Thermo mechanical class of diffusion bonding in machining
Combined types connect small parts, if it is impossible to create a high-quality seam in other ways. The thermo mechanical class includes the following types of diffusion bonding in machining:
- Blacksmith
- Contact
- Diffusion
Forge diffusion bonding in machining
This method was common to join iron blanks long before the invention of modern diffusion classes. The work pieces heat in a forge, put one on top of the other, and fastened with hammer blows. The mechanized subspecies, when the work pieces are squeezed by a press, is called press diffusion.
The quality of the connection depends on the experience of the master. The list of metals that is easy to weld by this method limits to those with good ductility. Due to low productivity and low reliability of the connection, forging type of diffusion bonding in machining is rarely common.
What is contact diffusion?
The metal heats by a current passing through the place of contact between the work pieces, then compressed or upset. This type is easy; therefore it is widely common at enterprises of the machine-building industry as part of robotic complexes.
Depending on the tasks to solve, the contact type of diffusion performs as:
- Pinpoint, clamping the parts between the electrodes.
- After the current applies, a point connection forms at the point of squeezing.
- Butt with heating of the entire contact area.
- Embossed with preliminary application of protrusions on the planes to connect.
- After the current is applied, the reliefs are deformed, the surface levels.
- Suture, when the parts overlap with roller electrodes.
What is the procedure of diffusion?
The technology comes on the mutual penetration of atoms of materials, if we press them against one another. When heated, the rate of particle exchange increases. Diffusion bonding in machining carries out in a vacuum chamber or in an inert gas environment.
The parts compress with a force of at least 20 MPa, the surface layers get heat with an electric current to a temperature close to the melting point. For reliable adhesion, the work pieces leave in this position for a while, without turning off the current.
These types of diffusion are performed using the energy of friction, explosion, pressure, and ultrasound. When exposed to heat, sufficient heat generates to melt the material.
What is friction diffusion?
The technology includes in the list of promising developments. One of the blanks to join fixes motionless, the other, pressed against it, rotates. A detailed classification of diffusion bonding in machining especially friction diffusion includes the following subspecies:
- With stirring, it comes on equipment equipped with a rotation tool with two elements - a base and a tip.
- The connection creates by extrusion followed by stirring.
- The pipes radially join by placing a rotating ring between the ends.
- The pin is repaired with small through damage.
- Linear is performed without rotation. The work pieces rub against each other.
- In the inertial form of diffusion, the work pieces move due to the energy of the previously untwisted flywheel.
What is cold diffusion?
The technology comes on the principle of compression of parts by punches with a force of 1 - 3 GPa. Diffusion bonding in machining is carried out with rods, steam rollers. The punch is pressed into the work piece until plastic deformation forms, which contributes to the appearance of interatomic bonds and the creation of a connection between the parts.
Moreover, diffusion is performed by simple squeezing or shearing of the parts after squeezing. The strength of the connection depends on the quality of preparation of the joint, the degree of compression, the nature of the impact.
When joining end-to-end, the amount of deformation is limited by the size of the parts of the work pieces protruding from the clamps. To prevent the sheets from warping when overlapping, they are fine with clamps.
What is semi-automatic diffusion?
As a process, semi-automatic diffusion like diffusion bonding in machining is a method of joining metal in which the wire of an electrode is fed at either variable or constant speed to the weld point. In parallel with this, an inert or active gas also supplies there, which protects the base metal and the heated electrode from ambient air currents.
In the course of the case, using a semiautomatic diffusion machine, an excellent quality of the joint ensures. Plus, it is much easier to ignite the arc, the speed increases, and the percentage of convenience in performing work, since the welder does not need to constantly change electrodes and clean the seams from accumulated slags.
A semi-automatic diffusion machine is an electromechanical type device designed to make metals using a consumable electrode and feed it to the diffusion site.
What are the types of semi-automatic diffusion?
As such, there are a large number of semiautomatic devices on the market. So before you buy something, it will not be superfluous to understand all the nuances. As a convenient alternative TO diffusion bonding in machining, a classification according to the method of protecting the weld pool against oxidation processes propose.
On this basis, the following types of semi-automatic diffusion are there:
- Under the flux layer
- In protective gases
- Work with flux-cored wire
What is the division of semi-automatic machines?
Semi-automatic machines themselves divide into:
- Single body,where the control system, diffusion power source and wire feeder are common in one body.
- Complex design, which includes two or more parts. Usually, in such devices, the main control and the mechanism with the torch are located in one block, and the additional control with the diffusion power source is in another.
Summary diffusion bonding in machining
In addition, do not forget that the diffusion machine can be household, professional and semi-professional. And here there is a significant difference not only in power characteristics, but also in price.
So, when choosing equipment, determine the range of work to do. It is likely that for your ideas it will be advisable to use an inverter semiautomatic diffusion machine, since it is versatile and much more convenient to use.
