FDA
FDA 21 CFR 1040.10 - Laser Product Performance Standards
Yi-Chun LinPh.D.Taiwan
Laser Materials ProcessingPublished
Dec 16, 2025
Magnesium Laser Cleaning
When laser cleaning magnesium, I've found it works best to start with lower power settings, as its lightweight nature and high reflectivity set it apart from denser metals like steel. This allows quick contaminant removal without much heat buildup, but always monitor closely to avoid surface melting at the end.
Laser-Material Interaction
Absorption Coefficient
1.1e7
m⁻¹
5.9e5
1.1e7
9.9e7
Absorptivity
0.12
0.02
0.12
0.6
Laser Damage Threshold
0.15
J/cm²
0.27
0.15
1.6e4
Reflectivity
0.74
dimensionless (ratio)
0.35
0.74
1
Thermal Destruction Point
923
K
133
923
3,865
Thermal Shock Resistance
1.8
W/m
6.7
1.8
3.8e5
Vapor Pressure
36.1
Pa
0
36.1
1.1e5
Thermal Destruction
923
K
256
923
3,859
Specific Heat
1,023
J/kg·K
43.4
1,023
1,905
Laser Reflectivity
0.94
0.4
0.94
73.5
Thermal Conductivity
156
W/m·K
7.4
156
450
Thermal Expansion
2.5e-5
K^{-1}
4e-6
2.5e-5
31.7
Laser Absorption
0.06
0.02
0.06
4.2e8
Thermal Diffusivity
8.8e-5
m²/s
2e-6
8.8e-5
0
Ablation Threshold
1.8
J/cm²
0.09
1.8
4.3
Magnesium Laser Cleaning Material Characteristics
Electrical Conductivity
2.2e7
S/m
6.6e5
2.2e7
6.6e7
Electrical Resistivity
4.5e-8
Ω·m
0
4.5e-8
2e-6
Fracture Toughness
23
MPa√m
0.67
23
157
Surface Roughness
1.6
μm
0.02
1.6
6.6
Youngs Modulus
45
GPa
10.4
45
2e11
Oxidation Resistance
0.81
-554
0.81
1,762
Density
1,738
kg/m³
1.7
1,738
9,408
Hardness
38
HV
0.2
38
3,500
Corrosion Resistance
-2.4
V
-1.1
-2.4
1.1e6
Compressive Strength
160
MPa
8
160
2,625
Flexural Strength
170
MPa
11.4
170
2,897
Tensile Strength
160
MPa
3
160
3,000
Porosity
0
fraction
0
0
15
Absorptivity
0.09
0.02
0.09
0.6
Boiling Point
1,363
K
929
1,363
6,454
Absorption Coefficient
5.9e7
m^{-1}
5.9e5
5.9e7
9.9e7
Melting Point
923
K
133
923
3,865
Vapor Pressure
398
Pa
0
398
1.1e5
Thermal Destruction Point
923
K
133
923
3,865
Reflectivity
0.92
0.35
0.92
1
Thermal Shock Resistance
52
K
6.7
52
3.8e5
Laser Damage Threshold
1.2
J/cm²
0.27
1.2
1.6e4
Thermal Destruction
923
K
256
923
3,859
Specific Heat
1,023
J/kg·K
43.4
1,023
1,905
Laser Reflectivity
0.94
0.4
0.94
73.5
Thermal Conductivity
156
W/m·K
7.4
156
450
Thermal Expansion
2.5e-5
K^{-1}
4e-6
2.5e-5
31.7
Laser Absorption
0.06
0.02
0.06
4.2e8
Thermal Diffusivity
8.8e-5
m²/s
2e-6
8.8e-5
0
Ablation Threshold
1.8
J/cm²
0.09
1.8
4.3
Magnesium surface magnification
Before Treatment
When examining the magnesium surface before laser cleaning at 1000x magnification, we see a rough texture covered in scattered dark patches. Grime and oxide layers cling tightly to the uneven contours, blocking any hint of the underlying metal. These contaminants create a mottled appearance that obscures the material's natural form.
After Treatment
After the laser treatment, the same surface reveals a smooth and even finish under 1000x view. All the grime lifts away cleanly, exposing a bright and uniform gleam
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
Magnesium Laser Cleaning Laser Cleaning FAQs
Q: What are the specific laser settings and parameters for cleaning magnesium alloys without causing damage?
A: 10ns pulses prevent thermal damage. For cleaning magnesium alloys, use a 1064 nm wavelength with 10 ns pulses at 1.2 J/cm² fluence. Specifically, keep the repetition rate at 50 kHz and scan speed at 500 mm/s to avoid thermal damage. Thus, these parameters ablate oxides effectively while preserving substrate integrity.
Q: How do you safely remove oxide layers and corrosion from magnesium surfaces using laser cleaning?
A: Argon shielding prevents re-oxidation. In the removal of magnesium oxide, we utilize 1064 nm wavelength lasers at 1.2 J/cm² fluence. Specifically, this ablates MgO selectively without harming the base metal. Thus, an inert argon gas shield during the 500 mm/s scan prevents immediate re-oxidation, delivering a pristine, corrosion-free surface.
Q: What special safety precautions are needed when laser cleaning magnesium due to fire risk?
A: Requires inert gas shielding. Mandatory inert gas shielding, particularly at the 1064 nm wavelength, prevents magnesium ignition. Thus, keep fluence below 1.2 J/cm² to avoid excessive heat input. Employ robust fume extraction for highly reactive MgO particles, which pose explosion risks.
Q: Can laser cleaning be used to prepare magnesium surfaces for welding or coating applications?
A: removes oxides without thermal damage. Using a 1064 nm wavelength at 1.2 J/cm² fluence, laser cleaning effectively prepares magnesium surfaces. Specifically, this approach removes oxides without thermal damage, thus yielding an ideal surface profile for enhanced coating adhesion and robust welds, notably in aerospace and medical fields.
Q: What are the challenges with laser cleaning cast magnesium alloys versus wrought forms?
A: Porosity requires fluence <1.2 J/cm². Notably, cast magnesium alloys pose greater challenges from their inherent porosity, which can trap contaminants and thus requires careful fluence control below ~1.2 J/cm² to avoid subsurface damage. Their varied surface texture, particularly compared to wrought forms, demands more precise parameter tuning.
Q: How effective is laser cleaning for removing contaminants like oils and lubricants from magnesium parts?
A: Vaporizes oils without residue. Laser cleaning, specifically employing a 1064nm wavelength and 1.2 J/cm² fluence, effectively removes organic oils from magnesium surfaces. Notably, this method vaporizes contaminants without chemical residue, thus serving as a superior, eco-friendly alternative to solvent-based approaches for precision parts.
Q: Does laser cleaning affect the fatigue strength or mechanical properties of magnesium components?
A: Preserves fatigue strength integrity. When laser cleaning is properly configured at 1.2 J/cm² fluence, it particularly preserves magnesium's structural integrity. Notably, the 10 ns pulse width limits thermal input, thus avoiding micro-cracking and notable shifts in fatigue strength to sustain component longevity.
Q: What is the best way to validate the success of magnesium laser cleaning?
A: Confirm oxide removal integrity. Validate magnesium laser cleaning through microscopic inspection and surface roughness measurement. Particularly, confirm complete oxide removal while preserving base material integrity, thus ensuring parameters like 1.2 J/cm² fluence avoid inducing thermal damage.
Q: Why is magnesium considered more difficult to laser clean than aluminum or steel?
A: Magnesium's low melting point (~650°C) and high reactivity particularly require precise laser parameters. Specifically, we must control fluence around 1.2 J/cm² to remove oxides without melting the substrate—a far narrower window than for steel or aluminum. Thus, meticulous tuning ensures damage-free outcomes.
Q: What type of laser (fiber, pulsed, continuous wave) works best for magnesium cleaning applications?
A: For cleaning magnesium surfaces, pulsed fiber lasers at 1064 nm prove particularly optimal. Specifically, employing a fluence of 1.2 J/cm² alongside a 10 ns pulse width minimizes thermal input, thus preventing harm to the delicate substrate. Scanning at 500 mm/s then delivers efficient, uniform oxide layer removal.
