Hard anodizing is a more complex and advanced surface treatment process than anodizing, which is often applied in the production of aluminum heat sinks. Although hard anodizing and anodizing are similar in name, they have significant differences in process, characteristics and application areas.

Thickness and Hardness Difference

The film thickness of hard anodizing is generally 40-100 microns, while the film thickness of ordinary anodizing is usually 15-25 microns, which gives hard anodizing a significant advantage in wear resistance and corrosion resistance. In terms of hardness, the hardness of hard anodizing generally reaches HV300-500, while ordinary anodizing is HV200-300, hard anodizing has higher hardness.

Difference In Process Conditions

Temperature conditions:The temperature of hard anodizing is generally below 5 degrees Celsius, while the temperature of ordinary anodizing is usually 18-22 degrees Celsius, sometimes up to 30 degrees Celsius.

Voltage and current: Hard anodizing adopts step-by-step increasing voltage, up to more than 100 volts, while ordinary anodizing adopts constant voltage. In addition, hard anodizing has a higher current density, usually 1.5-3A/dm², while ordinary anodizing is 1-1.5A/dm².

               

Lori Hard Anodized Heat Sink

               

Lori Yellow Anodized Heat Sink

Appearance Differences

The oxide film of anodic oxidation is thinner, the color is lighter grey, and it can be tinted with multiple colors after post-treatment process to increase the aesthetics. Hard anode anodizing has a thicker oxide film, darker grey or black in color, and is usually not suitable for decorative purposes, but is more focused on functionality.

Differences in Application Areas

Because hard anodizing has higher abrasion and corrosion resistance, it is particularly suitable for applications that require a high degree of protection, such as aerospace, automotive and precision instrumentation. Ordinary anodic oxidation is widely used in the surface treatment of general metal products, such as aluminum furniture, architectural decorative materials, etc., which is lower cost and can meet the basic protection and decoration needs.

Anodizing and hard anodizing are two very important surface treatment technologies, each with unique advantages and application areas. Anodizing is more decorative and mildly corrosion resistant, while hard anodizing focuses on providing high hardness, high abrasion resistance, and greater corrosion resistance. Whether anodizing or hard anodizing, Lori can take a look at the longevity and functionality of aluminum radiators with different surface treatments based on an assessment of the thermal environment.