Laser Welding and Electron Beam Welding: "High-Tech" for High-End Manufacturing

In high-end fields such as aerospace and microelectronics, traditional fusion welding is difficult to meet the requirements of precision and deep penetration. Laser welding and electron beam welding stand out with their advantages of "high energy density, high precision, and low deformation."

Laser Welding: It uses a high-power laser beam (wavelength 1064nm or 10.6μm) focused on the workpiece surface. The instantaneous temperature can reach over 10,000°C, realizing rapid melting and joining of metals. It features narrow welds and small heat-affected zones, making it suitable for welding thin-walled components and micro-parts, such as smartphone camera brackets and aero-engine blades.

Electron Beam Welding: In a vacuum environment, the electron beam is accelerated and focused to bombard the workpiece. With an energy density as high as 10^6-10^8 W/cm², it can achieve deep penetration welding with an aspect ratio of up to 10:1. It is suitable for thick-walled precision components such as nuclear reactor parts and large gears. However, it has high equipment costs and requires a vacuum environment, resulting in relatively limited application scenarios.

Equipment Composition & Laser Types

A standard laser welding system includes three core components:

Laser Generator: Converts electrical energy into a coherent laser beam.

Optical Transmission System: Guides and focuses the beam (e.g., fiber optics, reflective mirrors).

Workstation: Integrates fixtures, motion controls (robots/linear stages), and protective gas delivery.

Critical Process Parameters & Operational Guidelines

Parameter control directly determines weld quality—even minor deviations can cause defects like porosity or cracks :

(1) Pre-Welding Preparation

Material Cleaning: Remove oil, oxide scales, or coatings using ethanol or sandblasting. For high-reflectivity materials (Al, Cu), pre-treat surfaces to reduce laser reflection.

Focal Positioning: Use negative defocus (focus below the workpiece surface) for deep penetration; positive defocus (focus above) for thin sheets to avoid burn-through.

Industry Applications & Case Studies

Laser welding’s versatility drives innovation across sectors:

(1) Construction & Heavy Industry

Steel Structures: Double-head laser-arc hybrid welding systems weld 20mm+ T-beams at 1.2m/min, reducing deformation by 50%.

Shipbuilding: Robot-guided systems with 7th-axis rails weld 115mm-thick hull plates in single passes, solving the "single-side welding, double-side forming" challenge.

(2) Automotive Manufacturing

Precision welding of transmission components using "keyhole stability control technology" to achieve defect-free circular welds.

Laser tailor-welding of car body panels reduces part count by 30% and weight by 15%.

(3) Advanced Energy & Aerospace

Nuclear Energy: Fiber laser welding of Ni-28W-6Cr alloy (for 850°C molten salt reactors) with crack suppression via parameter optimization.

Aerospace: Welding of titanium alloy engine blades with minimal heat-affected zone (HAZ) to preserve material strength.