All materials are made up of atoms of various elements from periodic table. More often materials are made up of more than one type of atoms. Materials are generally classified in to organic and inorganic materials. Some simple examples of organic materials are plastics, polymers, bio polymers, coal, crude oil, etc. Common examples of inorganic materials are metals, alloys, ceramics, glass, concrete, etc. They are also classified as amorphous, crystalline materials based on the fundamental arrangement of atoms that make up the materials.
Material characterization involves a broad group of analytical procedures used to evaluate chemical and physical make up of any materials. It is different from material testing in that it focusses on fundamental characteristics rather than applied or utility properties. Simple example is chemical analysis of materials to identify the chemical elements or molecules involved in the constitution of a material. Physical characterization involves measuring physical properties and microstructure, etc.
At Touchstone Testing Laboratory, we offer the following services.
Physical properties of materials encompass a wide range of properties that can be classified in to volumetric properties, thermal properties, electrical properties, etc. Major volumetric properties are specific gravity, density, viscosity, surface tension, etc. Included in the thermal properties are thermal conductivity, thermal expansion, phase change temperatures, etc., while electrical properties include mainly bulk and surface electrical conductivity. These properties along with mechanical and chemical properties are needed for selection, design and manufacturing of products and components.
Capability – At touchstone testing laboratory we have equipment and capability to measure the following physical properties
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Fundamental building blocks of materials are atoms. In solids and to some extant in liquids, atoms are generally arranged in to what are called crystals in a repetitive manner. A simple example is the common salt, sodium chloride, where sodium and chlorine atoms are arranged alternatively at the corners of a simple cube. The distance between the sodium and chlorine atoms is determined by the interatomic attractive and repulsive forces. Several different types of crystalline motifs are available for materials depending on the type of atoms involved. Basic crystal motifs are cubic, hexagonal, tetragonal, orthorhombic, monoclinic and triclinic forms. Further materials will contain what are called grains with each grain containing repetitive patterns of atoms in one of the above crystalline motif. Thus, materials are also called poly crystalline materials. Most engineering materials in addition will also have additional matter, also called second phase, like impurities in the form of inclusions, etc. Often these second phases may also contribute to the property of the material. Thus, materials are in general poly crystalline poly phase. Microstructural characterization involves identifying, measuring size and shapes of these grains and phases.
Capability – At Touchstone testing laboratory we routinely carry out microstructural characterization of metallic, polymeric, ceramic materials and composites for aerospace, automotive, power generation OEMs as well as material and composite manufacturers. We have analyzed microstructures of variety of ferrous products like carbon steel, stainless steel, interstitial free steels, regular and alloy cast irons, etc. We have also extensive experience in analyzing nonferrous materials like aluminum, aluminum alloys, copper, brass, bronze, and exotic materials nickel, chromium, niobium, tungsten-based alloy systems and PGM materials. We can analyze also fiber materials like carbon, glass, ceramic as well as metal fibers and natural fibers. We have capability to analyze dust particles like soot, silica, etc., and powder metals. Following facilities are available for materials characterizations.
Some relevant standards:
Fundamental building blocks of observable materials are atoms and molecules. Properties of materials depend on how these atoms and molecules combine and interact with each other. Chemical analysis is a way to understand the constitution of materials in terms of atoms and combinations of them.
Many different techniques are available to analyze the chemistry of materials. These are generally classified in to wet and dry chemical analysis. Wet method involves basically dissolving the materials in acids or alkali solutions and titrating the solutions against standards. Alternative is to use dry methods where the materials are irradiated using high energy radiations like X rays, g rays, lasers, etc., as well as particle beams like electrons, neutrons, etc., and the response is analyzed through techniques like spectroscopy.
Capability – At Touchstone testing laboratory, we have limited capability to analyze samples chemically. We use electron beams in an electron microscope to generate x rays which are then analyzed for the content semi quantitively. We also have inductively coupled plasma unit to analyze chemistry of metallic samples like aluminum alloys.
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