A Study on the Influence of Laser Welding Process Parameters on Weld Quality

The core parameters of laser power, scanning speed, and focal length directly affect the quality of the weld.By adjusting the power range, you can avoid burning through the workpiece or failing to fuse the materials. By controlling the speed of movement, you can obtain a continuous, uniform weld. By adjusting the focal point, you can control the distribution of energy.By optimizing parameters and using protective gas, the density and mechanical properties of the weld can be significantly improved. When used in practice, the thickness of the material and the type of joint must be taken into consideration.

Why do welding parameters directly affect the quality of the finished product?

Laser welding may sound high-tech, but in fact it is no different from controlling the heat of a wok.If the power is too great, it can burn through the metal, and if it's too weak, the weld won't be strong enough.Recently, several of our clients have told us that the equipment they bought has a wide range of parameters, but that they still get holes or cracks in the welds.The key is that the parameters have to be combined with the precision of Lego blocks.

The golden mean of laser power.

Power is like a car's accelerator. It's not the case that the more you have the better.When testing with 0.8-mm stainless steel, the power was increased from 800W to 1200W, resulting in a 40 % increase in penetration, but when the power was increased to 1300W, honeycomb-shaped pores appeared.He suggests that beginners start at 80 % of the recommended equipment value and gradually adjust the settings, just as one would adjust the brightness of a mobile phone.

Scanning speed is an art.

Have you ever seen how a pastry chef pipes whipped cream? If the welding gun moves too quickly, the weld will have a discontinuous, scale-like appearance.There's a little trick: Listen to the "hiss" of the welding. A steady, continuous sound means the speed is right.For welding thin sheets, it is safer to keep the speed in the range of 8-12 mm / s.

The hidden skills of out of focus photography.

This parameter is often overlooked, but in fact it is just like focusing a single-lens reflex camera.Positive defocusing concentrates the energy, making it suitable for deep penetration welding. Negative defocusing, on the other hand, creates a smaller heat-affected zone, making it more suitable for precision components.I remember the last time I was helping a parts manufacturer calibrate its equipment. When I adjusted the focal length from + 2 mm to - 1 mm, the width of the weld seam shrank by 0.3 mm.

A gas shield.

Don't underestimate the importance of the argon cover, which is far more important than sun-block.If the flow of protective gas is inadequate, the weld will oxidize, turning the metal a rusty color.If the flow is too high, it can disturb the molten pool, so 15-20 L / min is recommended.Once, he forgot to connect the air tube, and the result was an abstract art piece.

It's a game of arranging combinations of parameters.

Finding the optimal parameters is like playing with a Rubik's Cube, and requires systematic testing.He suggested that they conduct a parameter matrix experiment in which they would fix two variables and adjust the third, and then record the shape of the weld, the depth of penetration, and the presence of bubbles.Recently, he used the orthogonal experiment method to help a medical device company optimize its parameters, raising the rate of good products from 72 % to 93 %, and the factory manager was almost ready to give a bonus to the welding machine.