What are the best printing parameters for alumina paste on DLP printers?

Printing parameters can vary depending on the printer and resin system. Generally, a layer thickness of 25–50 microns works well for high-resolution parts. Exposure time is usually between 2 and 5 seconds per layer, depending on the opacity of the paste. The build plate should move slowly, typically 1–3 mm per second, to prevent delamination. Maintaining a vat temperature of around 25–30°C helps ensure consistent flow and curing, and gentle recoating after each layer helps avoid air bubbles or uneven surfaces.

How do I prepare a high solid loading alumina slurry for DLP?

To prepare a high solid loading slurry, start with high-purity alumina powder, typically over 99% purity with particle sizes between 200 nanometers and 1 micron. Disperse the powder uniformly in a photocurable resin using ball milling or planetary mixing. Adding dispersants helps prevent agglomeration and ensures smooth flow. A solid loading of 50–60% by volume is common, balancing viscosity with printability. Finally, remove air bubbles by applying vacuum or centrifugation before printing.

What is the recommended debinding and sintering schedule for alumina printed parts?

A typical schedule involves slowly heating the printed parts to 500°C over 6–12 hours to safely remove organic binders. Sintering is then performed by gradually heating to 1600–1700°C and holding for 2–4 hours, depending on the part size and desired density. Controlled cooling at 1–5°C per minute is recommended to prevent thermal shock and warping. Specific parameters may vary depending on the paste composition, part geometry, and furnace type, so always follow manufacturer recommendations.

What post-processing methods can improve alumina density and translucency?

Density and translucency can be improved using hot isostatic pressing, which reduces porosity and increases density. Polishing can produce optical-quality surfaces and enhance translucency. Applying thin surface coatings can improve smoothness and light transmission. Sintering in a controlled atmosphere helps minimize contamination and prevents unwanted color changes.

Who supplies high-purity alumina paste and powder?

Reputable suppliers of high-purity alumina paste and powder include Tosoh Corporation, which provides high-purity alumina powders for ceramics; Sumitomo Chemical, which offers alumina pastes for additive manufacturing; 3D Ceram and Lithoz, which produce DLP-ready ceramic pastes for industrial printing; and Alfa Aesar (Thermo Fisher), which supplies specialty alumina powders suitable for lab-scale formulations. When selecting a supplier, it is important to check particle size distribution, purity, and rheological properties to ensure compatibility with DLP printing.

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Materials, Ceramic 3D Printing Materials, Composite Tooling, Engineering, Jigs&Fixtures, Manufacturing, Paste, SLA Ceramic, Slurry · CERAMIC SLA

Alumina 3D Printing Paste

OXIDE CERAMICS Al2O3, basic material being useful in many applications for technical ceramics, good mechanical behavior in the high temperatures, the good thermal conductivity, the big electric resistivity, the great hardness, the good wear resistance, the chemical slowness.

Price held 7 days after order.

NDA standard Ships in 1–2 business days

60+AM teams supplied

Lot-to-lotstable rheology & solids

Debind/sinterguidance included

Fast dispatchL.A. stock · M–F

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What your process engineer actually checks

Consistent rheology, repeatable sinter

Every lot ships with solids loading, rheology, and a debind/sinter schedule so green parts sinter to predictable density and shrinkage. Dial the cycle in once, reorder the same paste.

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Questions on solids loading, viscosity, debind ramps, sinter shrinkage, or cracking? A materials engineer answers directly — not a contact-form bot. Most replies in under 4 hours, NDA standard.

About this product

Properties

• Good mechanical strength
• Good thermal conductivity
• High electrical resistivity
• High hardness
• Good wear resistant
• Chemically inert

Applications

• Electric Insulators
• Laboratory devices
• Telecommunication equipment
• Electronical Devices
• Spatial
• Foundry Cores
• Optical Instruments

PHYSICAL AND MECHANICAL PROPERTIES

Density		>3.9 g/cm3
Grain size after sintering		2.2 μm
4-pt bending strength		397 MPa
Weibull modulus		14.сен
Theorical Young modulus		300 GPa
Vickers hardness		16.4 GPa
Fracture toughness		4 MPa.m^1/2
Thermal properties from -50°C to 60 °C
Thermal conductivity at RT		23.3 W/m.K
Thermal expansion coefficient	at -50 °C	3.74 *10^-6 K^-1
	at 20 °C	4.98 *10^-6 K^-1
	at 60°C	5.51 *10^-6 K^-1