Laser Marking Application Case: Deep Engraving on Aluminum and Aluminum Alloys
Laser Marking Application Case: Deep Engraving on Aluminum and Aluminum Alloys
Equipment Configuration: Chuangxin MFP-50W Fiber Laser
Deep engraving on aluminum is different from both stainless steel and carbon steel—aluminum is soft, has a low melting point (660°C), and conducts heat extremely quickly, making it prone to slag accumulation and edge burrs during engraving. However, the good news is that because aluminum is soft, a 50W laser can achieve decent depth results.
I. Deep Engraving Principle
Aluminum deep engraving relies on laser layer-by-layer material removal. The challenges with aluminum are:
- Low melting point (660°C): Prone to melting rather than vaporization, producing slag
- Extremely fast thermal conductivity (237 W/m·K): Heat dissipates rapidly, requiring higher energy density
- High reflectivity: Some laser energy is reflected, reducing efficiency
Coping strategies:
- Use high power density (high power + small spot size)
- Auxiliary air blowing is critical (removes slag, cools the processing area)
- Multiple shallow engraving passes are better than a few deep passes
II. Equipment Configuration
| Item | Parameter |
| Laser Source | Chuangxin MFP-50W Acousto-Optic Q-Switched Pulsed Fiber Laser |
| Wavelength | 1064nm |
| Single Pulse Energy | 1-1.5 mJ |
| Cooling Method | Air-cooled |
III. Parameter Reference
Recommended Starting Parameters
| Parameter | Recommended Value | Notes |
| Power | 70-90% | Aluminum conducts heat quickly, requiring high power |
| Speed | 200-400 mm/s | Slow speed ensures energy accumulation |
| Frequency | 20-30 kHz | Low frequency increases single-pulse energy |
| Hatch Spacing | 0.05-0.08mm | Deep engraving hatch does not need to be too dense |
| Fill Method | Bidirectional fill | Bidirectional fill can reduce slag accumulation |
| Number of Passes | 5-20 | Layer-by-layer engraving |
Depth and Passes Reference
| Target Depth | Reference Passes | Notes |
| 0.1mm | 3-5 | Shallow engraving, suitable for logos |
| 0.3mm | 8-15 | Medium depth |
| 0.5mm | 15-25 | Pay attention to air blowing and cooling |
| 1.0mm | 40-60 | Lower efficiency, recommended to process in multiple sessions |
Comparison with stainless steel: Although aluminum is soft, its fast thermal conductivity and tendency to melt mean that engraving speed is not much faster than on stainless steel. The 50W model requires about 8-15 passes to engrave 0.3mm on aluminum, similar to stainless steel.
IV. Key Technical Points
1. Air Blowing is Essential
If slag generated during aluminum deep engraving is not promptly removed, it will re-solidify at the groove bottom and edges, forming burrs. Compressed air or nitrogen at 0.4-0.6MPa is strongly recommended, directed at the processing area from the side.
2. Layered Engraving
Control each layer to 0.03-0.05mm; do not overdo it. Aluminum’s fast thermal conductivity means that engraving too deep in one pass will cause heat to spread over a large area, melting the surrounding region as well.
3. Back-Reflection Protection
Aluminum is a highly reflective material, and a significant amount of laser energy can be reflected back to the laser source. The Chuangxin MFP series has built-in isolators, but during long-term high-power deep engraving, it is recommended to regularly check the laser source’s operating condition.
4. Special Characteristics of Die-Cast Aluminum
Die-cast aluminum is porous inside, and bubbles or voids may appear during deep engraving. Recommendations:
- Test engraving first to confirm material density
- Slow down the speed to avoid exposing internal pores
V. Effect Characteristics
- Depth: 0.1-0.5mm, practical range
- Bottom Texture: Matte, may have slight slag traces
- Edges: Requires air blowing to maintain sharpness
- Color: Light gray to dark gray
- Wear Resistance: Good, but aluminum itself is soft, and deep marks may wear over time
VI. Precautions
- 50W aluminum deep engraving limit: Efficiency drops significantly above 0.5mm; for depths above 1mm, 70W/100W is recommended
- Thin aluminum sheet deformation: Aluminum sheets below 1mm are prone to heat accumulation and deformation during deep engraving; use heat dissipation fixtures
- Air blowing direction: Adjust the air blowing direction properly to avoid blowing slag onto already processed areas
- Do not deep engrave anodized aluminum: The anodized layer is very thin (5-25μm); deep engraving will completely destroy the oxide layer, resulting in a poor appearance
- Post-processing: Aluminum deep engraving may leave burrs on the edges; simple finishing with fine sandpaper or a file can be done
- Aluminum alloy mold numbers
- Aluminum nameplate deep engraving
- Mechanical aluminum part permanent identification
- Aluminum profile coding marks
- Industrial aluminum component identification
VII. Application Scenarios
Summary: The 50W model can achieve practical depths of 0.3-0.5mm for deep engraving on aluminum, but the key lies in air blowing and layered engraving strategies. Aluminum is soft but conducts heat quickly, and the slag generated during engraving is the main challenge to address. If the customer only needs shallow engraving (0.1mm level), 3-5 passes are sufficient with good efficiency.
*Different aluminum alloys (6061, 7075, die-cast aluminum, etc.) have significantly different engraving results. It is recommended to create samples first.*
