Solutions to Common Problems in Welding High-Reflectivity Metals

In order to overcome the problems of energy reflection, insufficient melt depth, and equipment damage that arise when welding highly reflective metals, researchers have improved the combination of power and speed parameters, used pulse-mode control to reduce splatter, and strengthened pre-welding surface treatment (cleaning / coating) to improve weld quality.At the same time, we emphasize the maintenance and protection of lenses and the selection of protective gases to help operators reduce production costs and extend the life of equipment.

Why is it so difficult to weld highly reflective metals?

Highly reflective metals such as copper, aluminum, and stainless steel are easily "reflected" by the laser beam, resulting in shallow weld penetration, spattering, and even damage to the laser optics.The problem is that the material's surface has a high reflectivity.

Parameter adjustment and optimization.

Power and speed are in sync.

Don't rush to turn up the power; first try to slow down the welding speed, so that the laser energy can be more fully absorbed by the material.For example, when welding a 1-mm-thick aluminum plate, a combination of 2,000 watts of power and a speed of 1.2 m / min is more stable than 3,000 watts of power and a speed of 2 m / min.

The secret of the pulse frequency.

Highly reflective materials are more suitable for the pulse mode.Keeping the frequency in the 50-200 Hz range can reduce spatter while ensuring a stable melt pool.Remember to adjust the peak power setting in accordance with the thickness of the metal. Thin sheets require high frequency but low peak power, while the reverse is true of thicker sheets.

Preparation of the materials is also an essential step in the process.

The surface must be thoroughly cleaned.

Oxidation and oil are the unseen killers of welding.After wiping with acetone, and then using a steel brush for mechanical polishing, the reflectivity of the aluminum surface can be reduced by 30 %.

Coating techniques have many uses.

Coating a metal surface with graphite or titanium dioxide is like giving a laser a "power absorber.In particular, when welding copper, a thin layer of carbon powder can double the energy absorption rate.

Maintenance and repair.

Don't be lazy when checking your lenses.

Check the focus and collimation mirrors at least once a week.If you find that your lenses have been damaged, replace them immediately. The reflected light produced by high-reflectance materials is particularly damaging to lenses.

The right gas must be selected.

Although helium is more expensive, it is more suitable for high reflectivity welding.It has a higher ionization energy, which can effectively suppress plasma interference.If you're on a tight budget, try a 3: 7 mixture of argon and helium.