CMT Welding in Metal Fabrication and How Is It Similar to MIG Welding?

We explore the differences of MIG Welding (Metal Inert Gas) and CMT Welding (Cold Metal Transfer) and how it is used in metal fabrication process.

What is Welding?

Welding can be defined as a metal fabrication process that utilises high heat to melt and join materials, commonly metals or thermoplastics together. In other words, it is basically a joining process that involve the manipulation of material phase from solid to liquid and back to solid. Welding technology has long been and is constantly evolving. It is no surprise that nowadays there are numerous welding methods currently being applied in the industry.

MIG Welding in Metal Fabrication

In MIG Welding, the workpiece and the welding gun are part of the same electrical circuit. The electrode wire is automatically fed through the gun. Current instantaneously flow the moment the electrode wire touches the workpiece. As the electrode wire rapidly heats up due to the high amperage, the tip of the solid electrode begins to melt into metal droplets.

The metal droplets would then separate from the electrode forming an electrical arc that is around 3500°C which heats up and melts the workpiece forming a molten puddle. This enable the metal droplets to fuse with the base metal. As the temperature decreases, the molten puddle of base material and metal droplets solidify, forming weld beads. This process continuously repeats itself several times each second until the seams are fully welded.

CMT Welding in Metal Fabrication

The differences in CMT and MIG welding process is fairly subtle with the exception in the way the electrode wire is fed.

In contrast to continuously feeding the electrode wire into the molten puddle (MIG), in CMT, the electrode wire is instantly retracted the moment current flows. This provides the welding some time to cool before each drop is placed. In doing so, this process leaves a smooth weld that is way stronger than the hotter weld (MIG).

These steps are repeated throughout the welding process. Obviously, this requires a lot of sophisticated control technology which is why it is commonly performed using a welding robot.

Enabling the welding some time to cool means that this welding process can be carried out at a lower temperature. Thus, reducing the risks of heat-related defects from occurring in the welded materials. Through the usage of robotic arms and advanced control system, welding can be carried out at high-speed precision and consistency.

Why use CMT Welding in Metal Fabrication?

There are tremendous advantages in opting to use CMT for your products that include:

  • The ability of CMT to weld materials at a lower temperature can be leveraged to mitigate heat-related defects such as, material warpage and the oil-canning effect.
  • Works well with thin metals that are prone to warping.
  • Allows the welding of dissimilar metals (eg: steel and aluminium) through its controlled metal disposition and low heat-input.
  • Automated process, means greater speed, precision and consistency in products.
CMT Welding in Metal Fabrication

Contact us today to find out more

We also offer in-house design and fabrication services for welding fixtures and jigs to optimize the process lead-time and efficiency. Contact our experts today to discuss on how we can help you.

About Demand Options Sdn Bhd

Demand Options was established in 1997 and currently has a suite of metal fabrication capabilities, including laser cutting and metal stamping processeses and secondary processes like welding, powder coating, and assembly services. Demand Options is a subsidiary of Ge-Shen Corporation Berhad.

About Ge-Shen Corporation Berhad

Ge-Shen Corporation Berhad (www.gscorp.com.my) is a contract manufacturer that specializes in plastic injection moulding, sheet metal fabrication and assembly services in 3 locations across South East Asia. GSCORP has years of experience helping product owners bring their ideas to life. Ge-Shen Corporation Berhad is listed on the main market of Bursa Malaysia Securities Berhad.