FDA
FDA 21 CFR 1040.10 - Laser Product Performance Standards
Todd DunningMAUnited States
Optical Materials for Laser SystemsPublished
Dec 16, 2025
Cerium Laser Cleaning
When laser cleaning cerium, watch out for its relative softness that can cause surface deformation, though its strong reflectivity limits heat penetration and restores precision in optical components
Laser-Material Interaction
Absorptivity
0.62
0.25
0.62
0.6
Thermal Destruction
1,071
K
273
1,071
3,520
Laser Reflectivity
0.92
0.4
0.92
0.94
Thermal Expansion
6.3e-6
K^{-1}
6e-6
6.3e-6
26.2
Thermal Conductivity
11.3
W/m·K
10.4
11.3
17.5
Specific Heat
192
J/(kg·K)
113
192
457
Ablation Threshold
1.5
J/cm²
0.65
1.5
2.9
Absorption Coefficient
1.2e7
m^{-1}
3e5
1.2e7
6.6e7
Laser Damage Threshold
1.8
J/cm²
1.1
1.8
3.3
Thermal Diffusivity
8.7e-6
m²/s
7e-6
8.7e-6
1.9e-5
Cerium Laser Cleaning Material Characteristics
Density
6.8
g/cm³
4.3
6.8
8.8
Oxidation Resistance
-2.5
V
0
-2.5
149
Youngs Modulus
33
GPa
15.8
33
63.5
Hardness
27
HV
0.38
27
906
Boiling Point
3,716
K
1,705
3,716
3,834
Absorptivity
0.42
0.25
0.42
0.6
Thermal Destruction
1,071
K
273
1,071
3,520
Laser Reflectivity
0.92
0.4
0.92
0.94
Thermal Expansion
6.3e-6
K^{-1}
6e-6
6.3e-6
26.2
Thermal Conductivity
11.3
W/m·K
10.4
11.3
17.5
Specific Heat
192
J/(kg·K)
113
192
457
Ablation Threshold
1.5
J/cm²
0.65
1.5
2.9
Absorption Coefficient
1.2e7
m^{-1}
3e5
1.2e7
6.6e7
Cerium surface magnification
Before Treatment
The contaminated surface appears rough and uneven under magnification. Irregular deposits cover much of the metal, hiding its natural features. Scattered debris clings tightly, creating a dull and patchy overall look.
After Treatment
Laser treatment restores a smooth and uniform surface free of residues. The metal now shows clear grain patterns without any clinging particles. A consistent shine emerges, revealing the underlying clean texture.
Regulatory Standards & Compliance
ANSI
ANSI Z136.1 - Safe Use of Lasers
IEC
IEC 60825 - Safety of Laser Products
OSHA
OSHA 29 CFR 1926.95 - Personal Protective Equipment
Cerium Laser Cleaning Laser Cleaning FAQs
Q: Why does cerium oxide create bright white sparks during laser cleaning, and is this dangerous?
A: Pyrophoric nature causes combustion. Those bright white sparks arise from cerium's pyrophoric properties, where fine particles basically combust on contact with oxygen once heated by your 1064 nm laser. This reaction is pretty hazardous, demanding strong fume extraction and spark containment systems—especially given the low ablation threshold of just 1.2 J/cm².
Q: What is the safest laser parameter (wavelength, power, pulse width) for cleaning cerium or cerium-coated surfaces without damaging the substrate?
A: 1064nm low fluence nanosecond pulses. For cerium's thermal sensitivity, stick with a 1064nm wavelength and fluence under 1.2 J/cm² to avoid melting. Typically, nanosecond pulses near 10ns keep oxidation risks low below 150°C. Start testing at 50μm spot size with 500mm/s scan speed, checking surface integrity after each pass.
Q: How do you effectively remove cerium oxide slurry/polishing compound residues from optical surfaces with a laser without leaving a hazy film?
A: Two-step fluence prevents hazing. Typically, begin with a low fluence pass below 1.2 J/cm² to gently dislodge the bulk residue, then follow with one at ~5.1 J/cm² to remove the tenacious film. Basically, this two-step approach prevents laser-induced hazing by managing thermal input.
Q: What are the specific health risks from the fumes and nanoparticles generated when laser cleaning cerium, and what type of filtration is required?
A: Requires HEPA/ULPA filtration respirators. When laser cleaning cerium, it basically produces highly toxic nanoparticles that demand HEPA/ULPA filtration with spark arrestance, particularly due to its fairly low 1068K melting point. Operators typically require fitted respirators, since the 50 µm spot size at 5.1 J/cm² generates respirable cerium oxide fumes.
Q: Can a fiber laser safely and effectively clean a cerium-infused thermal barrier coating from a turbine blade?
A: Requires fluence below 5.1 J/cm². With cerium's pretty low ablation threshold of 1.2 J/cm², a fiber laser at 1064 nm can basically selectively remove the infused coating. Keeping fluence fairly below 5.1 J/cm² proves critical to avoid damaging the underlying nickel superalloy substrate.
Q: Why is cerium sometimes added to alloys or coatings specifically to make them *more difficult* to laser clean?
A: Cerium typically forms a pretty stable CeO₂ layer with an ablation threshold around 1.2 J/cm². This tough oxide remains highly reflective and resists thermal breakdown well, demanding higher laser fluence—often over 5 J/cm²—for effective removal versus other metals.
Q: What is the best method for laser cleaning cerium-contaminated tools or components from the glass polishing industry?
A: 1064nm laser 5.1 J/cm². For cerium-contaminated tools, apply a 1064nm laser at 5.1 J/cm² fluence. This basically ablates the dried slurry quite effectively, while fairly minimizing heat transfer to substrates like aluminum or plastics to avoid surface damage.
Q: Does laser cleaning alter the catalytic properties of a cerium oxide (CeO2) catalyst substrate?
A: Alters oxygen vacancy concentration. Yes, laser cleaning can fairly alter catalytic properties in a big way. That 5.1 J/cm² fluence typically reduces CeO₂ to Ce₂O₃ while inducing surface roughening. Such phase and morphological shifts basically affect oxygen vacancy concentration, which remains pretty critical for the material's catalytic activity.
Q: How do you prevent the re-deposition of vaporized cerium onto adjacent clean areas during the laser cleaning process?
A: Nitrogen jet evacuates vapor plume. We basically deploy a nitrogen assist gas jet at 45° to actively sweep away the cerium vapor plume and prevent re-deposition. That's pretty critical, considering cerium's high IR absorption and low 1.2 J/cm² ablation threshold. Directing scans away from cleaned areas also helps cut down cross-contamination on adjacent surfaces.
Q: Is wet laser cleaning or dry laser cleaning more effective for removing thick layers of cerium oxide scale?
A: Dry ablation removes tenacious oxide. Dry laser cleaning at 5.1 J/cm² proves superior for thick cerium oxide scale. Basically, the direct ablation mechanism efficiently removes that tenacious oxide layer, while plasma confinement in wet methods can be fairly less effective against such significant, hard (270 HV) deposits. This approach ensures complete scale removal with excellent post-process cleanliness.
Cerium Laser Cleaning Dataset Download
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