Thermal conductivity welding

Laser welding technology

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Table of Contents

  • Principle of Fiber laser welding
  • Features of Fiber laser welding
  • Application of Fiber laser welding
  • Prospects for Fiber laser welding

Laser processing technology uses the characteristics of the interaction between the laser beam and the substance to Metal) is a technology for cutting, welding, surface treatment, etc. If the laser beam follows a certain time And the energy value, projected onto the material to be processed, instantaneously obtaining high energy on the surface of the material, and its organization
The structure and performance are changed to achieve the purpose of processing. Laser processing technology mainly includes laser welding Connection(Laser Welding Machine), laser surface treatment, laser drilling, laser cutting, laser rapid prototyping, laser sintering synthesis function
Ceramic material technology, laser membrane technology, laser micromachining, laser preparation of nanomaterial technology, laser gas Facies deposition and so on.

Laser processing technology has the characteristics of high efficiency, high precision, high quality, wide application range, energy saving and environmental protection, etc.
And can realize flexible processing and ultra-fine processing. In automobile manufacturing, steel metallurgy, microelectronics, aviation, machine
Machinery manufacturing, textile industry, chemical industry, construction and shipbuilding industry have been widely used, some
Industries (such as the automotive and microelectronics industries) have reached a high level

Principle of Fiber laser welding

Laser welding can be realized by continuous or pulsed laser beam. The principle of laser welding can be divided into thermal
Conductive welding and laser deep penetration welding. The power density is less than 104-105W/cm2 for heat conduction welding, at this time
The penetration depth is shallow and the welding speed is slow; when the power density is greater than 105-107W/cm2, the metal surface is heated
It is recessed into a "cavity" to form a deep penetration welding, which has the characteristics of fast welding speed and large aspect ratio.

Heat conduction welding: the surface of the workpiece to be processed is heated by the laser beam radiation, the surface temperature rises, and the heat Conduction causes the surface to be heated to a certain depth at a certain depth, and under certain laser process parameters (such as laser power, pulse Width, etc.) to obtain a specific molten pool, through the movement of the laser beam, to achieve the purpose of welding the workpiece. Laser deep penetration welding: When the laser power density reaches a certain value, the surface material of the workpiece to be processed will vaporize The temperature inside the small hole that has absorbed the laser energy is very high, causing the surrounding metal to melt. Outside the hole wall The liquid flow and the surface tension of the wall layer are maintained in a dynamic balance with the continuously generated vapor pressure in the cavity. The small hole moves with the movement of the laser beam, and the liquid metal flows in the opposite direction to fill the leftover after the small hole is removed. Voids and cool to form a weld.

Thermal conductivity welding

Features of Fiber laser welding

Features of fiber laser welding machine advantage:

(1) Laser welding is a non-contact welding process, and the loss and deformation of equipment can be minimized.

(2) The welding seam is narrow, the penetration ratio is large, the heat affected zone of the welded joint is small, and the deformation of the workpiece after welding is small.

(3) It does not need to be carried out under vacuum conditions, and the welding is not affected by the magnetic field. (Compared to electron beam welding)

(4) The laser beam can be focused to a small area, which is suitable for welding small parts.

(5) A wide range of weldable materials can realize the welding of difficult-to-weld metals and can be used for welding of dissimilar metals.

(6) Large flexibility, easy to realize high-speed automatic welding, etc.

Fiber laser welding machine Disadvantages:

(1) The laser and welding system parts are expensive, and the initial investment cost is high.
(2) The focused spot of laser welding is small, so the assembly precision of the workpiece joint is higher.
(3) The absorption rate of the solid material to the laser is low, and the energy conversion rate is low, less than 10%. Schematic diagram of laser wire filler welding
(4) Plasma may be generated during welding, which affects welding quality.

Laser arc hybrid welding

With the development of industrial lasers and the in-depth research of welding technology by scientific researchers, laser welding technology It has been applied in many fields. However, due to the high cost and maintenance cost of laser welding equipment, Enough laser welding is widely used, mostly in mass production or large-scale parts welding industries, such as automotive industry Industry, shipbuilding, etc., or some special fields with large investment, such as aerospace industry, nuclear energy industry, etc.

Application of Fiber laser welding

Laser welding must be used in the automotive field

It is reported that the use of laser tailor-welded blank technology can reduce the original more than 20 sets of forming molds to 4-8 sets. Schematic diagram of the production process of 20X20m deck members. Laser plate splicing welding in the shipyard The material utilization rate is increased from 40% to 65%, and the processing efficiency is high, and the scrap rate is low.

Laser tailor-welded blank technology
Laser welding of welding door of a sub-assembly
Laser welding of welding door of a sub-assembly
Frame laser welding
Frame laser welding
Laser welding of top cover and side wall
Laser welding of top cover and side wall
Follow-up welding laser welding
Follow-up welding laser welding

The application of handheld fiber laser welding machine in automobile manufacturing began with gear welding of transmissions. Due to the use of laser welding, the gears after welding have almost no welding deformation, no post-weld heat treatment is required, and the welding speed is greatly improved, so it is quickly applied. Laser welding has been widely used in the production of auto parts abroad, including exhaust pipes, mufflers, transmission gears, clutch gears, automobile air conditioning pulleys, shock absorber oil storage cylinder barrels.

Laser welding vehicle gear

(b) Application in shipbuilding industry
①Welding processing of large flat workpieces made by high-quality laser single-sided welding without turning over;
②The manufactured flat plate is smooth, flat and has little thermal deformation, so the leveling and repair work is omitted, making the subsequent welding of the profile easier;

Shipyard got laser flat panel welding

(c) Handheld laser welding Application in aerospace
①Replace traditional riveting technology with laser welding;
②The main components (blades, combustion chamber, etc.) of the aero-engine are welded by laser welding;
③Laser welding is used for the repair of aero engine parts.

Application of laser welding in aerospace

(d) laser welding aluminum Application in other areas

Other applications of laser welding

Prospects for Fiber laser welding