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Yuhua Fused Cast
Advantages and Disadvantages of Cast AZS Zirconia‑Alumina Bricks
Time：
Jul 31,2026
The core advantages of fused AZS bricks lie in their outstanding resistance to glass‑melt erosion and high mechanical strength; their main drawbacks include poor thermal shock resistance, the risk of bubble formation, and a higher cost compared with conventional refractory bricks.
Core Advantages
Outstanding erosion resistance: Its dense corundum–zirconia eutectic structure confers exceptional resistance to high‑temperature glass melts, with a very low erosion rate, making it particularly suitable for highly erosive areas such as the melt pool walls and overflow ports.
High mechanical strength and density: The electrofused casting process yields an extremely low porosity (typically ≤1.5%) and a high bulk density (3.45–4.0 g/cm³), resulting in excellent load-bearing and wear‑resistant properties.
Low-pollution potential (specific grade): By optimizing the manufacturing process—such as adding Nb₂O₅ and employing oxidative electro‑melting—it is possible to produce grades with an exceptionally low bubble‑release rate, meeting the stringent purity requirements of photovoltaic and electronic glass applications.
High-Temperature Structural Stability: It exhibits a high load‑softening temperature and low creep at elevated temperatures, enabling long-term maintenance of the kiln’s dimensional stability.
Main disadvantages
Poor thermal shock resistance: Due to its dense microstructure and lack of crack‑toughening mechanisms, it is prone to cracking and even spalling under rapid heating and cooling, resulting in thermal shock resistance that is significantly lower than that of sintered AZS bricks.
Bubble‑formation risk: In conventional processes, the glass phase tends to decompose and release bubbles at high temperatures; inadequate control can result in “stone” inclusions or bubble defects in glass products (although newer processes have mitigated this issue, it remains a critical control point).
High cost: The raw materials (zircon sand and high-purity alumina) are expensive, and the electric melting process requires temperatures above 1800°C, resulting in substantial energy consumption; consequently, the price is significantly higher than that of sintered bricks and conventional refractory materials.
Processing and masonry pose demanding requirements: the material is hard and brittle, making cutting and machining difficult; during masonry, brick joints must be tightly controlled, and the cooling regime is highly sensitive—improper cooling can easily lead to cracking.
Key Selection Tips
Model compatibility: AZS-33# is suitable for general corrosion‑prone areas; AZS-36# is intended for high‑temperature, highly corrosive zones; AZS-41# is designed for extreme corrosion environments (such as feed inlets and bubbling zones). Higher zirconium content enhances corrosion resistance but also increases cost.
Process distinction: Standard cast bricks have lower density and may exhibit shrinkage cavities, whereas vacuum‑cast bricks offer higher density and fewer defects; selection should be based on the specific requirements of critical kiln components.
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