Metals: Surface Treatments for Metals
Design & Technology: AQA GCSE, topic 4.10.2
Surface Treatments for Metals
There are a number of commonly used surface treatments for metals.
Metallic finishes
- Metal surfaces can be finished to achieve desired appearances.
- For example, polished, brushed, or satin finishes.
- Metallic finishes are achieved through mechanical processes.
- For example, grinding, sanding, or buffing.
- These mechanical processes alter the surface texture and appearance.
Conversion coatings
- Conversion coatings are applied to metals to improve their resistance to corrosion.
- Conversion coatings provide a base for subsequent treatments or coatings.
- Conversion coatings include:
- Chromate conversion coatings.
- Phosphate coatings.
- Black oxide coatings.
Case hardening
- Case hardening is a heat treatment process.
- During case hardening, the metal surface is heated and then cooled rapidly.
- This process creates a hardened outer layer.
- The hardened outer layer improves wear resistance.
Nitriding
- Nitriding is a heat treatment process.
- During nitriding, nitrogen is diffused into a metal surface at elevated temperatures.
- This process creates a hard and wear-resistant layer.
Etching
- Etching is a controlled chemical or electrochemical process.
- Etching involves removing material to create visual and textural effects.
- Etching is used to create:
- Patterns.
- Logos.
- Designs.
Test yourself on Metals: Surface Treatments for Metals
What surface treatment creates visual and textural effects?