1.The General Description
MoSi2 heating elements are resistive heating elements based on molybdenum disilicide. The molybdenum disilicide heating elements prevents the inner core from oxidation by forming a compact quartz glass coating at the surface under high temperature. The temperature generated by MoSi2 goes as high as 1700~1800℃ in oxidation atmosphere. They can be widely used in such applications as sintering and heat treatment on electronic ceramics, structural ceramics, magnetic materials, flameproof materials, glass, metallurgy, etc. The resistance of the heating elements is independent on their mission time. The MoSi2 heating elements hardly age, which allows the mixed use of new and old packages.
Packaging is available in U shape, W shape, Straight shape (X shape) and bend shape (L shape),etc. The dimension ranges from 3/6, 4/9, 5/10, 6/10, 6/12, 6/14, 7/14, 8/16, 9/18 to 12/24mm. Special request from customers is welcome.
Having the same mechanical character as other ceramic products. The Yuhao MoSi2 Heating Elements belong to the brittleness material so that they are easy to rupture at the normal temperature ,which brings some difficulty to transport and install, but it may be avoided if they were installed and used correctly.
2. Physical and Chemical Properties of Elements
1) Physical property
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Volume density
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5.5～5.6kg/cm3
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Bend strength
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515～25kg/cm2
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Vickers-hardness
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(HV)570kg/mm2
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Porosity rate
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7.4%
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Water absorption
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1.2%
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Hot extensibility
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4%
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2) Chemical property
Oxygen-resistance under high temperature: in oxidizing atmosphere,on the surface of element owing to the high-temperature combustion a layer of compact quartz(sio2)protective film is formed to prevent Mosi2 from continuously oxidizing.When the element temperature is higher than 1700℃,the sio2 protective film, Whose fusing point is 1710℃, is fused,and the sio2 is fused into molten drops owing to the action of its surface extension, so that loses its protective ability,In the oxidizing atmosphere,when the element is continuously used,again the protective film forms.
It should be pointed out that element cannot be used for rather long time in 400-700℃, or it will be powdered owing to the strong oxidizing action in low temperature.