Research & Development - Quality
Control - Failure Analysis
Accuracy: Polycrystalline Alumina
Presented in the figure is a comparison
of three test runs (lines) on a polycrystalline alumina (aluminum
oxide) with the corresponding literature values (crosses) between
room temperature and 1575°C. No visible deviations exist between
the individ-ual curves. Evaluation of the ther-
mal expansion values at 500, 1000 and 1500°C clearly shows that the measurement
results are within 1% of the corresponding literature values. This tests
proves the outstand-ing reproducibility and accuracy of the new dilatometer.
Glass
Coefficients of thermal expansion
(CTE), glass transition temperatures and softening points are
crucial parameters for the characterization of glass materials.
Presented in the fig-ure are three tests on same type of glass
but from different batches. It can clearly be seen that the coefficients
of thermal expansion are in good agreement within the instrument’s
uncertainty boundaries. The glass transition temperature and
the softening point of sample #3 (blue curve) show slightly lower
values, indicating a slightly different composition.
Sintering of Zirconia
During the production of high-tech
ceramics, a ceramic powder is mixed with a binder and pressed
to a green body. By thermal treatment the binder is removed (burned
out) and the ceramic is sintered to the final part. In order
to determine the quality of the final part, the binder burnout
and sintering temperatures as well as the shrinkage during sintering
have to be known. These properties can be measured quickly and
easily using pushrod dilatometry. Presented in the figure are
tests on an yttria-stabilized zirconia green body and on the
sintered ceramic.
Production of Cordierite ceramic
Cordierite is a popular magnesia-alumina-silica
ceramic used in various kinds of industrial applica-tions. It
is used, for example, as a carrier for catalysts in the automotive
industry. During the production of this ceramic, various raw
materials are ground and mixed to form a green body. During firing
under oxidizing atmospheres, the organic additives are burned
out and the cordierite phase is formed at high temperatures.
Using the DIL 402 PC in combination with the c-DTA software,
the production process can be analysed in detail.
NETZSCH offers
precision thermal analysis instruments including advanced dilatometers (with
a new basic R&D/QC dilatometer),
classical DSC & TGA (with
a new economical DSC), high temperature DSC
to 1650°C for specific heat, very high temperature STA
(TGA-DSC/DTA) to 2400°C (featuring the new STA
409-PC Luxx®), thermal
/ evolved gas analysis with fully-integrated FTIR & MS, plus
high resolution TMA and DMA.
We also feature leading technology for thermal conductivity and diffusivity measurement
as well as refractories testing including HMOR, CIC, and RUL.
