Characterization of Composites | Bruker

Localized Mechanical Property Characterization of Composites

Manufacturing and researching composite materials comes with a host of interesting and challenging problems. Reinforcement and matrix materials often have significant differences in their material properties that affect the behavior of the composite material as a whole. Composites researchers and manufacturers may seek to understand:

  • Mechanical properties of each constituent material
  • Distribution of constituent materials
  • Interfacial characteristics between matrix and reinforcement material
  • Behavior at elevated or reduced temperature
  • Dynamic mechanical properties

Bruker offers a suite of Hysitron nanomechanical test instruments to meet the mechanical testing needs for composites researchers and manufacturers. With our recently developed XPM (Accelerated Property Mapping) indentation technique, users can quickly obtain the mechanical properties of each material in their composites. Coupled with in-situ SPM Imaging, distribution of constituent materials can be easily measured. An electronic under-fill material was characterized using XPM. The results are shown in Figure 1.

Topography and Modulus of an Electronic Under-fill Material | Bruker

Figure 1. The topography and modulus of an electronic under-fill material consisting of glass beads embedded in a polymer matrix was mapped in a 10µm x 10µm area. 400 indents were performed in less than two minutes.

Bruker's Hysitron 2D transducer is a useful tool for studying material behavior at the interface of constituents in a composite. For example, a researcher was interested in observing the behavior of boron carbide particles in an aluminum matrix when scratched at a constant force. One of the results is shown in Figures 2 and 3.

Topographical SPM Images of Scratch Test on Composite Material | Bruker

Figure 2. The researcher was interested in studying the characteristics of a composite consisting of boron carbide particles in an aluminum alloy matrix. A Hysitron 2D transducer was used to scratch an exposed particle. The topographical SPM images are 20µm x 20µm (left) and 10µm x 10µm (right).

Lateral versus Normal Displacement from Scratch Test | Bruker

Figure 3. The topography over the exposed particle was traced before and after the scratch. The particle was unmoved by a 1mN constant load scratch.

Equipped with a nanoDMA III transducer, users can measure the dynamic mechanical properties of polymeric composites. Often this technique is most useful when coupled with the xSol High Temperature Stage so that the temperature dependent properties (such as storage or loss moduli) can be characterized. The glass transition temperature (Tg) can also be measured with a high degree of accuracy by performing a continuous DMA test while sweeping the temperature of the sample.

Tan(delta) Curves of an Electronic Under-fill Composite | Bruker

Figure 4. Tan(delta) curves of an electronic under-fill composite tested at 10Hz and 220Hz over a 40°C range.

Bruker's Hysitron TriboIndenter line is equipped with several tools needed to properly characterize a variety of composite samples. In-situ SPM imaging and property mapping are powerful tools used to understand the distribution and mechanical properties of individual components in a composite material. These, in combination with the xSol system and nanoDMA technique, make the Hysitron TriboIndenter an indispensable tool for composite researchers and manufacturers.