Views: 0 Author: Site Editor Publish Time: 2026-05-06 Origin: Site
Design and mold making
Aluminum alloy sheet pretreatment
CNC cutting
Tire frame assembly and positioning welding
Fully welded
Post weld treatment and correction
Surface treatment
Powder coating of aluminum alloy bottom shell
3D modeling and simulation: Based on ship design, use CAD/CAE software for 3D modeling of the bottom shell. Structural strength, fluid dynamics, and molding process simulations are required to optimize the layout, height, and shape of ribs (reinforcing ribs).
Plate selection: Usually 5000 series (such as 5083, 5086) or 6000 series (such as 6061-T6) marine grade aluminum alloy is selected. These alloys have excellent corrosion resistance (especially against seawater corrosion), weldability, and moderate strength.
Ship shell plate: CNC plasma cutting or waterjet cutting is used to cut side plates, bottom plates, bow sealing plates, etc. with a certain three-dimensional curvature from aluminum plates.
Structural components: keels, ribs, longitudinal trusses, etc. are usually cut from aluminum alloy extruded profiles or thick plates. The use of profiles can improve structural efficiency and simplify processes.
Construction of tire frame: Create a rigid steel tire frame that perfectly matches the bottom line of the ship as a reference platform for construction.
Skeleton assembly: Position and install internal skeletons such as keels, ribs, and longitudinal trusses on the tire frame in sequence, and fix them with temporary brackets to form a "skeleton cage".
Skin and positioning welding: Lift and cover the pre bent ship shell onto the skeleton, and use fixtures (such as "horse boards") to tightly adhere and temporarily fix it. Then, the welder performs intermittent positioning welding to preliminarily connect the hull plate with the internal skeleton, forming a complete hull shape.
Welding method: MIG (Metal Inert Gas Welding) is mainly used, and TIG (Tungsten Inert Gas Welding) may be used for some key parts or thin plates. Use high-purity argon gas as a protective gas.
Welding sequence: Strictly follow the process specifications, usually following the principle of "welding from the middle to both sides, from bottom to top, and symmetrically" to control welding deformation and stress.
First, weld the connection joints between the internal skeletons.
Re weld the fillet weld between the hull plate and the internal skeleton (this is the main strength weld).
Finally, weld the butt joint between the ship's shell plates (requiring a groove to ensure full penetration).
Welder requirements: It must be operated by professional aluminum welders holding a classification society certificate. Aluminum alloy welding requires extremely high cleanliness (no oil stains, oxide layer) and environmental (windproof, moisture-proof) requirements.
Post weld treatment and correction
Weld cleaning: Use stainless steel wire brushes or specialized tools to clean all welds, removing oxide layers and welding slag.
Deformation correction: Due to the thermal deformation caused by welding, flame correction (using a welding gun to locally heat a specific area and then cool and shrink to correct) or mechanical correction methods should be used to restore the hull line shape to within the tolerance range.
Anodizing: This is the most commonly used and critical treatment process. Generate a hard, wear-resistant, and corrosion-resistant oxide film on the surface of aluminum through electrochemical methods (such as hard anodizing). This layer of film is usually dyed gold, black, or maintains its original color, greatly enhancing its aesthetics and durability.
Spray painting/spray coating: Some products may undergo additional polyurethane or powder coating after anodizing, providing more color options and additional protection, but high-end products usually focus on anodizing.
Pre treatment: degreasing, cleaning, and forming a dense conversion film on the aluminum surface through chromization or zirconation, which is the key to adhesion.
Covering: Protecting areas that do not require spraying, such as adhesive surfaces.
Electrostatic spraying: In a dedicated spraying room, the negatively charged powder coating is uniformly adsorbed onto the grounded workpiece.
High temperature curing: Melt and crosslink in a drying oven at 180-200 ℃ to form a hard coating.
Inspection: Check the appearance, thickness, and adhesion.
Aluminum alloy bottom shell has obvious advantages in rigidity, durability, deformation resistance (not easy to warp), environmental protection (fully recyclable), and easy maintenance (can be washed with clean water), making it the mainstream choice for high-performance inflatable boats such as RIB hard bottom inflatable boats.
The production of aluminum alloy inflatable hull is a capital and technology intensive precision manufacturing process, which relies on high-quality aluminum alloy materials, high-precision large molds, and strict CNC machining and surface treatment processes.
