Laser Treatment Technology: Development and Application

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  What matters before you add a laser step
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  What laser treatment technology does to a machined surface
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  Choosing the laser type for the material in front of you
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  Where laser treatment technology fits a CNC routing
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  Distortion, depth and the marks that fail
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  How we run a laser step inside a CNC order
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  Laser type against material and job

Laser treatment technology uses a focused beam to alter a surface without touching it. On metals, the beam heats a thin layer, melts it locally, or vaporizes it. Depth is controlled by pulse energy and dwell time, not by tool pressure. That is why it works on thin walls and finished faces where a cutter would leave marks or deflect the part.

For most job-shop work the task is simple. We mark a part number, a revision letter, a serial number, a logo or a traceability code. In other jobs the laser is functional: stripping a coating off a bonding pad, roughening a surface for adhesive, or burning away contamination before welding.

There is a limit worth stating plainly. A laser changes the surface; it does not create a precision feature. If a slot needs ±0.005 mm, the mill cuts it. The laser can label it afterward. Treat the two operations as separate steps with separate tolerances, and the routing stays clean.

Depth is where most assumptions break. A fiber laser mark on 304 stainless is often 5–30 μm deep. That is enough to survive bead blasting in some setups and not in others. If the mark has to survive a full anodize or a tumble, say so before the process starts, because that decision changes the parameters.

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  MarkingReadable contrast, minimal material removal
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  EngravingDeeper cut for touch-feel or wear resistance
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  Surface prepCoating removal, cleaning, bonding texture
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  Heat treatmentLocal hardening or annealing on selected zones

Fiber lasers at 1064 nm are the default for metals. They mark stainless, aluminum, steel, titanium, copper and brass without a coating. Power in the 20–50 W range handles most marking and light engraving. Going higher buys speed, not detail. For deep engraving on tool steel or 17-4PH, 50–100 W saves time but needs better fume extraction.

UV lasers at 355 nm are the choice for plastics, anodized aluminum and thin coatings. The shorter wavelength breaks bonds instead of melting, so the heat-affected zone stays small. ABS, PC, POM and PEEK can be marked without the raised, melted edge a fiber laser leaves. Anodized aluminum comes out as a clean white or dark mark depending on the layer.

CO2 lasers at 10.6 μm suit organics and some ceramics and coatings. They cut and engrave acrylic, wood, and certain painted surfaces. On bare metal they mostly reflect, so they are the wrong tool unless a coating is present to absorb the energy.

Pick by material first, then by feature size. A 0.2 mm character on black anodized aluminum is a UV job. A 6 mm part number on a bead-blasted steel bracket is a fiber job. Both are routine, and both need the drawing to say what the mark must survive.

Aerospace and medical work benefits most from traceability. A laser-etched lot code survives cleaning, passivation and sterilization cycles that would erase ink. On 316L and titanium instruments, we mark after machining and before final inspection so the mark is verified with the part.

Automotive and EV parts often need a durable identifier on a casting or a bracket. Laser marking handles ADC12 aluminum die castings and 6061 housings without a primer. Because it is a non-contact process, it also works on parts that are already coated or painted, removing only the top layer.

Robotics and electronics use laser work for function, not just labels. Stripping solder mask, exposing a pad, or texturing a surface for adhesive all happen before assembly. These jobs need a process window, not just a logo file, so send a sample with the coating specified.

Industrial machinery and new energy parts tend to be large. Our 4,000 mm maximum processing size covers most frames and plates, and the laser step runs after machining so the mark references the final datum, not a rough one.

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  Mark after anodizingColour anodize changes the mark contrast
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  Mark before passivationOn stainless, passivation does not remove a laser mark
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  Deburr firstA raised burr distorts the focal distance

Heat input is the main failure mode. A long pulse at high average power puts energy into the part, and thin walls or small bosses can move. The fix is short pulses, low average power and a few passes instead of one heavy pass. On a 0.8 mm aluminum wall, that difference decides whether the part stays flat.

Depth is often over-requested. A mark that is 50 μm deep is not twice as durable as one at 25 μm; it is slower and puts more heat in. For most traceability marks, 10–20 μm survives normal handling, cleaning and light abrasion. For touch-feel engraving on a control panel, deeper is fine because the part is thick.

Contrast is a separate variable from depth. On stainless, a fiber laser can produce a dark mark or a light mark by changing the pulse overlap. On anodized aluminum, the mark removes the dye layer and shows the substrate. Neither is better; the drawing should say which one is wanted.

The marks that fail in the field usually fail for one of three reasons: the process was run before a finish that covered or removed it, the character height was under 1.5 mm, or the mark was placed on a surface that later got machined. All three are routing mistakes, not equipment mistakes.