Laser Marking Brass Guide：Analysis of difficulties and recommended solutions

Brass is widely used in hardware fittings, bathroom products, musical instruments, electronic components, nameplates, decorative crafts, jewelry, valves, and mechanical parts due to its excellent electrical conductivity, corrosion resistance, and good machinability.With the continuous growth of industrial marking and customization demand, more and more customers are asking:

Is Fiber Laser Engraving Brass feasible?

What is the performance of Laser Marking Brass?

Which laser engraving machine should be used for brass processing?

Based on more than ten years of experience in the laser marking industry, ZS Machinery provides a comprehensive analysis of brass laser marking and engraving technology from the perspectives of material properties, processing challenges, equipment recommendations, and parameter suggestions. We first begin with the material characteristics of brass and the difficulties in laser engraving.

I. Core Challenges of Laser Processing Brass: Material Limitations

The high reflectivity and high thermal conductivity of copper-based materials (especially pure copper and brass) are the primary obstacles in laser marking, mainly reflected in the following aspects:

1. Low Laser Energy Absorption Efficiency

Brass has a reflectivity of over 80% for mid-infrared lasers (such as 1064nm fiber lasers), meaning most of the laser energy is reflected rather than absorbed. This results in insufficient effective energy acting on the material surface.

If the energy is too low → no clear marking can be formed.

If the power is too high → surface overheating, oxidation, or deformation may occur.

2. Rapid Heat Conduction and Poor Energy Localization

The thermal conductivity of brass is approximately 401 W/(m·K), more than five times that of iron.

During laser irradiation:

Heat spreads rapidly to surrounding areas

It is difficult to reach localized melting or vaporization temperature

Marking lines may become blurry and inconsistent in depth

This is especially obvious in fine marking such as QR codes or small text

3. Surface Sensitivity

Brass surfaces are prone to oxidation, forming oxide layers such as CuO and Cu₂O. The laser absorption characteristics of these oxide layers differ significantly from pure brass, leading to:

Inconsistent marking quality between batches

Surface roughness affecting energy absorption uniformity

Contamination such as oil or dirt further reducing stability

II. Process Parameter Adjustment Challenges

Laser marking quality (clarity, depth, contrast) depends on the coordination of multiple parameters. The unique properties of brass significantly increase the difficulty of process optimization.

1. Balance Between Power and Speed

Insufficient power → shallow marking, easy to erase, or no marking at all

Excessive power → excessive melting, burrs, burn marks, or deformation

Too fast speed → insufficient energy deposition, unclear marking

Too slow speed → excessive heat accumulation, surface damage

Therefore, when laser engraving brass, repeated testing is required to find the “critical energy window.” Different grades of copper alloys (such as T2 copper and H62 brass) show significant parameter differences.

2. Influence of Spot Size and Frequency

Brass marking typically requires:

Small spot size → higher energy density

High frequency (≥100 kHz) → reduced thermal diffusion

However, this also introduces challenges:

Small spot size requires extremely precise focusing; slight defocus causes significant energy loss

High-frequency operation requires matching scan speed to avoid striping or uneven marking

High-frequency operation may increase equipment wear

3. Difficulty in Contrast Enhancement

Brass has a natural golden color. If marking relies only on surface melting or vaporization, the contrast is often limited, especially on polished surfaces.

Common enhancement methods include:

Oxidation coloring

Microstructure modification

However, oxidation is highly temperature-sensitive:

Insufficient temperature → thin oxide layer, low contrast

Excessive temperature → overly thick or peeling oxide layer, resulting in blur

Additional processes such as nitrogen protection or post-treatment (e.g., passivation) are often required, further increasing process complexity.

III. High Requirements for Laser Equipment Performance

The difficulty of brass marking places strict requirements on laser system hardware, mainly in the following aspects:

1. Laser Source Selection

Different wavelengths show significantly different absorption rates on brass:

1064nm fiber laser

Low cost

Low absorption efficiency

Typically requires ≥50W power for stable processing

532nm green laser

Higher absorption (2–3× that of 1064nm)

Better processing stability

Higher cost (2–5× same-power fiber laser systems)

355nm UV laser

Highest precision

Minimal thermal effect

Shallow marking depth, suitable for fine surface marking

2. Scanning Galvo and Focusing System

Brass marking requires:

High scanning speed (to reduce thermal accumulation)

High stability (to prevent beam drift)

High-transmittance optical lenses (e.g., quartz materials)

Focus tolerance strictly controlled within ±0.1 mm

Otherwise, it may cause:

Energy fluctuation

Uneven marking quality

3. Cooling System Requirements

During long-term high-power laser operation:

Efficient water cooling system is required

Flow rate ≥ 2 L/min

Temperature fluctuation ≤ 5°C

Otherwise:

Laser power instability

Reduced marking consistency

4. Gas Protection System (Optional but Recommended)

Introducing nitrogen or inert gas during marking can:

Reduce surface oxidation of brass (preventing color inconsistency caused by uneven oxide layers)

Suppress plasma formation (plasma generated during laser-material interaction may reflect laser energy and reduce efficiency)

IV. Special Application Challenges

Different applications impose significantly different requirements on brass marking, further increasing process complexity:

1. Precision Electronics (e.g., copper terminals, connectors)

No burrs required

Depth ≤ 0.01 mm

Must not affect electrical conductivity

Requires extremely precise heat control

2. Decorative and Identification Applications

High contrast required

Fine patterns (e.g., logos, serial numbers)

Balance between aesthetics and surface integrity

3. Wear-Resistant Industrial Applications

Marking depth ≥ 0.05 mm

Long-term durability required

Must solve thermal deformation issues during deep engraving

V. ZS Machinery Recommended Solutions

1. Standard Industrial Marking Solution (Cost-Effectiveness Prioritized)

For general standard industrial brass marking, we recommend a 50W fiber laser marking machine. It is suitable for:

copper hardware, nameplates, and general markings.

The machine uses a 1064nm fiber laser (power 50W-200W recommended)

High-speed galvanometer system (≥8000mm/s)

Optimized pulse frequency (50–120kHz range)

Small spot fine focusing configuration

This configuration is recommended because it is stable, reliable, low-cost, and suitable for mass production.

2. High-Quality, High-Precision Fine Marking Solution

For high-precision brass marking, we recommend a UV laser marking machine. It is suitable for: electronic components, precision marking microstructure processing, decorative processes, etc.

The machine is equipped with a 355nm ultraviolet laser system, a precision galvanometer, and a highly stable cooling system. It features precise spot control (micrometer level). Its characteristics include virtually no heat-affected zone and high precision, but it is also more expensive.

3. Marking solutions for thin or small parts

For marking small workpieces, we recommend using a high-precision fixture (positioning error ≤ 0.02mm) to avoid workpiece displacement during marking. The fixture should also have thermal conductivity (e.g., using copper alloy material) to aid heat dissipation and prevent workpiece deformation from affecting subsequent processing.

For batch marking scenarios, we recommend using a vision system combined with a conveyor belt to improve marking efficiency.

Conclusion

The core challenges of laser marking on brass (also known as Fiber Laser Engraving on Brass) stem from its high reflectivity, high thermal conductivity, and sensitivity to surface oxidation.

These challenges result in brass marking equipment being slightly more expensive than equipment for marking ordinary metals. This is because higher power or additional configurations are required.

If you are unsure which marking system is suitable for your product, please feel free to contact us, and we can recommend the most appropriate system for your application.