Laser cutting speed and metal cutting quality
Cutting speed is often inversely proportional to the quality of the laser cutter. That is to say there is an optimum range of cutting speed which can be confirmed by the equipment specification or experiment. Besides that, the cutting speed is required to be adjusted according to the differences of the material properties such as thickness, the material, melting point and thermal conductivity as well as the surface tension after melting.
The effects of cutting speed on quality of the cutting are as follows.
- Increasing the cutting speed properly can improve the incision quality. That is to say, the incision will be a little narrower, the incision surface will be flatter and this adjustment also can reduce the deformation.
- Overly-fast cutting speed will cause two problems that the line energy of the cutting cannot reach the required energy and large drag because the melted melt cannot be brought away by the jet flow quickly. And the result is incision quality reduced due to the slag hanging on the incision.
- Overly-low cutting speed can cause many slags and rounded fillets. The fact is that the cutting line is the anode of the plasma arc. In order to ensure the stability of the electric arc, the anode region or anode spot will find the media to conduct electricity in the cut near the arc and transfer more heat by the radial direction of the jet flow. Meanwhile, this phenomenon will widen the incision, and then the melted material ash from both sides will converge on the bottom and curdle to slags which are uneasy to clean. Additionally, the upper edge of the incision will be rounded off because it is melted too much.
- Extremely low velocity will bring about wider incision which even causes the flameout of the voltaic arc.
In conclusion, the cutting quality will be affected by the cutting speed to a large extent. What we need to do most is to find the optimum balance point between speed and quality and operate carefully in reality to multiply the machines' value.