Is the metal bonding mechanism the same as that of brazing?

Brazing is very different from pressure welding.

The word "brazing" itself represents that there are other materials other than the base metal, that is, the commonly known "brazing metal" as a third-party metal "brazing" into the weld to be welded. The brazing metal melts, and the flow fills the weld, forming an alloy layer with the base metal on both sides that have not melted at this temperature, and welding firmly.

Pressure welding is different from brazing, pressure welding (most of which are welding) does not have this third-party metal, pressure welding is the contact between two metals under a certain pressure after the two metals on the contact surface through the action of temperature, pressure, etc. to form an alloy. This process is compared to traditional fusion welding.

The changes that occur in the base metal are minimal. However, there are some pressure welding methods that also use a certain amount of brazing metal.

In general, brazing is more suitable for some thin, precise workpieces.

1. The principle of welding is different.

The principle of fusion welding: It refers to the filling material (such as welding wire) and the base material of the connection area of the workpiece are heated together to a melted state, and a molten pool is formed at the joint, and the liquid metal in the molten pool is cooled and solidified to form a firm welded joint, so that the separated workpiece is connected as a whole.

Principle of pressure welding: commonly known as solid-state welding, is a welding process that produces plastic deformation on the welded separated metal type joint surface under the action of pressure (or simultaneous heating) to make the metal connection a whole.

The principle of brazing: It is a welding method that uses the metal with a lower melting point than the welding metal as the brazing metal, heats the brazing metal together with the workpiece to the melting state of the brazing metal, and sucks it into the solid intermittent with the help of capillary action, so that the inter-diffusion, dissolution and combination of the brazing metal and the solid working surface are connected into a whole.

2. The object of welding is different.

1. Fusion welding: suitable for low-carbon steel weldments.

The heat-affected zone is narrow, less harmful, and can be used directly after welding; For carbon steel and low-alloy steel weldments, it can be normalized after welding to refine the grain and improve the mechanical properties.

2. Pressure welding: suitable for many types of weldments.

1) Spot welding is a high-speed and economical joining method.

2) Seam welding is mainly suitable for leasing and leasing for oil drums, cans, radiators, thin plate welding of aircraft and automobile fuel tanks.

3) Projection welding is mainly used for welding stamping parts of low carbon steel and low alloy steel.

4) When butt welding, the end faces of the two workpieces are in contact with each other, and they are welded along the entire contact surface after resistance heating and pressurization.

3. Brazing.

It is mainly used in instruments and conductive components that work at room temperature with little welding force. The strength of the joint of soldering is not high (<70MPa), and the tin-iron alloy brazing metal with a small amount of antimony is the most widely used.

Dissimilar metals and dissimilar materials can be welded, and there is no strict limit on the thickness difference of the workpiece; Some brazing methods can weld multiple weldments and joints at the same time, resulting in high productivity.

Fusion Welding Definition: A welding method in which the base metal to be welded is melted to form a weld.

Definition of pressure welding: A method in which pressure (heated or unheated) must be applied to the welded piece to complete the welding during the welding process.

Definition of brazing: a method in which the brazing metal and the weldment are heated together with a brazing metal with a lower melting point than the base metal, so that the brazing metal is melted (the weldment does not melt) and then wetted and filled with the gap of the base metal connection, and the brazing metal and the base metal diffuse each other to form a firm connection.

Introduction: The combustible gas used in gas welding is the same as gas cutting, mainly acetylene, liquefied petroleum gas (propane, butane, propylene, etc.) and hydrogen, etc., and oxygen is the combustible gas.

The wire used for gas welding acts as a filler metal, and when welding, it forms the weld metal together with the molten base metal. Therefore, the welding wire with the corresponding composition or performance should be selected according to the chemical composition and mechanical properties of the workpiece, and sometimes the strip cut from the welded plate can also be used as the welding wire.

When welding non-ferrous metals, cast iron and stainless steel, welding powder (flux) should also be used to eliminate the refractory oxide film and other impurities covering the surface of the welding consumables and the molten pool, and form a layer of slag on the surface of the molten pool to protect the molten metal from oxidation, eliminate gases, oxides and other impurities in the molten pool, improve the fluidity of the molten metal, make the welding smooth and ensure the quality and forming.

The essence of fusion welding is the melting and crystallization of metal, similar to the process of small casting;

The essence of pressure welding is to squeeze or squeeze out the oxides and other impurities on the joint surface through the plastic deformation of the metal to be welded, so that the pure metal is in close contact, and the atomic spacing between the interfaces reaches the normal stress range and is firmly bonded;

The essence of brazing is to use liquid brazing metal to wet the base metal, fill the joint gap, and diffuse with the base metal to achieve the connection weldment.

Brazing is joined by a third metal and is not welding in the true sense of the word. Fusion welding is the use of heat to achieve the connection.

Fusion welding: A processing method in which the workpiece to be welded is partially heated until it melts, and after condensation, a weld is formed to connect the components together. Including arc welding, gas welding, electroslag welding, electron beam welding, and soldering;

Brazing is a welding method in which the material is combined through the joint action of the wetting of the brazing metal and capillary penetration, and the brazing metal with a lower melting point than the base metal is heated to melting, but the heating temperature is lower than the melting point of the base metal, and the weld is filled with the melted brazing filler, the base metal is wetted and the base metal is diffused with each other to form an integrated welding method.

There are two main types of brazing: hard brazing and soldering. The heating temperature of hard brazing is greater than 450 degrees, the tensile strength is greater than 200 MPa, and silver-based and copper-based brazing metals are often used, which are suitable for occasions with high working stress and high ambient temperature, such as the welding of cemented carbide turning tools and geological drills.

The heating temperature of soldering is less than 450 degrees, and the tensile strength is less than 70 MPa, which is suitable for the environment with low stress and low working temperature. For example, tin-based brazing and light welding of circuits.

Brazing During the welding process, a metal material with a lower melting point than the base metal is used as the brazing metal, and the weldment and the brazing metal are heated to a temperature higher than the melting point of the brazing metal and lower than the melting point of the base metal.

What are the similarities between fusion welding, pressure welding, and brazing.

Hello, dear. Metal welding is divided into three categories: fusion welding, pressure welding and brazing according to the characteristics of its technological process. The common feature of all kinds of pressure welding methods is that pressure is applied during the welding process without the addition of filler material.

Most pressure welding methods, such as diffusion welding, high-frequency welding, cold pressure welding, etc., do not have a melting process, and there is no problem of burning of beneficial alloying elements and invading the weld like fusion welding, thus simplifying the welding process. At the same time, the heating temperature is lower than that of fusion welding, and the heating time is shorter, so the heat affected zone is smaller. Welding is a local rapid heating and cooling process, the welding area can not expand and contract freely due to the constraints of the surrounding workpiece, and welding stress and deformation will occur in the weldment after cooling.

Important products need to eliminate welding stress and correct welding deformation after welding.

Dear, hello, very cherry takako is happy to answer for you is pressure welding a metallurgical connection is electroslag pressure welding a way of welding. Electroslag pressure welding: It is to place two steel bars in a vertical or oblique direction (inclination in 4:).

1) docking form, using welding current through the gap between two steel bars, forming an arc process and an electroslag process under the flux layer, generating arc heat and resistance heat, melting steel bar, and pressurizing a pressure welding method. Electroslag pressure welding belongs to welding. The mechanical connection includes straight thread connection, cone thread connection, pier head thread connection, sleeve extrusion connection, etc.

The performance is reliable, especially suitable for the connection of thicker steel bars, and the flat ridge draft, vertical and oblique parts are suitable. At present, more than 20 steel bars are widely connected by straight threads.

Welding is the joining of two or more workpieces together.

Fusion welding is the simultaneous melting of the workpiece and the flux (electrode and wire), and the simultaneous connection pressure welding is the extrusion connection of the workpiece after it is melted.

Brazing is when the workpiece does not melt and the workpiece is joined after the flux (electrode and wire) melts.

How to distinguish fusion welding from brazing? What are the characteristics of each?

Fusion welding is characterized by the combination of atomic lead between weldments, while brazing is the use of brazing filler, an intermediate medium with a lower melting point than the weldment, to connect the weldments. The advantage of fusion welding is that the mechanical properties of the welded beam head are high, and the productivity is high when connecting thick and large parts, and the disadvantage is that the stress and deformation generated are large, and the structure changes in the heat-affected zone; The advantages of brazing are low heating temperature, smooth and smooth joints, beautiful appearance, stress deformation Xiaohuai Paizhi, the disadvantage is that the joint is low strength, and the assembly clearance requirements are high during assembly.