TMA Analysis | EUROLAB

What Is TMA Analysis?

Thermomechanical analysis involves applying a small constant or variable force to the sample while changing temperature in a programmed manner and measuring dimensional change. The resulting curve shows the material's thermal expansion behaviour and transition temperatures.

Purpose of TMA Analysis

The purpose is to measure how a material's dimensions change with temperature. The coefficient of thermal expansion, glass transition temperature, softening point and delamination behaviour are read from this measurement. This data underlies design in structures combining materials with different expansion coefficients.

Which Products Is TMA Analysis Applied To?

Printed circuit boards and laminates
Engineering plastics and composites
Adhesive and encapsulation materials
Glass, ceramic and coating materials
Film and fibre materials

In Which Sectors Is TMA Analysis Used?

ElectronicsPlasticsAutomotiveAerospaceCeramics

Standards Related to TMA Analysis

ISO 11359-2 (thermomechanical analysis of plastics — expansion coefficient and Tg)
ASTM E831 (linear thermal expansion by TMA)
IPC-TM-650 2.4.24 (Tg and expansion in laminates)

TMA Analysis Conditions

Temperature range: Including the usage and transition temperatures of the material; defined in the method
Heating rate: The method is specified in the standard; directly affects the result
Uygulanan kuvvet: By measurement mode (expansion, penetration, tension)
Atmosfer: Generally inert gas flow

Equipment for TMA Analysis

Thermomechanical analyser
Expansion, penetration and tension probes
Temperature-controlled furnace and cooling unit
Calibration reference materials

Sample Requirements for TMA Analysis

Sample surfaces must be parallel and flat
Dimensions must suit the instrument's sample holder
Film and fibre samples must be cut to a length suitable for the tension probe
The sample's thermal history (curing, annealing) must be stated — it affects the result

Duration of TMA Analysis

A measurement is generally completed within one to a few hours. Duration extends if repeated heating cycles are requested.

TMA Analysis Procedure

1The sample is measured and placed in the sample holder.
2The probe is brought into contact and the initial length recorded.
3The defined heating programme is applied.
4Dimensional change is recorded against temperature.
5The expansion coefficient and transition temperatures are calculated from the curve.
6Repeated with a second heating if required, eliminating the effect of thermal history.

TMA Analysis Acceptance Criteria

Acceptance values for expansion coefficient and Tg come from the material specification or laminate class definition.

Evaluation of Results

Heating rate and applied force significantly affect the result, so results from different laboratories are comparable only with the same method parameters. The first heating curve also carries the material's thermal history, so most methods take the second heating as the basis.

TMA Analysis Report

Sample description, receipt date and laboratory number
Method applied and reference standard, if any
Instrument and measurement conditions
Sample preparation steps
Measurement results and units
Measurement uncertainty (if requested)
A statement that the results relate only to the sample submitted for testing

Accreditation

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

Scope and authorisations

Related Regulations

IPC specifications for electronic board materials
Aviation composite material acceptance specifications

Pages Where This Method Is Used

Analytical Methods — What Does This Group of Methods Do?

The section below describes the field that the TMA Analysis test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

Analytical method pages are pages about a MEASUREMENT TECHNIQUE rather than about a test. The difference matters: "salt spray testing" is a test and answers one question; "ICP-MS" is a technique and is used in dozens of different tests. Sometimes the user is looking not for the test but for the technique — because the method name is what appears in their specification.

This distinction becomes decisive in choosing a laboratory. When a customer asks for "heavy metal analysis", the real question is by which technique it will be done: XRF is fast and non-destructive but does not distinguish compounds; AAS is economical for a single element; ICP-OES screens multiple elements; ICP-MS sees trace levels. The same sample gives results with different detection limits and different uncertainties across the four techniques.

Method selection is made against three criteria. DETECTION LIMIT: is the concentration sought within the range the method can see? MATRIX COMPATIBILITY: is the sample matrix (plastic, food, soil, metal) one the method can handle, and is pre-treatment required? SPECIFICATION LINK: does the product standard or legislation mandate a particular method? The third often overrides the first two — the specification binds the method.

Method pages build a CHAIN. A technique is linked to the test pages where it is used, to the standards those tests rest on, to the legislation those standards are tied to and ultimately to market access regimes. The example chain in the source document works like this: XRF → metal analysis → RoHS compliance → heavy metal restriction → coating pages. Whichever link the user enters from, they reach the others.

Sample preparation is the invisible half of the result in this family and is a greater source of error than the technique itself. The digestion method, degree of grinding, extraction solvent and dilution ratio change the result markedly. The same sample on the same instrument gives a different result with different preparation; the definition of the method therefore covers preparation too.

Calibration and verification are the third determining component. An instrument is calibrated with certified reference material, the calibration curve is verified periodically and a control sample is run in each batch. Without these steps, a number produced is not traceable even if the instrument is working correctly.

Method groups in this field

Elemental analysis
ICP-OES, ICP-MS, AAS and XRF. They differ in detection limit, matrix tolerance and multi-element capacity.
Chromatography
GC, GC-MS, HPLC, LC-MS/MS and ion chromatography. It separates a mixture into its components and measures each separately.
Spectroscopy
FTIR, Raman, UV-Vis and optical emission. For material identity, functional group identification and alloy composition.
Thermal analysis
DSC, TGA, DMA and dilatometry. Transition temperatures, composition, decomposition and dimensional behaviour.
Microscopy and imaging
Optical microscopy, SEM-EDS, radiography and tomography. Structure, defects and elemental distribution.
Classical (wet) chemistry
Titration, gravimetry and colorimetry. Used as a reference method and in confirming instrumental results.

Commonly confused in this field

XRF is a screening tool; it sees elements and does not distinguish compounds. A decision on a restricted compound requires confirmation by wet chemistry.
The phrase "not detected" is not proof of absence; it is read together with the detection limit of the method.
The specification binds the method. A technically better method is not accepted if the specification calls for another.
Sample preparation is part of the result; a report that does not state the preparation is not reproducible.
Results obtained by different techniques cannot be compared directly; their detection limits and uncertainties differ.
A method page is not a test page; which method applies to which test comes from the product standard.

Which decisions these results support

Matching the method written in the specification to the laboratory's scope
Method selection according to detection limit and matrix compatibility
Confirming an instrumental result with a reference method
Eliminating deviations arising from sample preparation

Related Tests

Frequently Asked Questions About TMA Analysis

What is the difference between TMA and DMA?

TMA measures dimensional change under constant force. DMA applies an oscillating force to give storage and loss modulus; DMA is more sensitive for determining glass transition.

Why does Tg differ between methods?

Glass transition is not a single temperature but a range. DSC, TMA and DMA monitor different physical quantities and therefore give different values; the report must state which method was used.