materials

• Material Testing is a test done to determine the properties of a substance in comparison with a standard or specification.
• The purpose of Material Testing is to determine quality of material, mechanical properties such as strength, hardness, ductility, toughness, etc, trace defects/ flaws in the materials, and evaluate materials potential in certain use.
• Material Testing involves mechanical properties such as strength, hardness, toughness, ductility, plasticity, brittleness, and elasticity.
• Strength is the ability of a material to withstand tensile force without fractured.
• Hardness is the measurement of a material's resistance to break, fracture or rupture.
• Toughness is the tendency of a material to fracture or fail upon the application of force, impact, or shock.
• Brittleness is the ability of a material to deformed permanently and will not return to its original shape after the load is removed.
• Plasticity is the quality of being pliable and flexible, like a piece of metal that can be bent into a thin wire.
• Ductility is the ability of a deformed material body to return to its original shape and size when the forces causing the deformation are removed.
• Elasticity is the ability of a material to recover its shape after deformation.
• Tensile testing is one of the most common mechanical testing techniques used to find out how strong a material is and also how much it can be stretched before it breaks.
• Tension testing is a destructive test process that provides information about the tensile strength, yield strength, and ductility of the metallic material.
• The three-point bending test is the most frequently studied bending load in materials testing, where a beam mounted on two supports is studied under a single force applied to the centre.
• A shear or torsion test is a mechanical test used to determine the material properties related to its shear strength or resistance to torsional deformation.
• Thermomechanical analysis involves the use of an apparatus that, through a probe transmitter and a transducer, can measure thermal expansion with respect to temperature differences.
• Interferometry is an optical imaging and interference system that measures the dimensional changes during heating or cooling in terms of monochromatic light wavelength density.
• If thermal expansion is not considered during construction and design, it could result in major structural damage in a machine or building.
• Dilatometry is a straightforward technique in which a test sample is placed in a furnace and heated to certain temperatures while the changes in the dimensions of the sample are captured via push rod sensors.
• Thermal expansion is a phenomenon that occurs when a material changes in length due to changes in temperature.
• Beam deflection refers to the bending or deformation of a structural beam under the influence of applied loads.
• The formula for thermal expansion is: ΔL = L0 x α x ΔT, where ΔL is the change in length, L0 is the original length, and α is the coefficient of linear expansion.
• Countless measures have been taken to prevent thermal expansion damage, and many ingenious technologies are developed relying on this phenomenon.
• Change in volume due to thermal expansion is calculated as: ΔV = V0 x β x ΔT, where ΔV is the change in volume, V0 is the original volume, and β is the coefficient of volume expansion.
• Compression tests are less significant for testing metallic materials compared to tensile tests, but are essential for studying building materials such as natural stone, brick, concrete, wood, etc.
• Compression testing machines are an essential tool for testing the compressive strength and other properties of materials to ensure the quality and reliability of products.
• The compression test is used to determine the elastic limit, proportional limit, yield point, yield strength, and compressive strength.
• The coefficient of thermal expansion (CTE) is a measure of how much a material expands or contracts with a change in temperature.
• The primary function of thermal expansion is to accommodate changes in temperature without causing damage to materials or structures.
• To determine the thermal expansion coefficient, two physical quantities (displacement and temperature) must be measured on a sample that is undergoing a thermal cycle.
• Chemical properties of a material include composition, corrosion resistance, crystal structure, microstructure, and stereospecificity.
• Physical properties of materials refer to their interaction with various forms of energy and with other forms of matter, including Curie point, density, dielectric strength, electrical resistivity, heat distortion temperature, melting point, Poisson’s ratio, refractive index, specified gravity, thermal conductivity, thermal expansion, and specified gravity.
• This type of cast iron contains nodular or spheroidal graphite, sometimes called nodular cast iron.
• Mottled iron contains both cementite and graphite and is between the gray and white irons in composition and performance.
• Ductile iron is similar to malleable iron in ductility is achieved by ladle additions.
• Malleable iron is a type of cast iron with its structure altered by thermal treatments to give it measurable ductility and increased tensile strength.
• This iron has a white appearance.
• Mechanical properties of materials are displayed when a force is applied to the materials, including comprehensive strength, creep, creep strength, endurance limit, flexural strength, hardness, modulus of elasticity, and comprehensive strength.
• Ferritic stainless steels contain chromium in the range of 16% to 20% and have carbon content less than 0.2%.
• Hot hardness refers to the ability of a steel to resist softening at high performance.
• Austenitic stainless steels have at least four major alloying elements, namely iron, chromium, carbon and nickel, with the chromium content ranging from 16% to 26%.