Alumina Crucibles and Boats

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GENERAL OVERVIEW

Alumina Crucibles and Boats are used by laboratories and manufactures to hold samples and small components during heat treatment.

Chemically inert, alumina doesn’t react with most other materials, ensuring that your samples and components will remain free from contamination. A hard material which is resistant to thermal shocks, acid erosion and other stresses, it can withstand applications involving high pressures and volatile substances. Alumina crucibles are typically reused many times, offering a long service life which lasts several years.

We offer crucibles from 1cm³ to 20cm³ (with non-standard shapes and sizes available to order), as well as ashing boats. Matching lids are available for some designs.

TECHNICAL INFORMATION

Alumina Discs, Plates and Tiles
General Information
Type	95% Alumina	99% Alumina
Max Usage Temp.	1450 °C / 2650 °F	1600 °C / 2900 °F
Bulk Density	3.7 g/cm³	3.8 g/cm³
Open Porosity	<0.5%	<0.25%
Modulus of Rupture @ Room Temp.	250 MPa	300 MPa
Modulus of Elasticity	350 GPa	400 GPa
Thermal Conductivity	25 W/mK	30 W/mK
Thermal Expansion at 20 – 1000 °C	8 x10^-6/K	8 x10^-6/K
KIC Fracture Toughness	2.5 MPam	3.0 MPam
Volume Resistance	<10¹⁴Ωcm	<10¹⁴Ωcm
Dielectric Constant	9	10
Dielectric Strength	20 kV/mm	30 kV/mm
Typical Chemical Analysis
Al₂O₃	95%	99%
CaO	1.8%	0.2%
SiO₂	2.5%	0.3%
MgO	0.5%	0.2%
Fe₂O₃	0.05%	0.03%
Other Oxides	≤0.05%	≤0.03%

All figures are typical figures determined using laboratory test pieces and might not always be an accurate representation of production item.

Standard Types and Sizes

Type	Size (height x diameter/width)
Cylindrical	11 x 20 mm	12 x 40 mm
	14 x 45 mm	16 x 50 mm
	20 x 20 mm	25 x 60 mm
	35 x 30 mm	35 x 100 mm
	40 x 35 mm	48 x 120 mm
	50 x 50 mm	50 x 100 mm
Rectangular	20 x 20 x 15 mm	50 x 20 x 20 mm
	50 x 50 x 25 mm	60 x 30 x 15 mm
	60 x 40 x 20 mm
Tapered	25 x 16 x 21 mm	30 x 20 x 17 mm
	37 x 22 x 33 mm	45 x 25 x 45 mm
	50 x 30 x 48 mm	61 x 35 x 60 mm