Resistance welding technology

WELTAC®

Elements for resistance element welding for modern multi-material car body design.

 

Flexible joining of lightweight materials

The WELTAC® resistance element welding enables the joining of lightweight materials with steel of all qualities.

The classical joining technologies, for example resistance spot welding, cannot be used in the material mix of today’s car bodies, since the materials are not or only limited thermally compatible. In order to fulfil these requirements, Böllhoff has developed the WELTAC® technology.

This product is made by Böllhoff

Method / principle

Resistance element welding is a further development of resistance spot welding.
Compared to the conventional procedure, a rivet-like resistance element is used as the auxiliary joining part made of a material which is compatible with the base sheet. In the first process stage, the punching of the WELTAC® welding element occurs in the upper material layer(s). Afterwards this component is welded to the lower steel material layer(s) in the second stage of the process.

Applications

The main field of application for WELTAC® is the automotive industry – in the body construction.

Product benefits
  • High-strength joints
  • Use of existing, conventional spot-welding equipment in the body construction shop possible
  • Wide application range regarding material qualities and thicknesses (aluminium and steel), incl. press-hardened steel

Product benefits

There are many good reasons for using our products.

Strength and options.
Point by point.

Different multi-material designs can be flexibly combined

Lightweight materials, like i.e. aluminium, sandwich materials and polymeric materials can be easily joined with steel of all qualities.

High-strength joints

WELTAC® is a flexible technology with high demands on joint strength.

Processing with a proven system

In the first process stage, the WELTAC® Automation is based on the proven electric-hydraulic processing system RIVSET® Automation EH.

Use of existsing equipment

Already existing resistance spot welding systems of modern car body constructions can be used for the second WELTAC® process stage.

Detailed description

 

How does resistance element welding work?

In the first process stage, a rivet-like resistance element, used as the auxiliary joining part made of a material compatible with the base sheet, will be punched in the upper material layer (i.e. aluminium). Afterwards this component is welded to the lower steel material layer in the second stage of the process.

 

1. Process stage: punching-in the element

WELTAC® resistance element welding in the 2-step process – 1. Process stage: punching-in the element

1. Process stage of the WELTAC® resistance element welding: punching-in the element

 

2. Process stage: welding

WELTAC<sup>®</sup> resistance element welding in the 2-step process – 2. Process stage: welding

2. Process stage: welding

Böllhoff only supplies the WELTAC® elements and the WELTAC® Automation of the first process stage.

Product variants

For the full variety of applications, we offer a selection of different welding elements.

WELTAC® elements differ in head and shaft geometry, surface, shaft length and shaft diameter: We have the right welding element for your application.

Field of application (sheet thickness) 0,8 – 1,2 mm

Flat head shape / low mechanical load

Field of application (sheet thickness) 0,8 – 1,2 mm

High head shape / high mechanical load

Field of application (sheet thickness) 1,3 – 1,7 mm

Reinforced head and shaft part / increased mechanical load

Field of application (sheet thickness) 1,8 – 2,2 mm

Reinforced head and shaft part / increased mechanical load

Field of application (sheet thickness) 2,3 – 2,7 mm

Increased reinforcement in head and shaft part / maximum mechanical load

Field of application (sheet thickness) 2,8 – 3,2 mm

Increased reinforcement in head and shaft part / maximum mechanical load

Downloads

Find out more: related downloads.

If you would like to know more, simply download the relevant brochures.

Title Language Version File Download
WELTAC®
Resistance element welding for modern multi-material car body design
English 05/2019 2636 kB / PDF
English 05/2019 2636 kb / PDF

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