Material Science: Structure, Families, and Properties Explained
Material Structure and Composition
Structure of Materials: The structure of a material depends mainly on the arrangement of atoms, ions, or molecules that constitute a solid element and the binding forces between them. This arrangement allows for a three-dimensional object to be formed. Materials with a crystalline structure are called solid or crystalline materials, such as some metals and ceramics.
Material Families and Their Characteristics
Families: Materials are characterized and grouped into families based on their characteristics and the role of their components. These families include metals, ceramics, polymers, and electronic materials. The similarity of their specific physical properties is the gold standard for differentiation, defining families that exhibit distinct mechanical properties, electrical conductivity, magnetic properties, thermal properties, nuclear properties, corrosion resistance, and optical properties.
Nature of Material Components
Nature of Components:
a) Metals
Inorganic compounds, mainly metal oxides or metal salts. Their characteristics form a crystalline structure with specific interatomic bonds. They generally have medium temperature resistance, are good conductors of electricity and heat, are tough and deformable, and possess high densities. Examples include steel, aluminum, copper, iron, and titanium.
b) Ceramics
Inorganic compounds composed of oxides and metal salts, excluding pure metals and precious metals. They have an ionic bond, forming a specific crystalline structure. Ceramics are poor conductors of heat, fragile, and not easily deformable, but they have high strength at high temperatures and average densities. Examples include brick, tile, porcelain, and glass.
c) Polymers
Organic compounds made up of very long linear chains or networks based on carbon, hydrogen, oxygen, or other non-metals. They have covalent bonds, are resistant to low temperatures, are poor conductors of electricity and heat, and have low densities (e.g., polyethylene, nylon, polyester). Some are fragile, while others are tenacious plastics.
d) Electronic Materials
Inorganic compounds based on silicon and germanium. They have a covalent bond and consist of a metal-type crystal structure. They are semiconductors, and their conductivity is conditioned, as seen in diodes, chips, and thyristors.
e) Composite Materials
Materials composed of one or more materials, which tend mainly to improve conditions and material properties. This involves enhancing the weak properties of one material with the strength of another, potentially changing its structure. An example is reinforced concrete, where a metal chain (reinforcement) within the concrete matrix provides greater tensile strength, acting as a stitch.
Material Families and Properties
Materials are used to store or transmit variables that define different energies, such as mechanical, electrical, magnetic, chemical, thermal, and wave energies. For example, mechanical energy is defined by the variables of force and displacement, and its requirements involve physical or chemical properties. These properties make up the index of analysis, classifying them as components of each type of energy.
Key Material Properties
Mechanical properties: Materials must be capable of transmitting mechanical energy and supporting required movements. This involves supporting static and dynamic stresses, which are identified in mechanical applications. These properties are formed by plastic deformation techniques, allowing shallow landslides, working in a field of low, medium, and high temperatures.
Thermal Properties
Thermal: Thermal properties involve two types of functions: thermal energy storage and subsequent transmission. This is defined by the interaction of thermal capacity and mass temperature. The transfer of thermal energy occurs through the interaction of the transmission coefficient (k), which characterizes the material and temperature.
Electrical Properties
Electricity: Electric currents interact with the electric field and potential difference. The layers of each material allow the passage of electric field strengths, which vary depending on the application. This is explained by the inverse relationship between current and voltage, which is determined by the permissiveness of the material.