Pyrophyllite heat treated at 800°C - 1000°C

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Description

Pyrophyllite (Aluminium silicate) is a machinable mineral which, after heat treatment, assumes many of the properties of fired ceramics. It is ideal for prototypes, experimental and pilot scale productions where high accuracy is required on small parts. When this material is heat treated it hardens and its properties change; we therefore supply Pyrophyllite in three grades:

  • The natural material. Extremely easy to fabricate, but of rather low strength.
  • Heat treated to 800 - 1000 °C. This grade is characterized by its low thermal conductivity and coefficient of thermal expansion, resulting in very good thermal shock resistance. This version of the heat-treated material can be machined to final size with tungsten carbide tools.
  • Heat treated to 1250 - 1300 °C. This grade is characterized by its excellent electrical properties, high strength and hardness. This version of the heat-treated material can only be machined with diamond tooling.

Properties

General

Porosity Vvoid

2.64 - 2.68 %

Mechanical

Compressive strength Rmc

103 MPa at 20 °C

Flexural strength σbend

33.7 MPa at 20 °C

Hardness, Mohs HM

5 [-] at 20 °C

Tensile strength Rm

23.4 MPa at 20 °C

Thermal

Coefficient of thermal expansion α

2.9E-6 - 3.5E-6 1/K at 600 °C

Thermal conductivity λ

1.5 W/(m·K) at 20 °C

Vicat softening temperature Tsoft

1600 °C

Technological properties

Chemical composition

Silica - 56.8%, Alumina - 33.37%, Ferric oxide - 0.79%, Titanium Dioxide - 2.42%, Calcium Oxide - 0.29%, Magnesium Oxide - 0.24%

Color

Pink to dark brown

Other

Typical characteristics of the Pyrophyllite material include: Machinable, thermally insulating, good thermal shock properties, good mechanical stability once fired. Typical characteristics of the Pyrophyllite material include: Machinable, thermally insulating, good thermal shock properties, good mechanical stability once fired. The key features of Pyrophyllite Heat Treated at 800 °C - 1000 °C are: Poor heat conductivity (Thermal insulator), good resistance to thermal shock, low coefficient of thermal expansion, good mechanical stability, can still be machined for final sizes with Tungsten carbide tools. When fired to 800 °C - 1000 °C around 1.75 - 2.0 % expansion occurs and must be allowed for when machining, however when fired to these temperatures sizes can be adjusted with carbide tools. Components fired to 1000 °C can be operated continuously at that temperature.

This material data has been provided by Goodfellow.

All metrics apply to room temperature unless otherwise stated. SI units used unless otherwise stated.
Equivalent standards are similar to one or more standards provided by the supplier. Some equivalent standards may be stricter whereas others may be outside the bounds of the original standard.