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What is Aluminum Titanate, and Why Does It Require Dedicated Alumina Powder?
Aluminum titanate (Al₂TiO₅，Aluminum Titanate) is an advanced ceramic material with an ultra-low coefficient of thermal expansion ( 0.5～1.5×10⁻⁶/℃) and exceptional thermal shock resistance. It can withstand extreme temperature fluctuations above 1000℃ without cracking or deforming, making it widely used in key industrial applications such as non-ferrous metal smelting pipes, automotive engine exhaust systems, high-temperature kiln furniture, and glass furnace forehearths.
Industrial synthesis of aluminum titanate relies on a solid-state reaction sintering method: alumina powder (Al₂O₃) and titanium dioxide powder (TiO₂) are uniformly mixed at a 1:1 molar ratio, molded, and then reacted at 1300～1500℃ to form an aluminum titanate solid solution.
In this process, alumina powder serves as the primary structural raw material; its purity, particle size, and impurity content fundamentally determine the final product's density, thermal expansion stability, and service life. Ordinary industrial alumina—due to high sodium content (typically Na₂O at 0.1%～0.3%) and uneven particle size distribution—tends to form a glassy phase during sintering and suppress normal grain growth. This ultimately increases the thermal expansion coefficient and significantly reduces the thermal shock resistance of the resulting aluminum titanate.
Conclusion: The production of aluminum titanate strictly requires low-sodium, high-purity calcined alumina micro-powder with a narrow particle size distribution.
Key Technical Indicators of Alumina Powder for Aluminum Titanate
Below are the core selection parameters of alumina powder for aluminum titanate, along with a comparison with measured test data for Greatsun Aopeng Group's AL-3GA product:
Greatsun Aopeng Group AL-3GA: Tailor-Made Alumina Solutions for Aluminum Titanate
Ultra-Low Sodium Content: Safeguarding the Core Low-Expansion Performance of Aluminum Titanate
Sodium (Na₂O) is the most harmful impurity in aluminum titanate production. During high-temperature sintering, Na₂O reacts with Al₂O₃ TiO₂ to form a low-melting-point liquid glass phase. This glass phase coats the surfaces of aluminum titanate grains, hindering normal grain growth while significantly elevating the material's thermal expansion coefficient. Industry experience
demonstrates that for every 0.01% increase in Na₂O, the thermal expansion coefficient of aluminum titanate can rise by 5%～8%, and its thermal shock
resistance temperature drop tolerance decreases by 30～50℃.
The measured Na₂O content of Greatsun Aopeng Group's AL-3GA is only 0.0299%, far surpassing the common industry standard of ≤0.05% and ensuring stable, controllable low-expansion characteristics for aluminum titanate right from the raw material source.
Precise Particle Size Control: Optimizing Sintering Activity for Aluminum Titanate
The D50 particle size of alumina powder is not simply "the finer, the better." An overly fine D50 (<1 μm) leads to an excessively large specific surface area and overly high sintering activity, resulting in abnormal aluminum titanate grain growth and degraded mechanical properties. Conversely, an overly coarse D50(>5 μm) leads to insufficient sintering activity and incomplete reaction, leaving residual unreacted alumina that impairs thermal expansion stability.
Greatsun Aopeng Group's AL-3GA features D50 = 2.391 μm，D10 = 0.992 μm，D90 = 5.182 μm，. This narrow and concentrated particle size distribution falls precisely within the optimal sintering activity window for aluminum titanate solid-state reactions—ensuring complete reaction between Al₂O₃ and TiO₂ to form single-phase aluminum titanate without causing uncontrolled grain growth from excessive fineness.
High Purity & Low Impurities: Minimizing Grain Boundary Secondary Phases
AL-3GA achieves an Al₂O₃ purity as high as 99.815%, with Fe₂O₃ at only 0.0019%, SiO₂ at 0.0187%, K₂O at 0.0020%, and CaO at 0.0227%. This extremely low impurity content maximally suppresses the formation of secondary phases and glass phases at grain boundaries during aluminum titanate sintering, resulting in high sintered density, a uniform microstructure, and stable performance.
Greatsun Aopeng Group's Customization Capabilities & Quality Assurance
Customizable Particle Size & Purity Solutions
Different aluminum titanate formulations and sintering processes place varying requirements on alumina powder. Greatsun Aopeng Group can provide customized products with a D50 particle size ranging from 1.5～5 μm tailored to customers' specific formulas, molding methods, and sintering curves. Furthermore, targeted adjustments can be made to key impurity metrics such as Na₂O and Fe₂O₃ to achieve one-on-one raw material matching.
Strict End-to-End Quality Control
From raw material intake to final product delivery, Greatsun Aopeng Group has established a multi-stage quality testing mechanism:
Batch Chemical Composition Analysis: Testing for Al₂O₃,Na₂O,Fe₂O₃,SiO₂,K₂O,CaO
Batch Particle Size Distribution Testing: Measuring (D10 / D50 / D90)Batch BET Specific Surface Area Testing: Monitoring surface area metrics.
Pre-Shipment Re-Inspection: Ensuring accurate, reliable Certificate of Analysis (COA) data prior to dispatch.
Proven Market Validation across Multiple Customers
Greatsun Aopeng Group's customized alumina powder for aluminum titanate has earned long-term, stable adoption by numerous aluminum titanate manufacturers, serving downstream sectors including non-ferrous metal smelting components, automotive exhaust systems, and high-temperature kiln structures. Customer feedback consistently confirms stable finished product qualification rates, broad sintering process windows, and minimal batch-to-batch fluctuation.
Selection & Decision Checklist
Evaluate alumina powder for aluminum titanate according to the following priority rankings:
Na₂O ≤ 0.05%: Non-negotiable requirement; directly dictates core aluminum titanate performance.
Al₂O₃ ≥ 99.5%: Ensures exact stoichiometric ratio and final product purity.
D50 = 1.5～3.0 μm and D90 ≤ 6 μm: Narrow size distribution guarantees uniform sintering.
Batch-to-Batch Consistency: Requires minimal fluctuation across consecutive COA data logs.
Supplier Customization Capability: Ability to fine-tune particle size and purity according to specific formulations.
Greatsun Aopeng Group's AL-3GA low-sodium calcined alumina micro-powder meets all five criteria above, representing a highly reliable raw material choice for aluminum titanate production.
Shandong Greatsun Aopeng Group Environmental New Materials Co., Ltd. — Specialized in customized alumina micro-powder, empowering aluminum titanate industry upgrading with consistent quality.
