Background

Typical features of ZIRCAR Zirconia’s Type Buster alumina boards, discs and cylinders include:

· 1600°C, 1700°C & 1800°C Rated Versions

· Alumina or Mullite Bonded

· High Strength

· Low Thermal Conductivity

· 100% Fibers & Binder - No Fillers

· Excellent Machinability

· Non-RCF Composition

Alumina Ceramic fiber boards, discs and cykinders from Zircar Zirconia
Product Overview

Zircar alumina insulation Type Buster is a rigid, fibrous ceramic material produced by vacuum forming alumina fibers with either a high purity alumina binder in Buster A-30 for use at 1600°C or with silica binders in Buster M-35 that form a mullite bond for use at 1700°C. Buster M2-35 is a mullite bonded 1800°C version that exhibits complete dimensional stability to 1700°C.
Properties

Typical properties of Zircar’s Type Buster alumina ceramic fiber boards, discs and cylinders.

Property


Buster M-35


Buster A-30

Density, pounds per cubic foot


35


30

Porosity, %


83


85

Alumina content, %


85


97+%

Thermal conductivity at 1400°C, W/m.K


0.24


0.24

Linear shrinkage, 1hr at 1600°C, %


<3%


3%

Specific heat, J/kg.K


0.25


0.25

Thermal expansion, /°C


5.0x10-6


7.5x10-6

Tensile strength (MOR), psi


350


250

Compressive strength, psi @ 2% compression parallel to thickness


289


45
Boards, Cylinders and Custom Machined Parts

Zircar’s Buster is available in boards, cylinders and custom machined parts. All Buster boards are pre-fired for organic-free use. Their fine grain quality enables precision machining. The even binder distribution allows these materials to be dry machined to tight exacting tolerances with solid carbide or carbide tipped tooling. High tool rotation speeds and slow feed speeds are generally best. Their superior machinability and dimensional stability plus low heat capacity make them ideal for use as setters, supports and process fixtures in both continuous and batch firing furnaces.
Zircar’s Buster M-35 and Buster A-30

High purity silica is the binder in Zircar’s Buster M-35. Silica's strong bond gives Buster M-35 excellent high temperature strength and thermal shock resistance. Buster A-30 has a high purity alumina bond making it well suited for use in high vacuum and reducing atmosphere applications where silica cannot be tolerated, such as in bright annealing furnaces with hydrogen atmospheres.

They both have high electrical resistivity at elevated temperatures allowing them to be used in direct contact with many different resistance heating elements. They show excellent resistance to chemical attack and are not affected by oil or water. They are, however, affected by hydrofluoric acid, phosphorous acid and strong alkalis