Welding Processes

Welding processes use heat or pressure to join parts together. They are primarily categorized into three types: fusion welding, pressure welding, and brazing. Fusion welding forms the weld by melting the parent material, and arc welding is widely used. Pressure welding, such as resistance spot welding, requires pressure to complete the connection. Brazing uses a low-melting-point filler metal to achieve wetting and diffusion bonding. Modern technologies, including CMT cold metal transfer (CMT) technology, DeltaSpot resistance spot welding, laser hybrid welding, and friction stir welding, can weld ultra-thin sheets as thin as 0.3 mm and optimize heat input control.

This method is used in the construction, shipbuilding, aerospace, and new energy vehicle sectors, such as welding Tesla's all-aluminum bodies and CATL's power battery modules. China accounts for over 50% of the world's annual welding material production. Intelligent welding equipment integrates AI algorithms and vision sensors to enable real-time parameter adjustment. Nuclear power plant overhauls utilize a segmented, multi-layer filling process to ensure weld quality. The welding robot market is projected to reach 107.8 billion yuan in 2027.

Precision Welding

Precision welding refers to welding and joining processes that achieve precise shapes through high energy density. It includes laser welding, electron beam welding, diffusion welding, near-net-shape welding, brazing, bonding, and adhesive bonding, and falls under the discipline of metallurgy. Its process characteristics require that the mechanical properties and surface condition of the base material after welding must not be less than the original design requirements, and that the power-on time be controlled in milliseconds to seconds. It is applicable to fields such as microelectronics, aerospace, automotive, and medical device manufacturing.

Laser welding uses a focused high-energy laser beam to melt the workpiece surface. Electron beam welding requires a vacuum environment and consists of four major systems, including an electron gun. Diffusion welding can join dissimilar materials while maintaining machining accuracy. Near-net-shape welding uses layer-by-layer buildup to create large, complex components, achieving metal utilization rates exceeding 80%. QCW quasi-continuous wave (QCW) laser welding technology combines the characteristics of pulsed and continuous lasers to achieve micron-level precision welding, and is used in applications such as welding tabs for new energy lithium batteries.