TAL offers specialized expertise in thermal expansion testing services. Thermomechanical Analysis (TMA) is a technique used to determine the dimensional changes of a sample with respect to temperature, such as the softening temperature, glass transition temperature, and coefficient of linear thermal expansion (CTE). The most common application of TMA is to determine the CTE.
CTE is defined as the degree of expansion divided by the change in temperature:
Where ΔL is the change in length, L0 is the initial length, and ΔT is the change in temperature.
Understanding the CTE of a material is essential for proper usage in different environmental conditions. Failure to account for CTE in certain applications can introduce detrimental stress and ultimately lead to failure. A precise understanding of thermal expansion behaviour provides crucial insight into firing processes, the influence of additives, reaction kinetics, and other important aspects of how a material responds to environmental changes.
TAL offers Thermomechanical analysis testing using Rigaku TMA 8311- the first TMA to offer differential methods. This extremely precise system offers a temperature range of -70°C to 1500°C, and multiple attachments are available to conform to specific testing needs. TAL currently offers single rod & differential compression loading (expansion, shrinkage, glass transition) and differential penetration (softening).
For more information on the theory of how to measure CTE, click here.
Application 1: Uncerstanding Ceramics
Comparison of a ceramic’s thermal expansion before and after firing gives insight into its behaviour across a range of temperatures. This data is valuable in refining the firing process, and understanding how materials perform in high temperature applications.
Below: The unfired raw ceramic (white) undergoes a variety of complex irreversible changes (x) such as diffusion, water expulsion, chemical reaction and sintering, as well as reversible overall thermal expansion. In contrast, the fired ceramic (blue) exhibits only thermal expansion and a phase transition (O) at 552°C, demonstrating the overall effects of firing and the resulting fired ceramic’s thermal expansion behavior.
Application 2: Understanding Ceramic Glazes
Glazing is a critical process in the final production of ceramics, from capacitors to cookware. To ensure a properly glazed ceramic, the Coefficient of Thermal Expansion (CTE) must be considered for both the glaze and the base ceramic. Ideally, the glazing exhibits a slightly lower CTE than the ceramic to facilitate a tight lamination. A larger glaze CTE can result in cracking and a weaker finished product, due to a CTE mismatch between the glaze and substrate.
Below: a ceramic glaze (white) was heated through its glass transition point (Tg) at 785°C and to its softening point (894°C). The resulting CTE (blue) is calculated and displayed on the right y-axis.
Application 3: Measuring the Glass Transition Temperature of Polymers
The glass transition temperature is a critical polymer property which defines when the polymer transitions from a hard, glassy state to a softer, more rubbery state. It is used in defining use cases for polymer products and in process and product design. The glass transition temperature is visible as a change in the slope of a TMA plot, sometimes with an evident relaxation.
Below: A piece of polyethylene terephthalate (PET) is heated through its glass transition temperature. The two-line method is used to determine the glass transition temperature.
|Temperature Range||-70°C – 1500°C|
|Maximum Heating Rate||100°C/min (20°C/min for low temperature furnace)|
|Length Change Resolution||0.3nm|
|Differential and Non-Differential Compression Loading||L = 10-20mm, D = 5mm (up to 9mm)|
|Differential Penetration||L ≤ 4mm, D ≤ 5mm|
|Tensile Loading Attachment*||L ≥ 30 mm, W ≤ 30 mm, T = 0.01-0.2 mm|
* Maximum temperature limitations apply for this test configuration.
I was well pleased with the experience. The instructions for the sample configuration was clear. The people responded promptly to questions. The lab double checked results to address any questions. The report was clear, easily understood.
Vice President of Technology
I am very happy with the testing services I received from Thermal Analysis Labs. I’ve found them very responsive, and they were able to get us the data we needed to get quickly so that we could use it to validate our designs. I refer my other colleagues to them, and they’re my go-to group for thermal testing.
Scott Kramer, PEng.,
Principal R&D Engineer
I sought thermal conductivity testing from Thermal Analysis Labs to aid in device design. My group has experienced good customer service with speedy sample processing and fast turnaround time. I would be happy to recommend this group to anyone looking for this service.
Project & Supply Chain Manager
I’ve outsourced thermal testing of several materials to TAL. My experience has been very positive. Their professionalism shows in management, quality of work, and customer service. They are always eager to accommodate my needs and timeline. I highly recommend their services.
Thermodynamics and CFD Group Manager
All data and reports were very helpful and we appreciate your support; you did an amazing job to conduct the tests and confirm the reports within such a short time frame. This really helped us get out of jam and your support meant a lot to our efforts with our customer. We will certainly contact you again on these matters.
Thermal Analysis Labs has provided great service for all our materials testing needs by providing quick turn-around testing results while also providing the service for a reasonable cost. TAL’s professional approach to our material testing request has also provided great insight to the materials being tested and the best method to achieve the measurements. TAL has been an invaluable resource for our product development process.
Fellow Engineer, Advanced Concepts
I had a request for thermal conductivity information on one of my adhesives and contacted Thermal Analysis Labs. The process was very smooth – I experienced none of the issues typical of other contract labs we work with. The results were delivered on time and I have used the data in our sales literature to help my clients have success in their applications.
Vice President of Sales
I was completely satisfied with the testing experience.
Vice President of Technology