What is brazing?

metal welding is divided into fusion welding and brazing.

During fusion welding, the materials to be welded, including welding wire, are melted and solidified, so that the two materials are integrated. Common electric welding, gas welding and argon arc welding belong to fusion sea.

During brazing, the welded metal does not melt, but the welding material (welding wire) melts and adheres to the welded material closely, and is connected by the force between atoms of the two materials. Common soldering, brazing and lead lining are all brazing.

what is brazing? How many types are there?

brazing technology is a method that uses a material with a lower melting point than the base metal as the brazing filler metal, heats the weldment and the brazing filler metal to a temperature higher than the melting point of the brazing filler metal but lower than the melting temperature of the base metal (so that the base metal is still in a solid state), fills the joint gap with the wetting effect of the liquid brazing filler metal, and diffuses with the base metal to realize the connection of the welded workpiece.

classification of brazing methods

the quality of brazed joints is related to the selected brazing method, brazing materials (flux, solder, etc.) and process parameters. According to different characteristics and standards, brazing methods can be classified as follows.

① According to the melting point of the used solder, it can be divided into soldering and brazing. When the melting point of the solder is lower than 45℃, it is called soldering, and when it is higher than 45℃, it is called brazing.

② According to the brazing temperature, it can be divided into high temperature brazing, medium temperature brazing and low temperature brazing, and the temperature division is relative to the melting point of the base metal. For example, for steel parts, heating temperature above 8℃ is called high temperature brazing, heating temperature between 55 ~ 8℃ is called medium temperature brazing, and heating temperature below 55℃ is called low temperature brazing; However, for aluminum alloys, the heating temperature above 45℃ is called high temperature brazing, the temperature between 3 ~ 45℃ is called medium temperature brazing, and the heating temperature below 3℃ is called low temperature brazing.

③ According to different types of heat sources and heating methods, it can be divided into flame brazing, furnace brazing, induction brazing, resistance brazing, immersion brazing, gas phase brazing, soldering iron brazing and ultrasonic brazing.

④ According to the way of removing oxide film on the surface of base metal, it can be divided into flux brazing, flux-free brazing, self-flux brazing, gas shielded brazing and vacuum brazing.

⑤ according to the characteristics of joint formation, it can be divided into capillary brazing and non-capillary brazing. The situation that liquid solder fills the brazing seam by capillary action is called capillary brazing; Non-capillary brazing is called when capillary action does not play a major role in the formation of brazed joints. Contact reactive brazing and diffusion brazing are the most typical non-capillary brazing processes.

⑥ According to the different base materials or solders to be connected, it can be divided into aluminum brazing, stainless steel brazing, titanium alloy brazing, high-temperature alloy brazing, ceramic brazing, composite material brazing, silver brazing and copper brazing.

what is brazing? What are the brazing methods?

Brazing is a method to connect weldments by using a metal material with a melting point lower than that of the base metal as the brazing filler metal, heating the weldments and the brazing filler metal to be higher than the melting point of the brazing filler metal and lower than the melting temperature of the base metal, wetting the base metal with liquid brazing filler metal, filling the joint gap and diffusing with the base metal.

the brazing methods include: high frequency induction brazing, flame brazing, resistance brazing, furnace brazing, phase brazing, soldering iron brazing, ultrasonic brazing, etc.

what and what brazing

metal welding is divided into fusion welding and brazing.

During fusion welding, the materials to be welded, including welding wire, are melted and solidified, so that the two materials are integrated. Common electric welding, gas welding and argon arc welding belong to fusion welding.

During brazing, the welded metal does not melt, but the welding material (welding wire) melts and adheres to the welded material closely, and is connected by the force between atoms of the two materials. Common soldering, brazing and lead lining are all brazing.

What is the principle of brazing

Brazing

soldering and brazing

A welding method in which a metal material with a melting point lower than that of the base metal is used as a brazing filler metal, and the base metal is wetted with a liquid brazing material, and the interface gap of the workpiece is filled, so that the base metal and the base metal are diffused mutually. The brazing deformation is small, and the joint is smooth and beautiful. It is suitable for welding precise, complex and components made of different materials, such as honeycomb structure plates, turbine blades, cemented carbide tools and printed circuit boards. Before brazing, the workpiece must be carefully processed and strictly cleaned to remove oil stains and excessive oxide film, and ensure the assembly clearance of the interface. The clearance is generally required to be between .1 and .1 mm..

what is gas phase brazing

brazing brazing and brazing is a welding method in which a metal material with a melting point lower than that of the base metal is used as a brazing filler metal, and the base metal is wetted with a liquid brazing filler metal, and the interface gap between the workpiece and the base metal is filled, so that the base metal and the base metal are diffused mutually. The brazing deformation is small, and the joint is smooth and beautiful. It is suitable for welding precise, complex and components made of different materials, such as honeycomb structure plates, turbine blades, cemented carbide tools and printed circuit boards. Before brazing, the workpiece must be carefully processed and strictly cleaned to remove oil stains and excessive oxide film, and ensure the assembly clearance of the interface. The clearance is generally required to be between .1 and .1 mm.. Types According to different welding temperatures, brazing can be divided into two categories. Welding heating temperature below 45℃ is called soldering, and above 45℃ is called brazing. Soft soldering is mostly used for welding conductive, airtight and watertight devices in electronics and food industry. Tin welding with tin-lead alloy as filler metal is the most commonly used. Soft solder generally needs flux to remove oxide film and improve the wettability of solder. There are many kinds of flux, and rosin alcohol solution is often used for soldering in electronic industry. The residue after welding of this flux has no corrosive effect on the workpiece, which is called non-corrosive flux. The flux used for welding copper, iron and other materials consists of zinc chloride, ammonium chloride and vaseline. When welding aluminum, fluoride and fluoroborate should be used as flux, and hydrochloric acid plus zinc chloride should be used as flux. The residue of these fluxes after welding has corrosive effect, which is called corrosive flux and must be cleaned after welding. Brazed joints have high strength, and some can work at high temperature. There are many kinds of brazing filler metals, among which aluminum, silver, copper, manganese and nickel are the most widely used. Aluminum-based solder is often used for brazing aluminum products. Silver-based and copper-based solders are often used for brazing copper and iron parts. Manganese-based and nickel-based solders are mostly used to weld parts such as stainless steel, heat-resistant steel and superalloy that work at high temperature. Brazing materials such as palladium-based, zirconium-based and titanium-based are commonly used for welding refractory metals such as beryllium, titanium and zirconium, graphite and ceramics. When selecting solder, the characteristics of base metal and the requirements for joint performance should be considered. Brazing flux is usually composed of chlorides and fluorides of alkali metals and heavy metals, or borax, boric acid and fluoroborate, and can be made into powder, paste and liquid. Lithium, boron and phosphorus are also added to some solders to enhance their ability to remove oxide film and wet. The flux residue after welding is cleaned with warm water, citric acid or oxalic acid. Methods There are many commonly used brazing processes, which are mainly distinguished according to the equipment used and the working principle. According to the heat source, there are infrared, electron beam, laser, plasma, glow discharge brazing, etc. According to the working process, there are contact reaction brazing and diffusion brazing. Contact reactive brazing is to use the liquid phase generated by the reaction between solder and base metal to fill the joint gap. Diffusion brazing is to increase the diffusion time of heat preservation, so that the weld and the base metal are fully homogenized, so as to obtain the joint with the same performance as the base metal. Soldering iron soldering is used for soldering small, simple or very thin parts. Wave soldering is used for the assembly and welding of large quantities of printed circuit boards and electronic components. When welding, the molten solder at about 25℃ forms a peak through a narrow gap under the pressure of the pump, and the workpiece is welded through the peak. This method has high productivity and can realize automatic production on the assembly line. Flame brazing uses the flame of combustible gas mixed with oxygen or compressed air as the heat source for welding. Flame brazing equipment is simple and easy to operate. According to the shape of the workpiece, multiple flames can be heated and welded at the same time. This method is suitable for welding medium and small parts such as bicycle frame and aluminum kettle mouth. Immersion brazing The workpiece is partially or wholly immersed in a solder bath covered with flux or a salt bath with only molten salt for heating and welding. This method has the advantages of uniform heating, rapid heating and accurate temperature control, and is suitable for mass production and welding of large components. The salt in the salt bath is mostly composed of flux. After welding, a large amount of flux often remains on the workpiece, and the cleaning workload is heavy. Induction brazing is a welding method that uses high frequency, medium frequency or power frequency induction current as heat source. High frequency heating is suitable for welding thin-walled pipe fittings. Coaxial cable and split induction coil can be used for brazing in the field far away from power supply, which is especially suitable for welding some large components, such as pipe joints that need to be disassembled on rockets. Brazing in the furnace: The workpiece assembled with brazing filler metal is put in the furnace for heating and welding, and brazing filler metal is often needed, and it can also be protected by reducing gas or inert gas, so that the heating is relatively uniform. Continuous furnace can be used in mass production. The vacuum brazing workpiece is heated in a vacuum chamber, which is mainly used for welding products requiring high quality and oxidizable materials.

what is brazing, how to weld it and what equipment is needed?

Brazing refers to a welding method in which a metal material with a melting point lower than that of the base metal is used as a brazing filler metal, and the base metal is wetted with a liquid brazing filler metal, and the interface gap of the workpiece is filled and diffused with the base metal. The brazing deformation is small, and the joint is smooth and beautiful. It is suitable for welding precise, complex and components made of different materials, such as honeycomb structure plates, turbine blades, cemented carbide tools and printed circuit boards. Before brazing, the workpiece must be carefully processed and strictly cleaned to remove oil stains and excessive oxide film, and ensure the assembly clearance of the interface. The clearance is generally required to be between .1 and .1 mm..

equipment: WE53 special liquefied gas porous spray gun, or induction welding machine, or traditional oxygen acetylene heating equipment and furnace.

what is silver brazing?

silver brazing is a brazing process in which silver solder is used as the material.