Mirror-finished Aluminium Sheet, Anodised Aluminium Sheet, And Mirror-finished Anodised Aluminium Sheet

 Fundamental Definitions of the Three Types: Process Determines Core Characteristics

1. Mirror-Finished Aluminium Sheet

A sheet where the aluminium surface achieves a high reflectivity effect (typically ≥80%) through physical polishing or coating processes. Two common methods are:

Mechanical Polishing: Abrasive materials such as sandpaper or polishing wheels are used to grind the aluminium substrate, directly enhancing surface smoothness;

Coated Mirror Finish: Applying high-gloss lacquer or film coatings (e.g., PET film) to simulate a mirror effect, offering lower costs than mechanical polishing.

Core characteristic: ‘Reflectivity achieved through physical polishing or coating, without electrochemical treatment.’

2. Anodised Aluminium Panels

Panels produced by immersing aluminium sheets in an electrolyte (e.g., sulphuric acid) to generate a dense oxide layer (Al₂O₃, 5-20μm thick) via electrochemical oxidation. This oxide layer may be dyed to present monochromatic finishes (e.g., black, gold) or remain transparent (revealing the aluminium's natural colour). Core characteristics: ‘Achieves corrosion and wear resistance through the oxide layer; surfaces are predominantly matt or semi-matt with low reflectivity (typically ≤30%).’

3. Mirror-Finish Anodised Aluminium Panels

Combining the preceding two processes: aluminium sheets are first mechanically polished to create a mirror-like substrate, followed by anodisation to form an oxide film on the mirror surface. The core characteristic is that it ‘combines the high reflectivity of a mirror finish (reflectance ≥70%) with the corrosion and wear resistance of the oxide film, representing a fusion of “mirror aesthetics and anodic performance”.’

Core Distinctions: Three Key Differences from Process to Performance

Comparison Dimension	Mirror-Finished Aluminium Plate	Anodised Aluminium Plate	Mirror-Finished Anodised Aluminium Plate
Core Process	Physical polishing / Coating application	Electrochemical oxidation (no polishing)	Mechanical polishing + electrochemical oxidation
Surface Reflectivity	High (≥80%, clear reflection)	Low (≤30%, no mirror effect)	Medium-high (≥70%, reflection slightly weaker than pure mirror)
Corrosion & Wear Resistance	Poor (no oxide layer, prone to scratches and corrosion)	Excellent (dense oxide layer, scratch-resistant, sweat-resistant)	Excellent (Oxidation film protects mirror finish, balancing wear and corrosion resistance)
Colour options	Numerous (Coatings available in any colour)	Limited (Oxidation film staining, primarily monochrome)	Limited (Same as anodised plates, mostly monochrome mirror finishes)
Cost	Low	Medium	High

 Application Scenarios: Matching Core Advantages to Requirements

1. Mirror-Finish Aluminium Panels: Emphasising ‘Aesthetics + Low Cost’

Suitable for scenarios with low corrosion/wear resistance requirements but high reflectivity decorative needs:

Interior decoration: Ceiling features, feature walls, display cabinet glass alternatives (e.g., jewellery showcases);

Signage: Lightbox panels, reflective signage surfaces (leveraging high reflectivity for attention-grabbing effects);

Appliance exteriors: Mirrored doors for budget refrigerators/washing machines (typically coated mirrors to reduce costs).

2. Anodised Aluminium Panels: Emphasising ‘Durability + Basic Decoration’

Suitable for scenarios requiring corrosion and wear resistance without reflective demands:

Bathroom hardware: Towel rails, tap bases (resisting bathroom moisture corrosion);

Electronic components: Mobile phone frames, laptop casings (resists daily scratches, conveys understated quality);

Architectural finishes: Interior wall cladding, lift panels (withstands foot traffic abrasion, easy to clean).

3. Mirror-Finish Anodised Aluminium Panels: Emphasising ‘Durability + High Reflectivity’

Suitable for mid-to-high-end applications requiring both mirror aesthetics and corrosion/wear resistance:

Premium appliances: High-end oven doors, smart mirror panels (exudes sophistication while resisting grease and corrosion);

Automotive trim: Interior dashboard mirror panels (withstands prolonged scratching while maintaining reflectivity);

Precision equipment: Medical instrument panels, stage lighting reflectors (corrosion-resistant to disinfectants, requires reflective properties).

Alloy Series Selection: Base Material Determines Fundamental Properties

Different alloys exhibit varying strengths and ductility, necessitating selection based on application scenarios:

Alloy Series	Characteristics	Suitable Panel Types	Typical Applications
Series 1	High purity (≥99.5%)，excellent ductility, low cost	Mirror-finished aluminium sheets (coated type), anodised aluminium sheets	Interior decoration, low-end appliance panels
Series 3	higher strength than Series 1, superior corrosion resistance	Anodised aluminium sheets, mirror-finished anodised aluminium sheets	Bathroom fittings, outdoor light-duty decoration
Series 5	high strength, fatigue resistance	Mirror-finished anodised aluminium sheets (high-end)	Automotive trim, precision equipment panels

 Limitations of Each: Avoiding Misapplication

1. Mirror-Finished Aluminium Panels: Durability is the Achilles' heel

Lacks protective oxide layer, prone to corrosion from sweat and moisture (e.g., blackening in bathrooms);

Coated mirror finishes peel under prolonged friction; mechanically polished surfaces scratch easily (irreparable).

2. Anodised Aluminium Panels: Aesthetic Limitations

Low reflectivity, unsuitable for high-gloss decorative applications;

Limited colour options for oxide layer staining, incapable of complex patterns or gradients (primarily monochromatic).

3. Mirror-Finished Anodised Aluminium Panels: Cost is the Weak Point

Dual-process application increases cost by 30%-50% over pure mirror-finish aluminium sheets and by 20%-30% over standard anodised panels;

Polishing followed by anodisation involves complex processes with low production capacity (delivery lead times extend by 5-7 days compared to the preceding options).

Will mirror-finished aluminium sheets become brighter after anodising?

The effect of anodising on brightness is bidirectional.

Potential reduction in brightness:

Standard anodising generates a porous oxide layer (5–200 micrometres thick) on aluminium surfaces. This microporous structure may increase diffuse light reflection, diminishing the inherent high reflectivity (e.g., 98%) of mirror-finished aluminium to produce a matt or semi-matt appearance.

Potential to enhance or maintain brightness:

Employing ‘bright anodising’ techniques (e.g., specific electrolyte formulations + precise parameter control) can preserve or even intensify metallic lustre post-oxidation. For instance:

- Chemical polishing pretreatment improves substrate surface flatness;

- Gradient voltage electrolysis generates denser, more uniform oxide films;

- Sealing processes reduce micro-pore scattering, yielding near-mirror-like finishes.

Practical Application Cases and Verification

High Reflectivity Products:

Imported anodised mirror-finish aluminium sheets (e.g., German-made) achieve reflectivity exceeding 95%, requiring measurement with an 85°-angle dedicated gloss meter (conventional 60° instruments cannot provide accurate readings).

Performance Comparison:

Unanodised mirror-finish aluminium: Prone to fingerprint marks; reflectivity diminishes with use.

Premium anodised mirror-finish aluminium: Highly stain-resistant; maintains high reflectivity long-term (no discolouration for 10 years indoors).