Coefficient of thermal expansion

The coefficient of thermal expansion is a fundamental parameter for evaluating the behavior of a material when subjected to temperature variations. It expresses the elongation, contraction, or dimensional deformation of a material as a function of a thermal change. This data is essential for materials used in sensitive environments, subjected to thermal cycling, or under significant mechanical stresses. It plays a direct role in the design, engineering, modeling, and qualification of technical products such as plastics, composites, ceramics, metals, and packaging materials.

Importance of the measurement

Thermal expansion can influence a product's performance, durability, and safety. When several materials with different coefficients are assembled, internal stresses can occur, leading to cracks, delamination, deformation, or breakage. Accurate knowledge of the coefficient of thermal expansion makes it possible to: avoid incompatibilities between materials, correctly dimension mechanical parts, guarantee dimensional stability in fluctuating environments, and predict the effects of aging, storage, or exposure to repeated thermal cycles. This information is essential in the plastics, composite materials, aerospace, automotive, electronics, packaging, and industrial equipment sectors.

Analytical methods

The coefficient of thermal expansion can be measured using several complementary techniques.
Thermomechanical analysis (TMA) measures the dimensional changes of a sample subjected to a controlled temperature ramp. It offers high accuracy for polymers, films, flexible materials, and composites.
Dilatometry, the reference method, directly measures the elongation or contraction of a material as its temperature increases. It is particularly well-suited to rigid materials such as metals, glasses, ceramics, and engineering polymers.
Pycnometry can be used as a complement to determine the density before and after thermal exposure, allowing for the evaluation of certain heat-influenced structural properties.
These combined methods provide a comprehensive characterization of the thermal behavior of a material, regardless of its nature.

Analyzed matrices

This analysis applies to a wide range of materials used in numerous industrial sectors: plastics, fibrous composites, elastomers, packaging materials, engineering resins, ceramics, glasses, metal alloys, industrial foams, technical films, recycled or bio-based materials. The measurement is relevant for raw materials as well as finished parts, prototypes, assembled materials, and hybrid structures. It assists manufacturers in validating their formulations, evaluating the actual behavior of a material, and selecting solutions adapted to specific thermal constraints.

Interest for professionals

For manufacturers, materials engineers, processors, and design offices, measuring the coefficient of thermal expansion is a strategic tool for designing strong and reliable parts. It allows them to understand the impact of temperature on performance, adjust manufacturing processes (molding, extrusion, assembly), prevent mechanical failures, and improve product durability. In electronics and packaging, it guarantees the integrity of components subjected to thermal cycling. In composites, it helps anticipate delamination and differential expansion. This data is therefore essential for ensuring material compatibility and optimal performance.

YesWeLab Expertise

YesWeLab collaborates with expert laboratories specializing in thermal, mechanical, and physicochemical analysis of materials. The majority of our partners are certified or accredited (ISO 17025, COFRAC), ensuring optimal reliability of results. Depending on your material and technical requirements, our team identifies the most appropriate method—TMA, dilatometry, or pycnometry—and provides comprehensive management of your analyses. Our digital platform facilitates the sending, tracking, and receipt of results, while offering you tailored scientific support.

Other relevant analyses from the YesWeLab catalogue

• Thermal analysis (DSC, TGA)
• FTIR characterization of polymers
• Mechanical tests (tensile, compression, flexural)