High-Temperature Instrument Performance: Why a Combination of DSC, LFA, and DIL Provides Deeper Insight

The Secrets of High-Temperature Instrument Performance

At NETZSCH, we know that an overall picture of a material's high-temperature behavior goes beyond a single test. That is why we help you combine Differential Scanning Calorimetry (DSC), Laser Flash Analysis (LFA), and Dilatometry (DIL). Together, these methods provide a 360-degree view of how materials respond to heat, from how they absorb and release energy to how they conduct it - and how their dimensions change with temperature.

Here’s why this trio of techniques is invaluable for anyone involved in designing, testing, or using materials for high-temperature applications.

Why Use DSC, LFA, and DIL in Combination?

1. DSC: Revealing Thermal Transitions

Differential Scanning Calorimetry (DSC) measures how a material’s heat flow changes as it’s heated or cooled. For high-temperature applications, DSC provides critical insight into Phase TransitionsThe term phase transition (or phase change) is most commonly used to describe transitions between the solid, liquid and gaseous states.phase transitions (such as melting, CrystallizationCrystallization is the physical process of hardening during the formation and growth of crystals. During this process, heat of crystallization is released.crystallization, etc.), reaction enthalpies, and specificheat capacity. For example:

• Phase transitions: By revealing phase changes like melting or CrystallizationCrystallization is the physical process of hardening during the formation and growth of crystals. During this process, heat of crystallization is released.crystallization, DSC helps engineers understand when and how a material may lose stability or change properties under heat.
• Specific Heat Capacity (cp)Heat capacity is a material-specific physical quantity, determined by the amount of heat supplied to specimen, divided by the resulting temperature increase. The specific heat capacity is related to a unit mass of the specimen.Specific heat capacity: Knowing how much energy a material absorbs is essential for thermal management because it affects cooling and heating requirements in practical applications.

For materials that are expected to survive and perform at temperatures of 1000°C or more, these insights are fundamental. But DSC alone doesn't tell the whole story.

2. LFA: Measuring Heat Transfer Efficiency

While DSC explains how much heat a material absorbs or releases, Laser/Light Flash Analysis (LFA) examines how well it conducts that heat. This is key for applications where heat transfer affects performance and safety, such as in electronics, engines, and insulation materials.

The LFA technique provides Thermal DiffusivityThermal diffusivity (a with the unit mm2/s) is a material-specific property for characterizing unsteady heat conduction. This value describes how quickly a material reacts to a change in temperature.thermal diffusivity and Thermal ConductivityThermal conductivity (λ with the unit W/(m•K)) describes the transport of energy – in the form of heat – through a body of mass as the result of a temperature gradient (see fig. 1). According to the second law of thermodynamics, heat always flows in the direction of the lower temperature.thermal conductivity values, indicating:

• Heat transfer: High Thermal ConductivityThermal conductivity (λ with the unit W/(m•K)) describes the transport of energy – in the form of heat – through a body of mass as the result of a temperature gradient (see fig. 1). According to the second law of thermodynamics, heat always flows in the direction of the lower temperature.thermal conductivity materials, such as certain metals, are ideal for rapid heat dissipation, while low conductivity materials, such as some ceramics and polymers, are ideal for insulation.
• Temperature-dependent behavior: For many materials, conductivity changes with temperature, and knowing how this occurs helps engineers in designs for both steady and fluctuating thermal environments.

LFA data is especially useful when paired with DSC to provide context on Phase TransitionsThe term phase transition (or phase change) is most commonly used to describe transitions between the solid, liquid and gaseous states.phase transitions, as these often coincide with shifts in Thermal ConductivityThermal conductivity (λ with the unit W/(m•K)) describes the transport of energy – in the form of heat – through a body of mass as the result of a temperature gradient (see fig. 1). According to the second law of thermodynamics, heat always flows in the direction of the lower temperature.thermal conductivity.

3. DIL: Understanding Dimensional Stability

Dilatometry (DIL) completes the trio by measuring how a material expands or contracts as it heats up or cools down. This thermal expansion data is essential for designing components that are exposed to variable temperature conditions. At high temperatures, a material's ability to remain dimensionally stable affects everything from its fit in an assembly to its resistance to thermal shock.

DIL data can reveal:

• Coefficients of thermal expansion: Knowing how much a material expands or contracts with temperature can prevent problems such as cracking, warping, or component failure.
• CreepCreep describes a time and temperature dependent plastic deformation under a constant force. When a constant force is applied to a rubber compound, the initial deformation obtained due to the application of the force is not fixed. The deformation will increase with time.Creep and RelaxationWhen a constant strain is applied to a rubber compound, the force necessary to maintain that strain is not constant but decreases with time; this behavior is known as stress relaxation. The process responsible for stress relaxation can be physical or chemical, and under normal conditions, both will occur at the same time. relaxation: Materials exposed to prolonged heat may exhibit slow deformation (CreepCreep describes a time and temperature dependent plastic deformation under a constant force. When a constant force is applied to a rubber compound, the initial deformation obtained due to the application of the force is not fixed. The deformation will increase with time.creep), which can compromise durability.

This data is critical for designers, especially in applications that combine materials with different expansion behavior, such as electronics or multi-layer composites.

The Benefits of Using All Three Techniques Together

• Complementary High-Temperature Profile
  
  Using DSC, LFA, and DIL together allows for mapping the complementary high-temperature behavior of a material. For example, while DSC detects a Phase TransitionsThe term phase transition (or phase change) is most commonly used to describe transitions between the solid, liquid and gaseous states.phase transition, LFA can show whether that change affects Thermal DiffusivityThermal diffusivity (a with the unit mm2/s) is a material-specific property for characterizing unsteady heat conduction. This value describes how quickly a material reacts to a change in temperature.thermal diffusivity and conductivity, and DIL can confirm whether it affects the shape of the material. This combined approach gives engineers and researchers an in-depth profile of a material's thermal and dimensional stability under real-world conditions.
  
  
• Enhanced Design and Performance Optimization
  
  Industries requiring high-performance materials benefit from knowing both the thermal and mechanical properties at high temperatures. By integrating DSC, LFA, and DIL data, companies can optimize their processes. For example:
  • Automotive and Aerospace: Parts exposed to extreme temperatures can be designed for both heat resistance (DSC/TG/LFA) and dimensional stability (DIL).
  • Power Generation and Insulation: Thermal management becomes more efficient when Thermal ConductivityThermal conductivity (λ with the unit W/(m•K)) describes the transport of energy – in the form of heat – through a body of mass as the result of a temperature gradient (see fig. 1). According to the second law of thermodynamics, heat always flows in the direction of the lower temperature.thermal conductivity and expansion are tailored to specific applications.
    
    
• Improved Product Lifetime and Safety
  
  By characterizing a material's response across multiple thermal measurements, the combination of DSC, LFA, and DIL enables proactive design for durability and reliability. Materials can be selected or designed to maintain their properties over prolonged exposure to high temperatures, reducing the risk of material failure.

Practical Applications of DSC, LFA, and DIL in High-Temperature Analysis

The combination of these techniques opens new doors in areas such as

• Ceramics and Glass: Thermal expansion and stability are critical in refractory materials, that require high Thermal StabilityA material is thermally stable if it does not decompose under the influence of temperature. One way to determine the thermal stability of a substance is to use a TGA (thermogravimetric analyzer). thermal stability (DSC/TG) and low conductivity (LFA) with consistent size and volume (DIL) at high temperatures.
• Metal Alloys: The usage of metals in engines or reactors benefits from a combination of high Thermal ConductivityThermal conductivity (λ with the unit W/(m•K)) describes the transport of energy – in the form of heat – through a body of mass as the result of a temperature gradient (see fig. 1). According to the second law of thermodynamics, heat always flows in the direction of the lower temperature.thermal conductivity (LFA) and stable phase behavior (DSC), with controlled expansion (DIL) to prevent StressStress is defined as a level of force applied on a sample with a well-defined cross section. (Stress = force/area). Samples having a circular or rectangular cross section can be compressed or stretched. Elastic materials like rubber can be stretched up to 5 to 10 times their original length.stress fractures.
• Composites: Materials used in electronics or aerospace applications require optimized heat dissipation (LFA) without phase shifts (DSC) or size changes (DIL) that could lead to circuit or assembly issues.

Learn more about NETZSCH analysis instruments for high-temperature applications:

• 
  DSC 404 F1 Pegasus^®

  The high-temperature Differential Scanning Calorimeter

  • Temperature range: from -150°C up to 2000°C
  • Integrated metal-housed mass flow control systems (MFC) for three different gases
  • Optional temperature modulation (TM-DSC)
• 
  LFA 717 High Temperature HyperFlash^®

  A fast and non-contact method for determining Thermal DiffusivityThermal diffusivity (a with the unit mm2/s) is a material-specific property for characterizing unsteady heat conduction. This value describes how quickly a material reacts to a change in temperature.thermal diffusivity up to 1250°C

  • Long-life xenon lamp for cost-effective operation of measurements up to 1250°C
  • Vacuum-tight platinum furnace for heating rates up to 50 K/min
  • Mini-tube furnaces for unmatched test speed.
• 
  DIL 402 Expedis^® Supreme HT
  • Temperature Range: -180°C to 2800°C
  • ΔL Resolution over the entire measuring range: 0.1 nm