise, tungsten steel is not steel but cemented carbide.
9. How is diamond classified?
Answer: It can be TI (cold punching) and TTI (hot punching). The more standard ones are cold punching and hot punching. TI (cold punching), the TI value of diamond represents its impact toughness. Take a certain amount of diamond sample and put it into the sample tube together with the steel ball. After the rated number of impacts, pour it into the test sieve for screening to measure its unbroken rate. TTI (thermal shock) characterizes its thermal shock toughness. A certain amount of diamond is heated to 1100℃ in a heating furnace for 20 minutes, and then impacted and tested for its unbroken rate. Now industry insiders believe that simply measuring TI or TTI values cannot fully reflect the performance of diamonds, and the difference between TI and TTI can better characterize its stability. Low-grade diamonds have many internal impurity defects. After calcination at 1100℃, a large number of "black spots" appear inside the crystal, and the overall color of the single crystal becomes darker, indicating that "internal injuries" have been caused inside the crystal after calcination. Most single crystals will break after impact. However, high-grade diamonds have fewer internal impurity defects. After calcination at 1100℃, only a small number of single crystals have small "black spots" inside, and most single crystals have not changed before and after calcination.
10. Diamond crystal form:
Answer: Crystal form: The particle size composition is divided into five parts: basic particles, coarse particles, coarsest particles, fine particles, and finest particles. The particle size of micro powder is generally not more than 2 times, and the size of crushed material is not more than 2.5 times. If it is longer, it will be scratched.
Type 1: needle-shaped, dendritic, incomplete crystal form (the bulk density and particle size composition can be detected, and the strength is generally not tested)
Type 2 material: equal-area shape, with some complete crystal faces.
Type 3: complete crystal faces account for 70-80%, and a small number of individual crystal faces are defective.
Type 4 material: hexaoctahedral, complete crystal form, good transparency.
11. What materials are generally selected for diamond tool grinding wheels?
Answer: Tool grinding wheels must have both strength and thickness, and they must be properly concentrated. If there are too many sharp surfaces, they will be worn out. If the strength is too high, it will not be able to hold it down. If it is too low, the diamond will break when it is ground. Generally, it is type 2 material with properly concentrated particle size.