Aluminium Titanate (Al₂TiO₅)
Aluminium titanate (ATI, ALUTIT T, Al2TiO5) is a high-performance ceramic material with an extraordinary property: components made from this material withstand even abrupt temperature changes of several hundred degrees without damage – and this despite the material having comparatively low mechanical strength. What appears to be a contradiction at first glance is the result of a unique material structure.
CeramTec helps foundries and metal processing companies significantly extend the service life of their casting equipment – through ceramic components made from ALUTIT T that reliably perform where conventional ceramics and metals fail.
Key Facts at a Glance
- Thermal shock resistant up to 900 °C temperature differential – direct contact with the melt possible – without preheating
- Lowest thermal expansion of any technical ceramic: < 1 × 10⁻⁶ K⁻¹ – for comparison: aluminium oxide is ~8 × 10⁻⁶ K⁻¹
- Ideal for foundries, aluminium die casting, and non-ferrous metal melts – no wetting by metal melts
- CeramTec manufactures riser tubes from ALUTIT T in lengths up to 1.75 m – individually customised at the production site in Germany
Our Products with ALUTIT T
- Riser tubes for ceramic low-pressure permanent mould casting (up to 1.75 m in length): CeramTec manufactures riser tubes from ALUTIT T in standard lengths from 0.5 m up to 1.75 m. Thanks to the material's physical non-wettability by liquid aluminium, no elaborate preheating processes are required – this reduces energy consumption per casting cycle by up to 15%. Optional configurations: with flange, with circumferential groove, with boron nitride coating.
- Dosing tubes for continuous dosing furnaces in aluminium die casting production: The exceptionally low thermal conductivity of ALUTIT T (1.5 W/mK – approximately 10\times lower than steel) reduces the temperature gradient in the melt and delays solidification. The result: greater process reliability, measurably more consistent dosing quantities, and energy savings during ongoing operation.
- Break rings for the continuous casting of brass and copper alloys: In the thermally extreme conditions of continuous casting, ALUTIT T excels with maximum thermal shock resistance (>900 °C air/liquid) and chemical resistance to brass melts – properties that no other ceramic in this application field can combine.
- Further standard products: Bushings as casting mould inserts or connecting elements | Nozzles as casting mould inserts | Insulating rings | Slide plates for flow control | Spouts | Stoppers | Closure plates
Customised Solutions
Don't see what you need? No problem – CeramTec develops and manufactures aluminium titanate special components (Al₂TiO₅) precisely to your technical specifications: from the concept drawing through to series production. Possible special components include, among others:
- Spacers for casting fixtures
- Casting moulds and casting mould inserts made from ceramic
- Mouthpieces for extrusion and die casting systems
- Port liners for combustion engine prototypes
Properties of Al₂TiO₅
| Property | Value | Benefit for the User |
|---|---|---|
| Thermal shock resistance | Up to 900 °C temperature difference | Direct contact with melt possible – even without preheating |
| Thermal expansion | < 1 × 10⁻⁶ K⁻¹ (20–600 °C) | Low mechanical stress during operation, longer service life |
| Thermal conductivity | 1.5 W/mK | Energy savings and delayed solidification of the melt |
| Non-wettability | Towards non-ferrous metal melts | No contamination of the metal melt by ceramic degradation products |
| Chemical resistance | Very good | Higher metal melt purity, less scrap |
| Max. operating temperature | 900 °C | Suitable for all common non-ferrous metal casting processes |
How is ALUTIT T produced?
During manufacturing, high-purity aluminium oxide (Al₂O₃) and titanium oxide (TiO₂) combine in a specially defined reaction process at temperatures above 1,400 °C to form a microporous material. The resulting microstructure is permeated by a fine network of microcracks – and it is precisely this structure that is the key: it selectively dissipates thermal stresses and gives ALUTIT T its outstanding thermal shock resistance.
The very low thermal expansion (< 1 × 10⁻⁶ K⁻¹) and the controlled porosity within the microstructure contribute additionally to thermal stability. Since liquid metals are virtually unable to wet aluminium titanate, the material is furthermore ideally suited for use in foundries and metallurgical melting operations – particularly in aluminium casting.
Tips for Optimal Use
- Caution with mechanical impact: As a ceramic material, ALUTIT T is sensitive to knocks – particularly during installation and cleaning.
- Cleaning: Use only rounded, wooden tools – no metal hammers or chisels.
- Installation: Take into account the differing thermal expansion compared to metallic fixtures; use suitable sealing material.
- Aluminium/slag deposits: Remove immediately after withdrawal from the melt, while the material is still warm.
FAQ - CeramTec Aluminium Titanate (Al₂TiO₅)
Is aluminium titanate better than aluminium oxide for high-temperature applications?
That depends on the application: Aluminium oxide (Al₂O₃) offers higher strength and hardness. Aluminium titanate Al₂TiO₅), on the other hand, is superior when it comes to abrupt temperature changes – its thermal shock resistance of up to 900 °C temperature differential makes it the first choice in foundries.
How does ALUTIT T differ from standard aluminium titanate?
ALUTIT T is CeramTec's proprietary further development of the Al₂TiO₅ material. Through a specially controlled sintering process and an optimised raw material composition, we achieve a defined microcrack structure that delivers consistently reproducible thermal shock values – in contrast to generic aluminium titanate, which can exhibit significant batch-to-batch variation.
What does a riser tube made of aluminium titanate cost?
Costs vary depending on component size and specification. Due to the significantly longer service life compared to alternative materials, the total cost of ownership is generally more favourable. Please contact us for an individual quote.