1. Mirror Metal Materials

1.1 Definition

Metal and alloy materials whose surfaces are specially processed to exhibit high reflectivity (typically ≥80%), low surface roughness (Ra ≤0.05 μm), and a mirror-like imaging appearance.

1.2 Key Surface Indicators

Reflectivity: Strong ability to reflect visible light; high-quality mirror metals can achieve reflectivity above 90%, comparable to glass mirrors.

Roughness: Extremely smooth surface, with Ra (arithmetical mean deviation of the profile) ≤0.05 μm; some high-precision products can reach below 0.01 μm, with no visible scratches, pits, or surface defects.

1.3 Visual Characteristics

Capable of producing clear reflections of objects and colors. Unlike ordinary metals, mirror-finish metals are processed to minimize surface roughness, enabling predominantly specular reflection and resulting in a true mirror effect.

1.4 Materials

Base Material: The substrate is metal or alloy without a specific material restriction. As long as the reflectivity and roughness meet the required standards, the material can be classified as a mirror-finish metal.

2. Mirror Metal Processing — Impact on Laser Equipment

2.1 Reflectivity

Laser Lens Damage / Attenuation:

Mirror-finish metals have extremely high reflectivity (≥80%), which means a large portion of the laser beam is reflected back toward the laser head. If the focusing lens is repeatedly exposed to reflected laser energy and heat, its coating may burn or peel off, and the lens itself may crack. This results in decreased focusing precision, reduced laser intensity, and degraded processing quality (e.g., uneven cutting edges or blurry engraving).

Laser Tube / Generator Overload and Damage:

Reflected laser light may re-enter the laser source (such as a CO₂ laser tube or fiber laser generator), disrupting the internal energy oscillation balance. This accelerates the aging of reflective coatings inside the tube, causes abnormal internal discharge, and shortens the lifespan of the laser tube. In severe cases, it can directly lead to generator burnout.

2.2 Processing Angle

When engraving or cutting mirror metal vertically, the risk of laser reflection is highest. Tilting the material or adjusting the laser incident angle can reduce but not eliminate reflection hazards. Proper angle control, along with protective measures (e.g., anti-reflection coatings or shielding devices), is strongly recommended when processing mirror-finish metals.