Laser joining

Summary

This video explores the fundamentals of laser joining, focusing on laser welding and laser brazing. It discusses heat conduction and deep penetration welding processes, highlighting the role of laser intensity in weld depth. The video details how plasma formation aids energy absorption, enhancing welding efficiency. Applications in automotive manufacturing are showcased, particularly in creating tailored blanks and polymer joining. The distinct characteristics of welding versus soldering are explained, along with advancements in joining materials, including potential future applications for glass and biomaterials. Overall, it emphasizes the precision and efficiency of laser technology in modern manufacturing.

Takeaways

• 😀 Laser joining consists of laser welding and laser brazing/soldering.
• 😀 Laser welding can be categorized into heat conduction welding and deep penetration welding.
• 😀 Heat conduction welding relies on thermal diffusion to create a melt pool, resulting in a symmetrical joint.
• 😀 Deep penetration welding utilizes high laser intensity to vaporize material and create a plasma channel, allowing for deeper welds.
• 😀 Laser welding is efficient due to minimal lateral heat diffusion, reducing distortion compared to traditional methods.
• 😀 The stability of the melt pool during laser welding is maintained by a balance of gas pressure, liquid pressure, inertia, and curvature pressure.
• 😀 Laser brazing does not melt the base materials, instead using a lower melting point filler to create strong joints.
• 😀 Applications of laser joining are prevalent in the automotive industry, including tailored blanks and aluminum welding.
• 😀 The process can be tailored for specific materials, such as using different wavelengths for transparent polymers.
• 😀 Future developments in laser joining may include new materials, like glass and biomaterials, utilizing advanced laser techniques.

Q & A

What are the two main processes involved in laser joining?

The two main processes are laser welding and laser brazing (or soldering).

How does laser welding operate fundamentally?

Laser welding involves focusing laser radiation onto a material to absorb energy, which is then converted into heat to melt the material and join two parts together.

What is the difference between heat conduction welding and deep penetration welding?

Heat conduction welding involves melting material primarily through heat diffusion, while deep penetration welding creates a capillary effect that allows for more intense, localized heating and vaporization.

What happens to the penetration depth as laser intensity increases?

Initially, penetration depth increases linearly with laser intensity until a critical threshold is reached, after which it experiences a steep increase followed by a more gradual rise.

What is a key characteristic of the melt pool in deep penetration welding?

In deep penetration welding, a keyhole forms in the melt pool, allowing for large aspect ratios and efficient energy coupling with minimal lateral heat diffusion.

What role does plasma play in the laser welding process?

Plasma forms from the vaporized material, creating a pressure that affects the stability of the capillary and enhances energy absorption from the laser.

How can laser welding be optimized for different materials?

By tailoring the absorption characteristics of the materials, such as using transparent materials for the laser while making the joining partner absorbent, efficient energy transfer can be achieved.

What distinguishes laser brazing from laser welding?

In laser brazing, the base materials do not melt; instead, a lower melting-point filler material is used to join the components without melting the base materials.

What applications utilize laser welding and brazing in the automotive industry?

Laser welding and brazing are widely used in automotive applications, including the assembly of body panels and structural components for their strength and efficiency.

What future developments are mentioned for laser joining technologies?

Future developments may include the joining of advanced materials like glass and biomaterials using ultra-fast lasers and novel absorption mechanisms.