A hard anodizing machine is a specialized type of anodizing equipment designed to produce ultra-thick, high-hardness oxide films on aluminum and aluminum alloy surfaces through an enhanced electrolytic process. The core principle involves using the workpiece as the anode under low-temperature, high-current-density conditions in specialized electrolytes (e.g., sulfuric acid, oxalic acid), promoting the formation of a dense oxide layer 20–150 μm thick. It is widely applied in machinery, aerospace, automotive, and mold industries, suitable for components such as cylinders, pistons, cutting tools, and aerospace parts that require extreme wear and corrosion resistance.
Core Components of a Hard Anodizing Machine：
Electrolytic System – The core unit, comprising:
Low-temperature, corrosion-resistant plating tanks (PP or PVDF), capable of withstanding -5 to 10°C,High-stability electrode assemblies, with the workpiece as the anode and lead alloy or graphite as the cathode to reduce electrode wear, and High-power adjustable DC power supply (15–30 V, current density 2–5 A/dm²) to meet the requirements for thick oxide layers.
Low-Temperature Control System – Precisely maintains the electrolyte temperature at -5 to 10°C using refrigeration units, preventing oxide layer dissolution and ensuring desired thickness and hardness.
Electrolyte Circulation and Filtration System – Continuously filters impurities and maintains uniform electrolyte composition, ensuring the dense, high-quality structure of the oxide layer.
Post-treatment Module – Provides sealing (using hot water or salt solutions to enhance corrosion resistance) and optional polishing to optimize surface roughness, further improving component performance.
Key Advantages
Extremely high hardness (HV800–1200), with wear resistance far exceeding standard anodizing, comparable to some metals.
The oxide layer bonds tightly with the substrate, offering strong impact resistance and excellent adhesion.
Superior corrosion resistance, capable of withstanding acidic, alkaline, and salt-spray environments.
Adjustable thickness (20–150 μm) to meet different operational requirements.
The hard anodizing machine is thus a critical solution for surface strengthening and protection of high-end machinery and precision components.
