Aluminum Laser Hermetic Sealing Welding

Difficulties in welding aluminum alloy

Aluminum alloy, as a key material for lightweight manufacturing, presents unique welding challenges due to its high reflectivity (up to 92% for 1070nm laser reflectivity) and rapid oxidation characteristics

  • Oxide Layer Interference

    The melting point of surface aluminum oxide (Al ₂ O3) (2050 ℃) far exceeds that of the substrate (660 ℃), leading to the accumulation of impurities in the melt pool. Actual measurements show that the porosity increases by 300% when the oxide layer thickness is greater than 5 μ m

  • Thermal conduction loss of control

    The thermal conductivity of 209W/m · K causes diffusion in the heat affected zone, and the traditional welding deformation reaches 0.25mm/100mm, which affects the assembly accuracy

  • Environmental sensitivity

    When the oxygen content in the welding area is greater than 500ppm, the porosity is greater than 3.5%, which directly affects the sealing reliability

Related Reading
  • Types of weld cracks
  • Reasons for the formation of pores
  • Determine the depth of weld penetration
  • Reasons for blackening of welds
  • Reasons for weld seam undercutting
  • How to avoid cracks
  • Testing the quality of weld seams
  • Check the sealing effect
Comparison of different processes
Process parameters Traditional TIG Conventional laser welding JM laser
Heat input
Height (200-300J/mm)
Medium (50-80J/mm)
Low (20-30J/mm)
Consistency of melting depth
±15%
±8%
±3%
Oxidation control
Argon protection (O ₂<500ppm)
Local protection (O ₂<100ppm)
Glove box environment (O ₂<1ppm)
Applicable thickness
1-12mm
0.5-6mm
0.5-3mm
Typical porosity
2-5%
0.8-1.5%
<0.3%
Related Equipment
Laser pump source shell
Aluminum alloy hermetic sealing case

  • Material

    Aluminum alloy (shell is 6061, cover plate is 4047)

  • Weld seam inspection

    The weld seam is uniform and flat, without cracks, pores, oxidation blackening, etc

  • Helium Leak Test

    Detection results of helium mass spectrometer leak detector：1*10-11Pa·m³/s

  • Deformation amount

    The deformation before and after welding is less than 0.03mm

Our Quality Management
Standardized process flow
  • Material testing
  • Welding pretreatment
  • Fixture positioning
  • Seal welding
  • Hermetic testing
Triple reliability verification

  • process monitoring

    Real time closed-loop control of welding energy; CCD monitoring system for molten pool morphology

  • Testing methods

    Metallographic analysis (weld penetration and defect detection); Helium mass spectrometry leak detection (sensitivity 5 × 10 ⁻13 Pa · m ³/s)

  • Environment Simulation

    Temperature shock test (-55 ℃) ↔+ 125 ℃ 1000 cycles); 85% RH humidity aging test (2000 hours)

Following standards
  • ASTM B209 Standard for Aluminum and Aluminum Alloy Plates
  • EN 485-2 Aluminum Welding Applicability Certification
  • AMS 2681E Aerospace Laser Welding Process Specification
  • MIL-STD-883 Method 1014 Sealing Test
  • GJB 548B-2005 Reliability of Microelectronic Devices
  • NADCAP Welding AC7114 Aerospace Special Process Certification
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