Materials Suitable for Laser Welding
Laser welding machines are highly versatile and can join a wide range of materials, particularly metals with high melting points, thermal conductivity, or oxidation sensitivity. Below is a classification of commonly welded materials:
1. Metals
(1) Steels
Carbon Steel: Low- and medium-carbon steels weld well; high-carbon steels require preheating to avoid cracks.
Stainless Steel: Austenitic (e.g., 304, 316), martensitic (e.g., 410), and ferritic grades are weldable, but heat input must be controlled to prevent corrosion.
Alloy Steel: Tool steels and mold steels (may require post-weld heat treatment).
(2) Aluminum & Aluminum Alloys
Pure aluminum and alloys (e.g., 6061, 5052) can be welded, but their high reflectivity demands high-power or pulsed lasers with shielding gas (e.g., argon).
(3) Copper & Copper Alloys
Pure copper, brass, and bronze have high thermal conductivity, requiring high-power lasers (e.g., fiber lasers) or green/infrared lasers to reduce reflectivity.
(4) Titanium & Titanium Alloys
Aerospace-grade alloys (e.g., Ti-6Al-4V) need strict inert gas shielding (e.g., argon) to prevent oxidation.
(5) Nickel-Based Alloys
Inconel, Hastelloy, etc., are weldable but require precise heat control to avoid cracking.
(6) Others
Magnesium alloys, tungsten, and molybdenum are possible but challenging.
2. Dissimilar Metal Combinations
Some combinations (e.g., copper-aluminum, steel-aluminum) can be welded, but issues may arise:
Thermal expansion mismatch → stress cracks.
Brittle intermetallic compounds (e.g., Fe-Al).
3. Materials Unsuitable for Laser Welding
Highly reflective metals: Gold, silver (require specialized lasers).
Thermosensitive materials: Thin plastics may deform.
Incompatible dissimilar pairs: E.g., direct Al-Fe welding forms brittle phases.
Key Factors for Successful Laser Welding
1. Laser Type: Fiber (metals), CO₂ (non-metals), pulsed/continuous.
2. Shielding Gas: Argon, nitrogen to prevent oxidation.
3. Surface Prep: Cleanliness, oxide removal.
4. Parameters: Power, speed, focal length.
Applications
Precision: Electronics, medical devices.
Automotive: Battery packs, body welding.
Aerospace: Engine components, titanium structures.
---------Victor Feng