Anodizing of aluminium and its alloys - Instrumental determination of image clarity of anodic oxidation coatings - Instrumental method
1Key Takeaways
This document specifies an instrumental method for determining the image clarity of anodic oxidation coatings on aluminium and its alloys by measuring reflection from the surface with the help of a sliding combed shutter. The test can only be applied to a flat surface which can reflect the image onto the limited combed…
2Expert Interpretation
This in-depth analysis of ISO 10216:2017, covering the instrumental method for determining the image clarity of anodic oxide coatings on aluminum and aluminum alloys, covers measurement principles, instrument configuration, sample processing, data calculation, and the grading system. It also provides professional implementation advice and analysis of the standard's evolution.
Analysis of the Standard's Core Content
ISO 10216:2017 specifies an instrumental method for measuring the image sharpness of anodic oxide coatings on aluminum and aluminum alloys using an optical comb shutter. This method quantitatively characterizes the image sharpness of coatings by measuring the intensity of reflected light from the surface and is suitable for testing flat samples.
Key Technical Parameters
| Components | Technical Requirements | Allowance Deviation |
|---|---|---|
| Slit | Width 0.02mm | ±0.01mm |
| Combine Shutter | 5 Specifications (0.125-2.0mm) | Transmittance/Shading Ratio 1:1 |
| Test Angle | 45°Incident/Reflection | ±0.5° |
Measurement principle and calculation
Image clarity is calculated based on the formula Cn=(Mm)/(M+m)×100%, where:
- M: Maximum light intensity value
- m: Minimum light intensity value
- n: Comb shutter width
The standard has newly added calculation formulas for optical uniformity (E) and light dispersion (D) to comprehensively evaluate coating quality.
Standard Evolution and Major Changes
Compared to the 2010 edition, the third edition has the following major revisions:
- Revised slit width tolerance requirements
- Optimized illustrations
- Added a comb-shaped sliding shutter diagram
- Improved specimen handling requirements
These changes result in more accurate measurement results, especially for high-gloss surfaces.
Implementation Recommendations
Specimen Handling
Use a solvent such as ethanol to clean the surface, avoiding solvents that form a protective film. The recommended standard size is 50×50mm, avoiding edge deformation areas.
Measurement Optimization
- A 0.125mm comb shutter is recommended for mirror samples
- A 0.5mm specification is recommended for routine testing
- Anisotropic materials require bidirectional measurement in both the vertical and horizontal directions
Data Report
Must include: clarity value table, grading results (S/A/B/C), optical uniformity E0.5, and light dispersion parameters.