What is the technology of molded alumina ceramics

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Aluminum oxide ceramics (Al ₂ O3 ceramics) are widely used in fields such as electronics, machinery, chemical, medical, and aerospace due to their excellent mechanical strength, high hardness, high temperature resistance, corrosion resistance, and good insulation properties. However, traditional ceramic manufacturing processes such as injection molding and isostatic pressing have problems such as low efficiency, high cost, and poor consistency when producing complex shapes or high-precision parts. As an efficient and high-precision molding technology, compression molding can effectively solve these problems and become an important method for industrial production of alumina ceramics.

Overview of Aluminum Oxide Ceramic Technology by Compression Molding
Compression molding is a dry molding process that involves mixing alumina powder with a small amount of binder, pressing it into a predetermined shape under high pressure, and then sintering it at high temperature to obtain dense ceramic products. This technology is suitable for large-scale production of ceramic components with simple or moderately complex shapes, such as electronic substrates, wear-resistant parts, sealing rings, cutting tools, etc.

technological process
The main steps of molding alumina ceramics by compression molding include:

1. Raw material preparation: High purity alumina powder (usually α – Al ₂ O3) is mixed with a small amount of organic binder (such as PVA, PVB) to improve the flowability and formability of the powder.
2. Mold design: Design steel molds according to the shape of the product to ensure high dimensional accuracy of the pressed blank.
3. Compression molding: Under a pressure of 10-200 MPa, the powder is compressed and molded in the mold to form high-density green bodies.
4. Demolding: Remove the green body from the mold to avoid cracking or deformation.
5. Sintering: Sintering at high temperatures of 1500-1700 ℃ to densify the green body and form high-strength ceramics.

Advantages and Solutions of Compression Molding Technology
Compared with other ceramic molding methods such as injection molding, extrusion molding, isostatic pressing molding, etc., compression molding technology has the following significant advantages:
High production efficiency, suitable for large-scale manufacturing
-Problem: Traditional grouting molding relies on gypsum molds to absorb water and solidify, with a long production cycle (several hours to several days) and low efficiency.
-Solution: The compression molding adopts mechanical pressing, and the single piece molding time only takes a few seconds to a few minutes, which is suitable for automated continuous production and greatly improves production capacity.

High dimensional accuracy, reducing subsequent processing
-Problem: Products formed by grouting and isostatic pressing have a large shrinkage rate and significant size fluctuations, requiring additional precision machining.
-Solution: The density of the molded body is uniform, the sintering shrinkage is controllable (usually 5-15%), and the product size tolerance can be controlled within ± 0.1%, reducing subsequent grinding costs.

High material utilization and reduced waste
-Problem: Traditional molding methods such as injection molding and casting may generate a large amount of waste or solvent pollution.
-Solution: Compression molding is a dry process with no liquid medium, recyclable waste, and a material utilization rate of over 95%.

Suitable for complex shapes and high-strength requirements
-Problem: Ordinary pressing techniques are difficult to form complex structures (such as thin-walled and irregular holes).
-Solution: By optimizing mold design and powder flowability, compression molding can produce ceramic parts with complex shapes such as steps and grooves, while maintaining high strength (bending strength can reach 300-400 MPa).

Significant cost-effectiveness
-Problem: The isostatic pressing equipment is expensive, and the labor cost for injection molding is high.
-Solution: The investment in molding equipment is relatively low, suitable for small and medium-sized ceramic enterprises, with high automation, minimal manual intervention, and lower overall costs.

Application of molded alumina ceramics
Due to the high efficiency and precision of compression molding technology, the produced alumina ceramics are widely used in:
-Electronics industry: integrated circuit substrates, insulating ceramic chips, sensor housings.
-Mechanical industry: wear-resistant ceramic liners, bearings, cutting tools.
-Chemical industry: corrosion-resistant valves, pump components.
-Medical industry: dental implants, artificial joints.
-Energy industry: fuel cell membranes, high-temperature stoves.

The technology of molded alumina ceramics has become one of the preferred methods for industrial production of high-performance ceramics due to its advantages of high efficiency, high precision, and low cost. It solves many pain points of traditional molding processes, such as long production cycles, low dimensional accuracy, and large material waste, and has shown broad application prospects in fields such as electronics, machinery, and healthcare.

Brudeze Ceramics supplies and sells a wide range of high-quality quartz glass, including alumina ceramics, zirconia ceramics, silicon nitride ceramics, aluminum nitride ceramics, silicon carbide ceramics, boron carbide ceramics, bioceramics, machinable ceramics, etc. We can meet the customization requirements of various ceramic products.