Using SEM to Design and Analyze Novel Composites

The technical specifications of next-generation materials are taking Phenom-World’s technology to a whole new level, enabling it to manufacture products with exceptional properties that were not possible to accomplish in the past.

These materials are the outcomes of a large drive toward innovation in material science and could only be achieved because of the discovery of the first composite materials and their introduction into the industrial landscape.

This article describes the development process of these next-generation materials— and equally essential: how their chemical composition is examined, and their performance is determined.

How Beneficial Properties of Composite Materials are Created and Preserved

Some materials have exceptional properties that provide the ideal fit with a specific application. At times, it is unfortunate that, the environment affects these materials to such an extent that they cannot be easily used. They also need constant replacement and fixing, thus compromising all the benefits that come from their use.

By creating multiple layers, or using a coating, such fragile materials can be protected and used, with all the advantages that they bring.

Figure 1. Glass sheet coated with different materials. The multiple layers add specific properties to the product.

For instance, introducing nanofibers in a slab can significantly enhance its resistance to torsion, flexion or traction. These materials generally have a matrix (the external part of the material, directly exposed to the stress) that is supported by a network of fibers. When the material is subjected to stress, the stress is transferred to the fibers. The fibers can handle the applied force effortlessly, responding with an elastic deformation. Once the stress is removed, the fibers will bring back the material to its original state.

This stress-transfer process is what led to the manufacture of self-healing materials. A typical instance is the plastic covers of certain smart phones which, when scratched, can recover from the condition in a few minutes. If the scratch is not very deep, it will totally disappear and the ‘brand-new’ feeling of the phone will stay longer.

The crafting of these materials demands high-level engineering and is the consequence of a big investment in research. To be specific, Scientists have focused their attention on how to transfer the stress from the matrix to the fiber, without having the latter slipping within the structure. A number of different solutions were considered and studied, such as producing a complicated fibrous skeleton or coating the fibers with a material that enhances the shear stress transmission at the fiber-matrix interface.

Figure 2 & 3. Different kinds of fiber weaving offer different resistance to stress. The appropriate weaving technique is chosen according to the application.

How Next-Generation Composite Materials are Analyzed and Measured

As these investigations were carried out on nano-scaled materials, electron microscopes were used for the measurements and analysis. In fact, a desktop scanning electron microscopy (SEM) evaluates the diameter of the fibers and monitors how they change along the structure. At the same time, the quality and chemical composition of the coating can also be analyzed in order to substantiate that the adhesion of the fiber to the matrix is optimized. An energy dispersive X-ray analysis (EDS) can be used to do this process.

By the way, composite materials are not a recent invention. The ancient population inhabiting the European continent was already mixing different types of materials for practical or decorative purposes. The discovery of archaeological grave goods in the royal and imperial tombs in the Speyer Cathedral in Speyer, Germany, is an example which showed that textile fibers were mixed with golden threads.

Electron microscopy has been productively used to carry out several analyzes of the tombs’ contents within the KUR-Project “Conservation and restoration of mobile cultural assets” in Germany.

This information has been sourced, reviewed and adapted from materials provided by Phenom-World BV.

For more information on this source, please visit Phenom-World BV.