1185 mirror aluminum sheet
1185 Mirror Aluminum Sheet: A Reflective Alloy Engineered for Signal, Safety & Sensor Performance
1185 mirror aluminum sheet is often treated as “just another reflective aluminum.” In reality, it is a highly specialized aluminum alloy whose chemical simplicity and surface purity make it uniquely suited for optical signaling, light guidance, and sensitive environments where surface contamination, electrical neutrality and chemical stability are critical.
Instead of viewing 1185 purely as a decorative mirror sheet, it’s far more accurate to regard it as a functional, optically active material that happens to look like a mirror.
1. What Makes 1185 Mirror Aluminum Different?
1.1 Alloy Philosophy: Purity as a Functional Design Parameter
Most mirror aluminum sheet products use popular alloys like 1050, 1060, 3003 or 5005. Alloy 1185 is different because:
- It is designed for high aluminum content (typically ≥ 99.5% Al).
- Alloying elements (Fe, Si, Cu, Mn, Mg, etc.) are intentionally kept at very low levels.
- It is optimized not for strength or formability alone, but for:
- Stable, uniform oxidation (for consistent reflectivity).
- Excellent electrical conductivity.
- Low risk of inclusions and surface streaks, which degrade optical quality.
This makes 1185 mirror aluminum sheet an ideal choice where light performance and signal clarity matter more than mechanical strength—such as:
- Road and traffic sign substrates with reflective films
- Safety marking systems and emergency guidance
- Display light boxes and internal reflective cavities
- Infrared and visible-light sensor housings
- LED light reflectors and architectural light-traps
2. Technical Parameters of 1185 Mirror Aluminum Sheet
Typical technical parameters (can vary by manufacturer specification):
2.1 Available Tempers
- O (Annealed) – Maximum ductility, easy deep drawing or highly formed components.
- H14 – Half-hard, balanced strength and formability (common for cladding, light reflectors).
- H16 / H18 – Higher hardness, better flatness for large-area sheets and panels.
- Custom tempers (e.g., H24, H26) possible as per project requirement.
Mirror-finish 1185 is most commonly supplied in H14–H18 tempers for dimensional stability during surface treatment and installation.
2.2 Typical Dimensions
- Thickness range: 0.2–2.5 mm
- 0.20–0.5 mm – Light reflectors, lighting components, optical interiors
- 0.5–1.0 mm – Sign substrates, decorative panels
- 1.0–2.5 mm – Structural signage, interior/exterior panels
- Width: 500–1600 mm (customized up to line capacity)
- Length:
- Coil: continuous, inner diameter usually 305 / 405 / 505 mm
- Sheet: 500–6000 mm, or cut-to-size
2.3 Surface Grades & Types
- Standard mirror: Raw mirror finish from rolling and polishing.
- High-reflective / high-brightness mirror: Optimized rolling and finish, higher total reflectivity.
- Anodized mirror 1185:
- Transparent oxide film for scratch and corrosion resistance.
- Better color stability and durability outdoors.
Gloss and reflectivity can be tuned according to application—for example traffic signs vs. interior luminaires vs. decorative panels.
3. Chemical Composition: Why Purity Matters Optically
A simplified typical chemical composition of 1185 alloy (mass %):
| Element | Typical Range (wt%) |
|---|---|
| Aluminum (Al) | Balance (≈ 99.5 min) |
| Silicon (Si) | ≤ 0.30 |
| Iron (Fe) | ≤ 0.40 |
| Copper (Cu) | ≤ 0.05 |
| Manganese (Mn) | ≤ 0.05 |
| Magnesium (Mg) | ≤ 0.05 |
| Zinc (Zn) | ≤ 0.10 |
| Titanium (Ti) | ≤ 0.03 |
| Others (total) | ≤ 0.10 |
(Note: Specific composition limits may be adjusted to match GB/T, EN or customer specifications.)
3.1 Optical Consequence of Impurities
- Iron and silicon create localized differences in hardness and etching behavior, producing:
- Light-scattering micro-pits
- Rolling lines or gloss variations
- Reduced specular (mirror) reflectivity
- Copper, manganese and magnesium increase strength slightly, but:
- Reduce corrosion resistance in some atmospheres.
- Can influence oxide film uniformity on anodized surfaces.
The primary engineering idea behind 1185 alloy is:
“Minimize elements that destabilize or ‘roughen’ the surface at micro-scale, in order to maintain a smooth, optically uniform mirror plane.”
4. Mechanical & Physical Properties
Even though 1185 is designed for purity and surface qualities, its mechanical profile still matters in converting, forming and service.
4.1 Typical Mechanical Properties (for reference)
Temper O (annealed):
- Tensile strength: 60–95 MPa
- Yield strength: 20–40 MPa
- Elongation (A50): ≥ 25%
Temper H14:
- Tensile strength: 95–130 MPa
- Yield strength: 60–100 MPa
- Elongation (A50): 6–15%
These values may vary by thickness and production route but show that 1185:
- Remains soft to medium-hard.
- Is extremely formable in O temper.
- Has good stiffness-to-weight ratio in H14 / H16 / H18 for large flat reflector panels.
4.2 Physical Properties
- Density: ~2.70 g/cm³
- Melting range: 645–660 °C
- Electrical conductivity: High (comparable to 1xxx series)
- Thermal conductivity: Very good (approx. 220 W/m·K class)
These characteristics mean 1185 mirror aluminum sheet:
- Dissipates heat effectively in lighting housings and LED reflectors.
- Does not generate significant hotspots, helping to maintain optical coatings and adhesives.
5. Standards & Implementation Specifications
1185 mirror aluminum sheet production and performance draw on:
- National/International Alloy Standards
- GB/T series (China national standards)
- EU EN 485 / EN 573 series (aluminum and its alloys)
- Equivalent to 1xxx high-purity, low-alloy standardized grades.
- Enterprise / Factory Standards
For mirror production, the truly critical aspects are usually in:- Enterprise internal standards for:
- Surface roughness (Ra / Rz).
- Specular reflectance (% at specific wavelengths).
- Defect limits (scratches, pits, roller marks, stains).
- Thickness tolerance and flatness grade.
- Enterprise internal standards for:
- Surface & Anodizing Standards
- Oxide layer thickness: commonly 5–15 μm for architectural interior, ≥ 15 μm for exterior use (if anodized).
- Color consistency, sealing quality (e.g., nickel acetate seal).
A credible 1185 mirror aluminum sheet supplier will specify:
- Alloy designation and temper.
- Standards followed (national + internal).
- Typical total and specular reflectivity ranges.
- Flatness tolerance and burr control for high-speed conversion (e.g., traffic sign manufacturing).
6. The “Hidden” Engineering Priorities in Mirror Production
Standard alloy data doesn’t capture what really determines mirror quality. From a process viewpoint, 1185 mirror aluminum sheet is anchored on three invisible parameters:
6.1 Surface Micro-Flatness
Mirror aluminum is essentially an engineered reflection surface created by controlled rolling and polishing:
- Ra values are controlled at sub-micron level.
- Any local distortion—like rolling chatter marks or uneven stress—creates visual waviness, especially on large panels.
- In higher-hardness tempers (H18), better retention of rolled flatness is achievable—important in large signage and lightboxes.
6.2 Oxide Layer Geometry
All aluminum instantly forms an oxide layer. In 1185:
- The nearly pure matrix allows for an even oxide thickness and density.
- When anodized, pore size and distribution are very uniform, which:
- Enhances predictable reflection properties.
- Improves bonding performance with reflective films and coatings.
6.3 Inclusion & Defect Control
Because alloying and impurities are limited:
- There are fewer hard inclusions to scratch polishing rolls or create:
- Black spots.
- Surface cracks.
- Micro-fissures visible in bright light.
- That translates directly into:
- More stable high-gloss finish across wide coils.
- Higher yield during deep drawing and forming.
7. Optical Behavior: More Than Just “Shiny”
7.1 Reflectivity
Typical total reflectance (indicative values, depends on finish and process):
- Standard mirror (as-rolled/polished): 80–86% total reflectivity.
- High-brightness or specially polished: up to ≥ 86–90%.
- Specular reflectance at certain angles can be tailored via polishing sequences.
Where specular reflectance is (e.g., LED reflectors, light channels), 1185’s consistent grain structure and purity help stabilize performance across batches.
7.2 Spectral Performance
Because alloying elements and their oxides can absorb or scatter particular wavelengths, 1185’s low alloy content provides:
- Smooth, broadband reflection in visible wavelengths.
- Predictable performance in near-infrared, useful for:
- IR sensor housings.
- Light-measuring equipment interiors.
This creates more controlled light paths, less color shift, and more accurate optical simulations compared to more heavily alloyed grades.
8. Processing & Forming Behavior
8.1 Forming
In O temper, 1185 mirror aluminum sheet can be:
- Deep drawn.
- Rolled, bent, flanged.
- Stamped into complex shapes: bowls, linear reflectors, housings.
In H14–H18:
- Excellent for bending and roll forming.
- Best used where moderate shaping combined with stable flatness is needed (panels, trays, covers).
To protect the mirror surface, high-end producers supply:
- PE or protective film on one side (or both sides when needed).
- Controlled-edge conditioning to avoid burrs scratching stacked sheets.
8.2 Surface Treatments
1185 mirror aluminum sheet can be:
- Anodized – colorless or tinted, with controlled layer thickness.
- Coated (PVDF / polyester) – though mirror effect decreases with thick coatings, certain clear topcoats are possible.
- Laminated with films for:
- Traffic signs and safety markings.
- Decorative or branding layers.
Purity helps ensure consistent wetting, adhesion and color appearance across entire lots.
9. Corrosion & Environmental Performance
Because 1185 resembles the 1xxx series in purity:
- Intrinsic corrosion resistance is excellent in most indoor and mild outdoor conditions.
- Reduced copper and heavy alloying levels minimize:
- Galvanic spots.
- Pitting tendency in many atmospheres.
- With anodizing:
- Salt spray resistance (for architectural and traffic environments) is greatly improved.
- Surface becomes more scratch and finger-print resistant—ideal for exposed mirror-panel installations.
Considering it as a functional reflective system, 1185 mirror aluminum sheet is particularly valuable when:
Signal Needs to Be Clear and Stable
- Road traffic signs and directional boards.
- Emergency exit guidance systems.
- Reflective posts and tunnel reflectors.
Lighting Efficiency Is Critical
- LED fixture reflectors.
- Interior light channels and auxiliary reflectors.
- Light boxes and display case interiors.
Optical Integrity & Clean Surfaces Matter
- Instrument and sensor housings.
- Medical or laboratory observing reflectors.
- Control panel covers and monitor integration frames.
Weight & Appearance Have to Align
- Architectural ceilings with reflective panels.
- Interior cladding where perceived space and brightness are key.
11. Integrating 1185 Mirror Aluminum Into Your Specification
When writing technical or procurement specifications for 1185 mirror aluminum sheet, you can include:
Alloy & Temper
- Alloy: 1185
- Temper: O / H14 / H16 / H18 (as required)
Chemical Composition (Abbreviated)
- Al ≥ 99.5%,
- Si ≤ 0.30%, Fe ≤ 0.40%, Cu ≤ 0.05%, Mn ≤ 0.05%, Mg ≤ 0.05%, Zn ≤ 0.10%, Ti ≤ 0.03%, others ≤ 0.10% (total)
Mechanical Requirements
- Tensile and yield strength ranges.
- Minimum elongation.
- Thickness-based tolerances according to EN/GB or factory standard.
Surface Specification
- Mirror grade (standard / high-brightness / anodized).
- Required total reflectance (e.g., ≥ 85% at 550 nm).
- Maximum roughness (e.g., Ra ≤ X μm).
- Defect class: no visible scratches, stains, or pits at specified viewing distance.
Conversion & Protection
- PE protective film on mirror side.
- Cut-to-size tolerance, flatness, burr limits.
- Anodizing thickness if required (e.g., ≥ 10 μm for interior, ≥ 15 μm for exterior).
Using 1185 from this more deliberate, performance-focused perspective helps ensure:
- High and repeatable mirror quality.
- Geometrically stable panels and components.
- Long-term durability of optical performance, even in demanding environments.
