Melting Peaks of Metal Alloys

When analyzing modern metal alloys, it is important that there be a good separation of the melting peaks for the individual alloy components. The DSC 204 F1 Phoenix® with τ-Sensor yields an excellent Peak Separation in the melting range from 510°C to 650°C for the aluminum alloy measured here.

Without Corrosion to the Highest Temperatures!

Tungsten is a metal very sensitive to oxidation. But due to the vacuumtight design of the Expedis Supreme the material can be measured in pure He atmosphere (in combination with OTS® – Oxygen Trap System) to get its true expansion behavior. There is no need of reducing atmosphere to suppress superficial oxidation (which would change the color of the sample).

In the present experiment, the calculated mean CTE value between 20°C and 1500°C results in 5.143 x 10-6 1/K and thus differs just 1.4 x 10-8 1/K from the mean CTE of 5.129 x 10-6 1/K which is based on theoretical data (NIST standard table).

Thermal behavior of tungstenThermal behavior of tungsten, sample length: 25.00 mm, heating rate: 5 K/min, He atmosphere, constant contact force: 250 mN, alumina sample holder. Displayed are the length change of the sample (black solid line) together with the tabulated theoretical data (red dashed line, NIST standard table).

Thin and Highly Conductive Copper

This plot shows measurements on copper samples with different thicknesses.It clearly proves that the system can successfully measure samples with very high diffusivities. In addition, by decreasing the sample thickness from 3.0 mm to 0.25 mm, these measurements confirm that even very thin samples can be tested with very high accuracy. Sample preparation and thickness determination have to be carefully considered when measuring thin samples. This is the reason that the uncertainty increases as sample thicknesses decrease.

Thermal diffusivity values for the copper samples are in very good accordance with literature data, irrespective of the sample thickness.Thermal diffusivity values for the copper samples are in very good accordance with literature data, irrespective of the sample thickness.

Thermal Diffusivity of Bio-Alumina

This figure shows the LFA-measuring results of thermal diffusivity measurements at a sample body from Bio-Alumina with graphite coating on both sides. The measurement results from two different laboratories (KfK x Research Center Karlsruhe, IMF1 and LFA 427 + NETZSCH Applications laboratory) do agree very well.

Evolved Gas Analysis (QMS) of Lead Chloride

Lead chloride (7.92 mg) in an argon flow of 150 ml/min shows evaporation starting in the melting range (487°C). The molecule ion (PbCl2 m/z = 278) and fragment ions caused by dissociation and ionization (PbCl m/z = 243, Pb m/z = 208, Cl m/z = 37, CL m/z = 35) are clearly detected far below the boiling temperature of the starting material. (measurement with QMS 403/5 SKIMMER®)

Sintering of Aluminum Titanate

One use of aluminum titanate is as a carrier material for catalytic converters in the automobile industry. Shown here is the measurement of an aluminum titanate green body in the temperature range from RT to 1450°C with a subsequent isothermal line at 1450°C of 7 hours. During the heating, shrinkage of 12.7% is observed. The sintering takes place in 2 steps with a maximum sintering rate of 0.31%/min. In the subsequent isothermal phase, further shrinkage of 0.6% occurs. To optimize the sintering process, an RCS measurement (rate controlled sintering; optionally available) can additionally be carried out. (measurement with TMA 402 F1/F3 Hyperion®)

Specific Heat Determination of Alumina

Presented in the figure is a specific heat test result for a polycrystalline alumina sample between room temperature and 1600°C. Additionally shown are literature values for pure alumina. It can clearly be seen that there are no significant differences between the literature values and the test results. The maximum deviations are in the range of 2%, which demonstrates the outstanding performance of the DSC 404 F1 Pegasus®.

Phase Transitions of Steel Material

Presented here are the transformation energetics of a steel (SAE 107). At 751°C, two phase transitions overlap each other. The increase in the heat flow rate up to 735°C is due to the Curie transition (change in the magnetic properties). A change in the crystal structure (bcc to fcc structure) is causing the major peak. The structural change is connected with an enthalpy change of 63 J/g. Melting was seen at 1367°C and occurred in two steps (peaks at 1395°C and 1471°C). The heat of fusion was 268 J/g. (measurement with DSC 404 F1 Pegasus®)

Melting & Solidification of Aluminum Alloy

Two different samples of aluminium alloy (Al-Mg-Si) were measured with the DSC 404 F3 Pegasus® during heating and cooling. Melting and also solidification of the alloy is clearly visible in the measurement results. The differences between the two different samples, however, are small. The characteristic temperatures (onset, peak) agree all within 0.3 K. The differences in the peak areas are less than 1% for both heating and cooling. The good agreement between the two measurement results demonstrates the excellent capability and reproducibility of the DSC 404 F3 Pegasus®.

Thermal Expansion of Iron

This figure depicts the linear thermal expansion and physical coefficient of thermal expansion (physical CTE) of iron. The sample was measured at a heating rate of 5 K/min in a helium atmosphere. At 906°C (peak temperature in the physical alpha) a shrinkage step was detected. This is due to a change in the lattice structure (bcc -> fcc). Another change in the lattice structure (fcc -> bcc) was detected at 1409°C. The deviation between the measured and literature transition temperatures is due to a small impurity content. (measurement with DIL 402 C)