ASUS · Advanced Materials · Ceraluminesium Series

Ceraluminesium
Sapphire
FGM — Spec Sheet

A functionally graded MgAl/α-Al₂O₃ chassis material. Corundum-class surface. Intrinsic gemstone coloration. 5-sided ceramic coverage. Lighter than conventional Ceraluminium.

Surface HardnessMohs 9 — Corundum

Core AlloyAZ91-class MgAl (Mg-dominant)

Stack Density (est.)~2.43 g/cm³ — 10% lighter than Ceraluminium

ColorationIntrinsic dopant — never fades or chips

Scratch ResistanceKeys, knives, concrete — no mark

Ceramic Coverage5-sided — full exterior shell

LuminescenceUV · NIR · Afterglow options

ProcessingSpark Plasma Sintering + HIP

Interior FaceL1 MgAl + protective polymer film

Five-Sided Coverage Architecture

Omnidirectional Ceramic Shell

The FGM gradient is pressed radially outward in the sintering mold — not just upward. All five exterior faces receive full L0→L5 coverage simultaneously in a single SPS operation.

The sixth face (interior/bottom) remains at the L1 MgAl alloy layer — not subject to external scratch contact. A TPU or polymer film bonds to this face for corrosion protection and component mounting.

Port cutouts receive individually-pressed ceramic sleeve inserts, maintaining Mohs 9 surface continuity around every opening. Edge radii ≥0.4mm prevent stress concentration at ceramic corners.

The Mg core is fully sealed inside the ceramic shell in normal use. No exposed Mg on any surface the user contacts — critical for corrosion resistance in humid environments.

Result: a chassis that is a sealed gemstone externally, a magnesium skeleton internally.

FGM Layer Stack — Stoichiometry, Thickness & Properties

80–120 µm

Al buffer

900–1100 µm

MgAl Core

150–200 µm

Cermet Lo

150–200 µm

Cermet Hi

100–150 µm

Near-Ceramic

50–100 µm

Corundum

Layer

Stoichiometry

Properties

Thickness

Hardness

L0 — Al Buffer

Chemical isolation

Al (pure)

~99% Al, trace Mg
Prevents Mg+Al₂O₃ reaction
Chemical firewall for Mg core

Density: 2.70 g/cm³
Toughness: ~28 MPa·m½
CTE: 23 µm/m·K

80–120 µm~0.10 mm

2–3Mohs

L1 — Core

MgAl (AZ91-class)

Mg_0.90Al_0.09Zn_0.01

Mg-dominant alloy
Precipitation hardened
Bulk structural layer

Density: 1.81 g/cm³
Toughness: ~25 MPa·m½
CTE: 26 µm/m·K

900–1100 µm~1.00 mm bulk

2–3Mohs

L2 — Cermet Lo

Metal-rich composite

Al_0.70(Al₂O₃)_0.30

70 vol% Al binder
30 vol% α-Al₂O₃
Particle size: 1–5 µm

Density: ~3.1 g/cm³
Toughness: ~14 MPa·m½
CTE: 19 µm/m·K

150–200 µm~0.175 mm

4–5Mohs

L3 — Cermet Hi

Ceramic-rich composite

Al_0.30(Al₂O₃)_0.70

30 vol% Al binder
70 vol% α-Al₂O₃
Particle size: 0.5–2 µm

Density: ~3.5 g/cm³
Toughness: ~6 MPa·m½
CTE: 14 µm/m·K

150–200 µm~0.175 mm

6–7Mohs

L4 — Near-Ceramic

Dense α-Al₂O₃ + trace Al

(Al₂O₃)_0.95·Al_0.05

95 vol% α-Al₂O₃
5 vol% grain-boundary Al
Grain: 200–500 nm

Density: ~3.9 g/cm³
Toughness: ~3.5 MPa·m½
CTE: 8 µm/m·K

100–150 µm~0.125 mm

8–8.5Mohs

L5 — Surface

Doped α-Al₂O₃

α-Al₂O₃ : Mⁿ⁺

>99.5 vol% α-Al₂O₃
0.05–2 mol% dopant Mⁿ⁺
Grain: 100–300 nm

Density: ~3.99 g/cm³
Toughness: ~2.0 MPa·m½
CTE: 7.2 µm/m·K

50–100 µm~0.075 mm

9Mohs

Total nominal wall: ~1.65 mm · Weighted avg density: ~2.43 g/cm³ · vs Ceraluminium Al 6061: ~2.70 g/cm³ · Ceraluminesium Sapphire is ~10% lighter.

L5 Colorway — Dopant Library

Key Dopant Incorporation Reactions

Cr³⁺ isovalent — ruby / emerald-hi

Cr₂O₃+Al₂O₃→2(Al,Cr)₂O₃solid solution

Cr³⁺ = Al³⁺ in charge. Isovalent. No vacancy. Freely miscible. Most processing-friendly dopant in the library.

Ti⁴⁺ + Fe²⁺ charge-paired — sapphire blue

TiO₂+FeO+Al₂O₃→(Al,Ti,Fe)₂O₃

Ti⁴⁺(+4) and Fe²⁺(+2) net to +3 average. Ti→Fe intervalence charge transfer at ~580nm generates blue. Reducing atmosphere maintains Fe²⁺ state.

Ce³⁺ isovalent — UV luminescence

CeO₂ (reduced)→Ce³⁺ in Al³⁺ site5d→4f emission ~420–540nm

Isovalent charge. Large ionic radius (1.01Å vs Al 0.535Å) — keep ≤0.5 mol% to prevent phase separation. Blue-green broadband luminescence under UV.

Nd³⁺ isovalent — NIR / smoky violet

Nd₂O₃+Al₂O₃→(Al,Nd)₂O₃NIR @ ~1064nm

Nd³⁺ isovalent. Visible absorption at 530/580/740/808nm darkens base color to smoky violet. Primary emission NIR 1064nm — the chassis is technically a laser gain medium.

Eu³⁺/Eu²⁺ — red phosphorescence / afterglow

Eu₂O₃→Eu³⁺: ⁵D₀→⁷F₂ red @612nm|Eu²⁺: broad afterglow

Eu³⁺: sharp red emission under UV. Eu²⁺: long-decay blue-green afterglow — glow-in-the-dark behavior. Atmosphere control during SPS selects oxidation state.

Ni²⁺ aliovalent — yellow, vacancy-compensated

NiO+Al₂O₃→(Al,Ni)₂O₃+V″_O

Ni²⁺ replacing Al³⁺ creates charge deficit → oxygen vacancy V″O compensation. Keep ≤0.5 mol%. Co-doping with Ti⁴⁺ eliminates vacancies and restores optical clarity.

Pr³⁺ isovalent — green luminescence

Pr₂O₃+Al₂O₃→(Al,Pr)₂O₃⁴f→⁴f emission ~530nm

Pr³⁺ isovalent. 4f intraconfigurational transitions produce sharp green emission under UV. Daylight: faint yellow-green tint. Under UV: bright green luminescence. Same large-radius caution as Ce, Nd.