Composite Materials Characterization

The demand for innovative materials keeps increasing with the civilization development of the world. In a modern advanced society like ours, composite materials are actually in many aspects of our lives. Fiberglass, as the first modern composite, has been used in boat hulls, surfboards, sporting goods, swimming pool linings, building panels and car bodies. Carban fiber-based composites can offer lighter weight but stronger strength, which makes it popular among spacecraft, automobile, as well as competing sports goods. Many creative ceramic, polymer, carbon, metal composites and biomimetic materials are used as the matrix for some highly specialized purposes under Research and Development studies. Due to the excellent properties of composites, such as good dimensional stability, chemical stability and wide tolerance temperature, they have been widely applied in many areas.

Fig.1 Composite materials applied in transportation.

A composite material is normally made from two or more materials that can give superior properties compared to the individual constitutes. Without dissolving or blending each individual compound, the individual components can remain separate and distinct within the finished composite. Composite materials can offer modulus/vibration damping increases, tensile strength/ compression strength/interlaminar shear strength enhancement as well as improved fracture toughness.

The constituents of composites are mainly matrix, reinforcing material and coupling agent. The functions of each composite are different. For example, the functions of matrix are to form the homogeneous (continuous) phase, to bind reinforcement and to distribute load among fibers or particles; the function of reinforcing material is reinforcement.

The classification of composites can base on matrix material or geometry of reinforcement. When classifying is based on matrix, composites can be divided into three groups: polymer matrix composites (PMC), metallic matrix composites (MMC) and ceramic matrix composites (CMC). The geometry of reinforcement can be laminate, particle, and fiber. Therefore, the classification based on geometry of reinforcement is laminar composites, particulate composites and fibrous composites.

Fig. 2 The classification of composites based on matrix. Fig.3. The classification of composites based on geometry of reinforcement.

When obtaining a composite material, the properties of this material are critical. If a composite is expected to be used in some area, it needs to meet the mechanical and chemical requirements. Therefore, professional testing teams and methods are very important for determining the performances of a composite.

Mechanical properties of composites include tensile strength, compressive strength, bending strength, shear strength, hardness and fatigue. When testing these mechanical properties, testing environment is very important and standard testing environment must be guaranteed. Sample size and quantity must comply with standard test requirements^[1].

With professional knowledge of the various types of composites, as well as an understanding of the dependence of their behaviors on the characteristics/relative amounts/geometry/distribution, and properties of the constituent phases, scientists and engineers at Alfa Chemistry can provide many testing services about composite materials. Here are some examples.

• Universal testing machine is a desired candidate for composite material properties testing. Universal testing machine (UTM), also known as a universal tester, materials testing machine or materials test frame, is used to test the tensile strength and compressive strength of materials. The "universal" part of the name reflects that it can perform many standard tensile and compression tests on materials.

• X-Ray diffractometer is an instrument that can reveal information about the crystal structure, chemical composition, and physical properties of materials and thin films.

• Hardness tester is a method that can determine the hardness of a composite. The test method of hardness is various and the test principle is different. We can provide different hardness test methods that will meet your requirements, such as, Rockwell Hardness (HRA/HRB/HRC), Brinell Hardness (HB) and Vickers-hardness(HV).

• Scanning electron microscope (SEM) and transmission electron microscope (TEM) are very powerful instruments that can reveal the microscopic information of a composite, even in nanometer sizes regime. When SEM coupled with energy dispersive X-ray spectroscopy (SEM/EDX), elemental mapping of showing the spatial distribution of elements in a sample can be achieved.

Alfa Chemistry is professional in composite material characterizations with a fast turnaround time and can provide excellent customer services with accurate and reliable testing data. Welcome to contact us at any time for more information.

Reference

• A.Srivathsana, B.Vijayarama, R.Ramesha and Gokuldassb, Investigation On Mechanical Behavior Of Woven Fabric Glass/Kevlar Hybrid Composite Laminates Made Of Varying Fibre Inplane Orientation And Stacking Sequence, Materials Today: Proceedings, 2017,4(8), 8928-8937.