Laser Cutting

Process Definition & Working Principle

Laser cutting is a thermal, non-contact material separation process where the energy source is a highly concentrated, coherent, monochromatic, and collimated beam of electromagnetic radiation. The acronym "LASER" stands for Light Amplification by Stimulated Emission of Radiation. The physical principle relies on focusing the laser beam onto the workpiece surface, causing a localized temperature rise exceeding the melting, vaporization, or ignition point of the target material.

The laser beam interacts with the material surface, where photons are absorbed by free electrons in the metallic lattice (a phenomenon described as inverse bremsstrahlung absorption). This absorption transfers kinetic energy to the lattice, manifesting as a rapid temperature spike. The heat conduction process is mathematically modeled using Rosenthal's moving line heat source equation:

Kinematics, Axes, & Machine Configuration

The kinematics of CNC laser cutting machines are defined by the ISO 841 standard, which establishes a right-handed Cartesian coordinate system. The primary linear axes are structured as follows:

• Z-axis: Governs the vertical movement of the cutting head along the optical axis, perpendicular to the sheet. Positive displacement (+Z) moves the head away from the workpiece surface.
• X-axis: The longest horizontal axis, representing the longitudinal travel of the gantry.
• Y-axis: The horizontal axis representing the transverse movement of the cutting head carriage along the gantry beam.

Machine configurations are classified into three primary kinematic designs: