Key Requirements for Manufacturing Alumina Ceramics

1. Raw Material Purity Control: The purity of alumina (Al₂O₃) powder is critical, typically requiring ≥95% for general applications and up to 99.9% for high-precision scenarios like electronic components. Impurities such as SiO₂, Fe₂O₃, and Na₂O must be strictly controlled to avoid reducing mechanical strength and thermal stability.

2. Powder Processing Precision: The powder needs to be homogenized, granulated, and milled to a specific particle size (usually 1–5 μm) to ensure uniform packing density during forming. Additives like binders (e.g., polyvinyl alcohol) and plasticizers are added in precise proportions to improve moldability.

3. Forming Process Suitability: Select appropriate forming methods based on product shape and size, such as dry pressing (for simple shapes like discs), isostatic pressing (for complex geometries with uniform density), or extrusion (for tubular products like fuse tubes). Strict control of pressure (100–300 MPa) and temperature during forming is essential to prevent defects like cracks.

4. Sintering Parameter Optimization: Sintering is a key step to achieve densification. The process typically involves heating to 1500–1700°C in air or inert atmosphere, with precise control of heating/cooling rates (5–10°C/min) to avoid thermal stress. For high-purity alumina, sintering aids like MgO may be added to lower sintering temperature and improve densification.

5. Post-Processing Precision: Machining processes such as grinding, lapping, and polishing are required for products needing high dimensional accuracy (tolerance ±0.01 mm) and surface finish (Ra ≤0.1 μm). Post-sintering inspection (e.g., X-ray diffraction for phase analysis, ultrasonic testing for internal defects) ensures product quality meets standards.

I can help you compile a detailed technical specification document for 99% purity alumina ceramic fuse tubes, including specific parameter ranges for each manufacturing step.