All kinds of brazing joints formed by ceramic metallization, because of the existence of coating or coating, restrict the use of ceramic components at high temperature. It is difficult to give full play to the superiority of high temperature stability of ceramics. It requires people to find a direct brazing method.

Direct brazing of ceramics can solve the problem of connection of parts that can not be metallized completely because of blind hole or geometric dimension factors. It can greatly simplify the brazing process and meet the requirements of high temperature use of ceramic components. This method uses brazing fillers containing Ti or Zr active elements to braze ceramics directly with metals, ceramics and ceramics, ceramics and graphite.

The development of control system for large vacuum aluminium brazing furnace is introduced. The main functions of the control system are temperature control and logical control, which require a large number of control points, and each controlled object is related to each other. The core of the control system is programmable logic controller.

The method of CX-Programmer software programming is used to control and set up various protection functions for each mechanical system. The programmable controller has the advantages of flexibility, convenience and easy maintenance.

When vacuum welding cemented carbide tools, uniform heating of tool rod and cemented carbide sheet is one of the basic conditions to ensure the welding quality. If the heating temperature of the cemented carbide sheet is higher than that of the tool rod, the strength of the joint will decrease if the melted filler metal wets the cemented carbide sheet instead of the tool rod. When the alloy sheet is sheared along the welding layer, the solder will not be destroyed, but will be detached with the alloy sheet. The milling marks on the support surface of the tool rod can also be seen on the welding layer. If the heating speed is too fast and the temperature of the tool rod is higher than that of the alloy sheet, the opposite phenomenon will occur.

Sandblasting treatment of cemented carbide. Without sandblasting equipment, the cemented carbide can be held by hand, and the oxide layer on the brazing surface and the Black Brand letters can be ground on the rotating green silicon carbide grinding wheel. If the oxide layer on the brazing surface of cemented carbide is not removed, the filler metal is not easy to wet the cemented carbide. Experience has proved that if there is oxide layer or black brand letters on the brazing surface, sandblasting treatment should be carried out. Otherwise, the brazing filler metal is not easy to wet the cemented carbide, and obvious black letters still appear in the brazing seam, which reduces the brazing area and causes the phenomenon of de-welding.

The function of brazing flux is to reduce the oxides on the tool rod and the surface of cemented carbide, so that the brazing metal can be well wetted. Generally, the melting point of filler metal is lower than that of the filler metal above 100 C, and it has better fluidity and lower viscosity. The flux melted in the brazing heating process can protect the brazing filler metal and the brazing surface, at the same time, it can reduce the oxide.

The main requirements for cemented carbide solders are as follows.

(1) The brazing filler metal should have good wettability to the brazed cemented carbide and steel matrix to ensure that the filler metal has good fluidity and permeability.

Brazing fillers for cemented carbide and steel can be divided into three categories according to melting point and brazing temperature: high temperature filler metal, normal temperature filler metal and low temperature filler metal.

Brazing temperature above 1000 °C is called high temperature brazing filler metal, such as copper and 106 brazing filler metal; brazing temperature of medium temperature brazing filler metal is between 850 and 1000 °C, such as H62 and H68 brass filler metal; low temperature brazing filler metal refers to brazing temperature between 650 and 850 °C, such as B-Ag-1 and L-Ag-49 silver-containing filler metal.

Vacuum Brazing Technology

Generally, vacuum brazing adopts stage heating mode to ensure uniform heating of workpiece. The technological parameters of vacuum brazing are as follows: setting temperature 620 C, holding 15 min-30 min, vacuum degree 3 x 10-3 PA and heating rate 10 C/min in the brazing temperature control meter. In the initial cooling stage, the brazing temperature is controlled at 10 C/min, ending at 450 C, and then cooling to room temperature with the furnace.

Sharp tools make good work! Product quality is always the basis of enterprise survival. We can not only provide customers with high quality and stable performance of vacuum furnace products, but also employ senior technicians with many years of experience in the use of vacuum furnace, which can provide users with good process support in the use of vacuum furnace. This Studio provides vacuum brazing process and technology to solve all kinds of abnormal problems in the production process. It can help users to improve the qualified rate of products. Provide vacuum furnace and its spare parts.

1. The main body of spraying is circular structure. Passivation treatment on the surface ensures a beautiful appearance and better recovery effect of solder. It can effectively prevent the accumulation of solder in spraying chamber and is very convenient to clean up. The circular structure adopts a real high-pressure fan with a pressure of 280 mbar and a special air nozzle with a wind speed of 50-200 m/s, which can effectively remove the residual solder on the surface.

2. The spray mixing system contains many humanized designs. The flux recovery drum is equipped with impurity filtration, which can filter most of Tiexu.

Brazing technology is a method of filling joint gap by wetting liquid brazing filler metal and diffusing with base metal to achieve joints by using materials with lower melting point than base metal as brazing filler metal and heating them to temperatures higher than the melting point but lower than the melting point of base metal (so that base metal remains solid).

Classification of brazing methods

The quality of brazing joint is related to the brazing method, brazing material (flux, filler metal, etc.) and process parameters. According to different characteristics and standards, brazing methods have the following classification methods.