Ceramic & Glass

  • What is the quartz content in the ceramic raw material?
  • How changes the reactivity of the nano material?
  • With what sintering rate can the best sinter density be achieved?
  • What hydrate phases does gypsum have under a saturated steam atmosphere?
  • At what temperature is the curing of the adhesive completed?
  • How high is the mass loss during the dehydration of the ceramic mass?


These or similar questions can be answered with modern thermoanalytical measuring techniques.

Knowing the thermal extension coefficient for the sintering of technical ceramics, phase transitions and specific heat, modified glass or the precise thermal conductivity values of inorganic building materials is of high practical importance.

One can glean information about phase transformations, changes in specific heat, exact thermal conductivity values, the sintering behavior of ceramic materials and practice-relevant mechanical properties of refractories from the most varied of measuring methods.

 


Recommended literature:

Recommended literature:

Scientific Publications

Scientific Publications

Further scientific publications are to be found HERE.

Detailed Insight Into the World of Thermal Analysis

Detailed Insight Into the World of Thermal Analysis

Simultaneous Thermal Analysis (STA) is ideal for investigating issues such as the glass transition of modified glass, binder burnout, dehydration of ceramic materials or decomposition behavior of inorganic building materials, also with evolved gas analysis (EGA).

The expansion and shrinkage behavior of technical ceramics during sintering can be measured with dilatometry.

LFA, HFM and TCT are versatile methods for the precise determination of thermal conductivity.

For refractories, important mechanical values such as bending strength at elevated temperatures, softening under load, and creep in compression can be measured.

Some Application Examples

Some Application Examples

Low Thermal Expansion for High Shock Restistance

Borosilicate are well known for those characterisitic properties. In addition, these glasses have excellent optical, chemical and mechanical properties which allow for high quality products such as implantable medical devices and devices used in space exploration. This plot shows the thermal expansion of a borosilicate glass between room temperature and 700°C. Glass transition was determined at 528°C (extrapolated onset), softening of the glass occurred at 631°C.

Thermal Conducitvity of Mineral Fiber Insulation

A mineral fiber insulation generally used to insulate kitchen furnaces was measured between room temperature and 500°C. As it is typical for most insulating materials, the results for the thermal conductivity increase in a nearly linear fashion around room temperature. At high temperatures, the thermal conductivity increases more markedly. This can be explained by the increased radiative contribution to the effective thermal conductivity. (measurement with GHP 456 Titan®)

Prevention of Glas Crazing

Poor glaze/body fit is the main cause of crazing (spider web pattern of cracks penetrating the glaze). This effect is caused by, e.g., thermal expansion mis-match. To prevent crazing, the thermal expansion of the glaze must be less than that of the body. This plot shows the expansion behavior of the glaze (red curve) compared to that of the body to which it should be applied. At 700°C – shortly before the glass transition temperature of the glaze at 718°C – the difference in expansion amounts to 0.02%. Softening of the glaze occurs at 822°C. The higher expansion of the glaze could lead to unwanted tensile stress during cooling which is proportional to the thermal expansion.

Comparison of the thermal expansion of a glaze and the body on which it should be held. α → β-transition of quartz is detected at 575°C, shown here in the 1st derivate of the body (blue dotted curve). Measurement condition: heating rate 5 K/min, airComparison of the thermal expansion of a glaze and the body on which it should be held. α → β-transition of quartz is detected at 575°C, shown here in the 1st derivate of the body (blue dotted curve). Measurement condition: heating rate 5 K/min, air atmosphere.