Method and device for correcting temperature of thermal mechanical analyzer tensile fixture

Abstract

The invention discloses a method and device for correcting temperature of a thermal mechanical analyzer tensile fixture. According to the method, a metal sample with a known melting point is fixed in a sample support of the tensile fixture, a probe is made to be in direct contact or indirect contact with the sample, when the sample is heated to be in a melting state, the probe can induct the sudden change of displacement, the temperature of the sample at the moment is measured through a thermocouple, and the temperature value and the actual melting point of the sample are compared and analyzed so that temperature correction can be carried out. Before a tensile mode is carried out by a thermal mechanical analyzer, temperature correction is carried out on the thermal mechanical analyzer with the metal sample with the known melting point, temperature parameters can be more accurate when the tensile mode is carried out, and the fact that the testing result of the tensile mode is more accurate is guaranteed.

Description

technical field [0001] The invention relates to the technical field of thermomechanical analyzers, in particular to a temperature correction method and device for a tensile fixture of a thermomechanical analyzer. Background technique [0002] Thermomechanical analysis TMA (Thermo mechanical analysis) is a technique to measure the relationship between the dimensional change of the sample and the temperature (or time) under the set atmosphere, load and temperature program. The instruments used for this measurement are called thermomechanical analyzers. [0003] Among the various modes of thermomechanical analysis, expansion mode and tension mode are commonly used, and different fixtures are used to process samples corresponding to different modes. [0004] When using the expansion mode, the expansion fixture 100 is installed in the heating furnace of the thermomechanical analyzer, and the structure of the expansion fixture 100 is as follows figure 1 As shown, it includes a s...

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Problems solved by technology

[0009] In the prior art, there is only the temperature correction method of the TMA expansion fixture. When measuring in the tension mode, the correction temperature parameters in the expansion mode are quoted. There is no correction method specifically for the tension mode, which will make the thermomechanical analyzer in the The following defects occur when testing samples in tensile mode:

[0010] (1) Due to the uneven temperature (temperature gradient) in the TMA heating furnace, after the expansion fixture is replaced with a tensile fixture, the relative position of the sample-thermocouple-furnace changes and the difference in heat conduction at different positions of the furnace will cause the original The temperature correction parameters obtained by calibration under the expansion fixture are not applicable, the test temperature of the sample deviates from the actual value, and the test result is incorrect;

[0011] (2) After changing to tensile mode, in order to minimize the temperature test error, the thermocouple position is generally placed in the tensile mode sample holder close to the sample, but in some models of TMA design, the thermocouple will block The action of the probe when the probe displacement is cleared before the test

This will bring a problem: that is, the relative position between the thermocouple and the sample may not be fixed for each test, and the stability of the temperature test results is poor.

There is another situation: the placement of thermocouples near the sample may hinder the expansion or contraction of the sample during the test, resulting in inaccurate test results

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