Tool vacuum brazing

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Brazing is a type of welding process that is widely used in many industries. In the welding process of the tool making process, the brazing process is mostly used.

The definition of brazing: adding solder (solder) between two or more workpieces to be welded, heating to melt the solder, and forming a connection between the same or dissimilar materials through the molten solder. Commonly used brazing methods include flame brazing, high frequency (induction) brazing, vacuum brazing, and resistance brazing.

In the tool making process, brazing is mostly used to weld harder tool heads (high-speed steel, alloys, ceramics, CBN, PCD, single crystal diamond, etc.) to relatively soft tool bodies (steel parts, alloy substrates, etc.) superior.

The basic requirements of the tool for welding are: the welding has no cracks and virtual welding, and the welding strength meets the requirements for use. Different tool materials have different requirements for the welding process. Materials such as high-speed steel, PCD, and single crystal require a lower welding temperature to avoid the impact of high welding temperature on their performance; while alloys, ceramics and other materials require a lower welding temperature. Control the stress after welding to prevent the occurrence of cracks; CBN and other materials require higher welding temperature and welding strength to ensure that the high temperature of the tool tip will not cause tooth loss when grinding instead of turning.

In recent years, with the development of tool manufacturing technology and the development and popularization of domestic vacuum welding furnaces, vacuum welding technology has been rapidly promoted and applied in the field of tool manufacturing, and has played an increasingly important role, changing the previous high-frequency welding. the vast majority of the situation.

Application Example: Carbide Hob

When the hard tooth surface is hobbed, the workpiece has high hardness, the cutting process is interrupted and the cutting layer is very thin. During the cutting process, the tool is subjected to large impact load, high cutting temperature and strong friction. Therefore, the impact toughness of the material cut by the hob is very high. In addition to the alloy blade material, hob rake angle design, and manufacturing accuracy that affect the service life of the hob, the brazing structure and brazing method of the alloy blade and the cutter body are also important.

High-frequency brazing is affected by flux, solder and human factors, and the brazing strength is lower than that of vacuum brazing, and high-frequency brazing is prone to porosity, local oxidation and uneven melting, which affects the quality of brazing. Relatively speaking, vacuum brazing can remove surface oxidation, and at the same time, the solder melts evenly, the welding quality is high, the welding accuracy is good, and the whole process can be automated.

Sometimes the brazed cemented carbide hob often occurs in the process of use, such as chipping, broken teeth, and splintering. At this time, by increasing the brazing area, improving the flatness of the brazing surface and improving the brazing material, the brazing quality can be improved.

Choice of vacuum brazing furnace:

The performance of vacuum furnaces used for welding tools has been greatly improved in recent years, and the corresponding brand parameters are also various. Therefore, it is extremely important to choose a suitable vacuum furnace.

1.Heating capacity

Heating capacity is one of the key indicators to assess whether a vacuum furnace can be used as a welding furnace. Since solder belongs to a special alloy (a new type of material formed from a variety of metal materials), it has its own melting point and physical and chemical properties. For the soldering process, there are two important temperature reference indicators, namely the solidus line of the solder itself. with the liquidus. During the soldering process, it is necessary to let the temperature rise quickly from the solidus line to above the liquidus line, so as to prevent the possibility of segregation of the solder, so as to better ensure the stability of the soldering quality. This requires the vacuum furnace to have accurate, fast and uniform heating performance.

2.Furnace cavity structure

At present, there are two types of welding furnaces: vertical and horizontal. The two structures have their own advantages: the vertical type has a larger furnace loading capacity and is easy to operate; the horizontal type has a slightly smaller furnace loading capacity, but the temperature is more uniform, and the mutual influence between the tools is smaller and the efficiency is higher. Both types of welding furnaces can meet the welding needs of most current products.

3.Brand selection

A good brand often means higher quality and better service. The RHVB-H high temperature vacuum brazing furnace produced by SIMUWU is a high-quality product for processing tool brazing process. Good temperature control accuracy and temperature control uniformity ensure the effective progress of the vacuum brazing process. With more than ten years of sales and manufacturing experience, it is exported to developed regions in Europe, America and Asia. It is a widely acclaimed vacuum furnace product.