Vacuum Brazing Technology of Diamond Grinding Wheel

---

SIMUWU has many years of experience in the field of vacuum brazing and is committed to the manufacture of vacuum brazing furnace equipment. This article will introduce the vacuum brazing process associated with diamond grinding wheels.

Brazed diamond grinding wheel is a large diamond-like grinding wheel, which is made of diamond as cutting material and brazing filler metal as binder, which is brazed in vacuum or protective atmosphere to connect single-layer abrasive and metal matrix through high-temperature brazing of chemical metallurgy. . Diamond brazing products are high-tech products that very few domestic manufacturers have started mass production in recent years, and have gradually replaced some diamond electroplated grinding wheels and some diamond sintered grinding wheels.

Compared with other diamond products, brazed diamond grinding wheels have the following characteristics: the grinding efficiency of single-layer diamond brazing products is 1-2 times that of electroplating products, and 2-5 times that of other diamond sintered products; single-layer diamond brazing products The product has a long service life, which is 2 to 3 times that of electroplating products. The service life and efficiency of multi-layer diamond brazing products are 1 to 2 times that of sintered products with the same working layer height, energy saving and environmental protection.

The manufacturing process of the brazed diamond grinding wheel includes the following three stages: matrix processing, matrix pre-welding treatment, and brazing.

The single-layer abrasive brazing procedure mainly includes the following steps: abrasive arrangement → brazing material → brazing.

Common brazed diamond grinding wheels: brazed forming grinding wheels, brazed diamond forming grinding heads, brazed diamond bushing knives, brazed diamond wire saws, brazed diamond thin-wall drills.

1. Diamond: The diamond used for brazing diamond grinding wheel should have a relatively coarse grain size. For example, the grain size of diamond for manufacturing core drill bits can be about 46/60, the single particle compressive strength is above 16kg and the abrasive has been subjected to strong magnetic separation.

2. Solder: The solder BAg612 has good fluidity and high strength in use, but because of its high silver content, the price is high. Usually, Z31, Z41, Z51 and other solders can be used. The ZB-1 brazing material developed by Zhang Guanxing and others is moderate in price, and the brazing temperature is 760~780℃.

3. Flux: Use rosin + alcohol as flux and do not clean it after welding, because it is non-corrosive. If the flux containing chloride and fluoride is used, it needs to be cleaned after welding to avoid corrosion of the parts. J102 flux is composed of potassium fluoride 42% + potassium fluoroborate 23% + boric anhydride 35%, which can be used for welding steel, stainless steel and cemented carbide. Before welding, deionized water can be used to adjust the flux into a paste and apply it to the welding surface.

4. Substrate: The substrate can be made of aluminum, steel, alloy steel or hard alloy, and the surface of the substrate should be sandblasted, cleaned and dried. Cleaning can be performed with acetone, oxalic acid, citric acid or warm water.

5. Fabric: matrix → flux → solder → diamond → solder

If orderly cloth is used for diamond: generally point glue distribution method, template cloth method, laser scanning method, vacuum adsorption method, etc., but certain special equipment is required.

6. Welding: high-frequency welding can be used for general grinding wheels, and precision grinding wheels should be welded in a vacuum furnace or filled with protective gas. The vacuum furnace pressure is about 10^-4Pa. The brazing temperature should be more than 50℃ higher than the melting point of the brazing filler metal. After welding, it should be kept at 200℃ and gradually cooled.

Selection of vacuum furnace equipment: According to the process requirements, low-temperature vacuum brazing equipment with good vacuum degree, high temperature control accuracy and good temperature uniformity in the furnace should be used as far as possible to braze the diamond grinding wheel.

The RVB-L series vacuum brazing furnace designed and manufactured by SIMUWU has good temperature uniformity, the vacuum degree can fully meet the process requirements, and realizes the automation of operation, saving a lot of labor costs. Model size can be customized to meet customer requirements. SIMUWU is equipped with a dedicated team of engineers who can provide the most professional supporting services to meet the needs of various producers to the greatest extent.