Material, abbreviated as MATL, is the matter an object is made of. There are four categories of material: ceramic, composite, metal and polymer.
- Ceramic - inorganic non-metallic solid comprised of either metal or non-metal compounds made by heating together these materials.
- Composite - material mixture of two or more materials with different properties combined to produce a new material.
- Metal - chemical elements that are good conductors of heat and electricity.
- Polymer - a long chain of molecules linked together.
Nomenclature & Symbols
- List of all Site Glossaries
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- Aging - The term origionally applied to the process or sometimes to the effect of allowing a metal to remain at ordinary temperatures.
- Air Hardening - A hardening process wherein the steel is heated to the hardening temperature and cooled in the air.
- Alclad - The common name for a type of clad wrought aluminum product with coatings of high purity aluminum or an aluminum alloy different from the core alloy in composition.
- Alloy - A metallic substance consisting of two or more elements, of which at least one is a metal, and in which all elements are miscible in the molten state, and which do not separate when solid.
- Alloying Elements - Chemical elements constituting an alloy. In steel, usually the elements added to modify the properties of the steel.
- Annealing - A heating and controlled cooling operation to impart specific desirable properties generally concerned with subsequent fabrication of the alloy.
- Austenite - A solid solutionin which gamma iron is solvent, having a face-centered cubic crystal structure.
- Austenite Steel - Steel, which due to its composition has a stable structure at normal (room) temperature.
- Bent Test - A test commonly used to determine relative ductility of a sample by bending it over a given radius through a given angle.
- Brass - A copper-base alloy in which zinc is the principle added element.
- Brinell Hardness Number - A value assigned to the hardness of metals and alloys. To do this a steel ball is pressed into the surface of an object by a known load to deform the material.
- Capacitance - The ability to hold an electric charge.
- Capacitor - Behaves as a charge storage device. Holds an electric charge when voltage is applied across it and gives up the stored charge when required.
- Carbon Steel - A metal alloy, a combination of two elements, iron and carbon, where other elements are present in quantities too small to affect the properties.
- Carburizing - Diffusing carbon into the surface of iron-base alloys by heating in the presence of carbonaceous materials.
- Case Hardening - Carburizing, nitriding, or cyaniding and subsequent hardning by suitable heat treatment.
- Casting - Pouring molten metal into a mold or a metal object.
- Cementita - An iron-carbon compound with the chemical formula \(Fe_3C\) often called iron carbide.
- Chemical Analysis - Seperating an alloy into its component elements and identifying them.
- Chromium - A hard crystaline metal used as an alloying element to give resistance to heat, corrosion, and wear and increase strength and hardenability.
- Cleanroom - A room/facility in which the air supply, air distribution, filtration of air supply, materials of construction, and operating procedures are regulated to control airborne particle concentrations to meet approperate cleanliness levels.
- Cold Working - Permanent deformation of a metal below its recrystallization temperature.
- Composite Material - A combination of two materials with different chemical and physical properties.
- Compressive Strength - The ability to withstand compressive stresses.
- Compressive Stress - Stress caused by a compressive load or in fibers compressed by a bending.
- Conductor - A material through which heat passes and allows the free flow of electric charge.
- Cooling Stress - Stress caused by uneven contraction, external restraint or localized plastic deformation during cooling.
- Corrosion - The thinning of a pipe wall that is typically caused by a chemical reaction from a corroding fluid or agent and is limited almost exclusively to metal products.
- Creep - Plastic flow of metal, usually occuping at high temperatures, subject to stress appreciably less than its yield strength.
- Crucible - A container that can withstand very high temperatures and is used for metal, glass, and pigment products.
- Cyaniding - A process of case hardening a ferrous alloy by heating in a molten cyanide salt bath, thus causing the alloy to absorb carbon and nitrogen simultaneously.
- Ductility - That property of metal which allows the metal to be permanently deformed before final rupture.
- Elasticity - Measures the stiffness of an elastic material. Elasticity can deformed body and return to its original shape when the forces exerted are removed.
- Elastic Limits - Maximum stress that can be applied to a metal without causing plastic deformation that will remain after the load is relaxed to zero.
- Electrode - An electrical conductor used to contact a nonmetallic part of a circuit.
- Electron - A subatomic particle found in all atoms, electrons carry electricity by flowing from one atom to the next in a conductive material.
- Elongation - The increase in length to which a material is to be stretched prior to rupture.
- Endurance Limit - A limit of stress below which metal will withstand fracture.
- Eutectoid Steel - A carbon steel containing 0.80% carbon becomes a soild solution at any temperature in the austenite temperature range between 1333 F and 2500 F.
- Fatigue - The tendency of a metal to fracture under conditions of repeated cyclic stressing below the ultimate tensile strength but above the yield strength.
- Ferrite - A solid solution in which alpha iron is the solvent and having a body-centered cubic crystal structure.
- Ferrite Steel - Steel which, due to its composition, is not hardenable by heat treatment.
- Ferrous Metal - Mostly contain iron.
- Free Machining - That property of steel imparted by additions of sulfur, selenium or phosphorous which promote chip breakage and permit increased machining speeds.
- Galling - The damaging of one or both metallic surfaces by removal of particles from localized areas during sliding friction.
- Grains - Individual crystals in metal.
- Hardenability - In a ferrous alloy, the property that determines the depth and distribution of hardness induced by heat treating and quenching.
- Hardening Precipitation - Hardening of metallic alloys, by aging, which results from the precipitation of a constituent from a super-saturated solid solution usually non-ferrous alloys.
- Hardness - The property of a material that enables it to resist plastic deformation, usually by penetration. However, the term hardness may also refer to resistance to bending, scratching, abrasion or cutting.
- Heat Treatment - The heating and cooling of metals or alloys.
- Homogenizing - A process of heat treatment at high temperature to eliminate or decrease chemical segregation by diffusion.
- Hooke's Law - Stress is proportional to stress in the elastic region.
- Hot Forming - Working operations performed on metals heated to temperatures above room temperature.
- Hot Rolled - A metal forming process in which metal stock is passed through a pair of rollers.
- Hot Working - Hot forming above the recrystallization temperature.
- Hydrogen Embrittlement - A brittleness sometimes engendered by contact with plating and pickling solution acid due to absorption of hydrogen by the metal.
- Hypereutectoid Steels - Steel containing from 0.80% to above 2.0% carbon.
- Hypoeutectoid Steels - Steel containing less than 0.80% carbon.
- Impact Test - A test designed to determine the energy absorbed in fracturing a test bar.
- Kerf Loss - The amount of material loss during a cutting process.
- Killed Steel - Steel in which sufficient deoxidizing agents have been added to prevent gas evolution during solidification.
- Levitation - Separation of fine powder from coarse material by forming a suspension of the fine material in a liquid.
- Levitation Melting - An induction melting process in which the metal being melted is suspended by the electromagnetic field and is not in contact with a container.
- Magnetic Particle Testing - A method of inspection consists in suitable magnetizing the material and applying a prepared magnetic powder which adheres along lines of flux leakage.
- Martensite - An unstable constituent in quenching steel, the hardest of the transformation products of austenite.
- Martensitic Steel - Steel which, due to its composition, has martensite as its chief constituent after cooling. The hardenable stainless types are all martensite steels.
- Mask - A patterned layer of material used to prevent the etching of the material directly beneath it.
- Mechanical Properties - Those properties that reveal the reaction, elastic or plastic, of a material to an applied stress, or that involved the relationship between stress and strain.
- Normalizing - A process in which a steel is heated to a suitable temperature above the transformation range and is subsequently cooled in still air at room temperature.
- Oil Quench - A quench from the hardening temperature, in which oil is the cooling medium.
- Olsen Test - This is a cupping test made on an Olsen machine as an aid in determining ductiity and deep drawing properties.
- Overheating - Heating to such a temperature that while the properties of the metal are impared, it has not been burned and can therefore be restored by heat treatment.
- Physical Properties - Those properties familiarly discussed in physics, for example, density, electrical conductivity, and thermal expansion coefficient, exclusive of those described under mechanical properties.
- Pickling - Immersion in dilute acid or other suitable media for the removal of oxide scale from hot-rolled or otherwise sealed surfaces.
- Pitting Resistance Equivalent Number (PREN) - PERN is a way to measure the pitting corrosion resistance of various types of stainless steel in a chlorine based environment.
- Plasticity - The ability of a metal to be deformed extensively without rupture.
- Plating - Deposition of a thin film of a metal or alloy on a different base metal from a solution containing ions of the plating metal.
- Plating Rack - A fixture used to hold work and conduct current to it during electroplating.
- Poisson's Ratio - The elastic ratio between lateral strain and longitudinal strain.
- Quenching - The fast cooling of metals or alloys for the process of hardening. This process can be done with air, oil, or water. If the metal cools too quickly due to a large flow of heat into the thick base plate, the weld may become brittle, having low fracture toughness.
- Quenching Medium - The m,edium used for cooling steel during heat treatment, usally air, oil, salt, or water.
- Quenching Temperature - The temperature from which steel is quenched during a heat treating process.
- Radiography - The use of X-rads or gamma radiation to detect internal structural defects in metal objects.
- Refractory Metals - Metals such as tungsten, columbium, tantalum, molybdenum, which have relative high melting temperatures.
- Resilience Modulus - The amount of energy a material can absorb and still return to its origional shape.
- Rockwell Hardness Test - Forcing a cone-shaped diamond or hardened steel ball into the specimen being tested under standard pressure. The depth of penetration is an indication of the Rockwell Hardness.
Shear Modulus - The ratio of the tangential force per unit area applied to a body or substance to the resulting tangential strain within the elastic limits.
- Shear Stress - Tends to deform the material by breaking rather than stretching without changing the volume by restraining the object.
- Stiffness - The resistance of the elastic deformation of an object that applies to both compression and tension.
- Superconductivity - A phenomenon of exactly zero electrical resistance and expulsion of magnetic fields occuring in certain materials when cooled below a characteristic critical temperature.
- Temper - The amount of hardness that an alloy has after cold working or heat treatment.
- Temper Brittleness - Brittleness that results when certain steels are held within or slowly cooled through a certain range of temperature below the transformation range.
- Tensile Strength - The maximum stress a material can resist before it starts to elongate.
- Thermal Conductivity - The ability to transfer heat within a material without any motion of the material.
- Thermal Expansion Coefficient - The percentage change in the length of the material per degree of temperature change, heated solid or liquid.
- Vacuum Hot Pressing - A method of processing materials, especially metal and ceramic powders, at elevated temperatures, consolidation pressures, and low atmospheric pressures.
- Vacuum Melting - A process by which alloys are melted in a near-perfect vacuum to prevent contamination by atmospheric elements.
- Vickers Hardness Test - An indentation hardening test utilizing a diamond pyramid and useful over the entire range of common metals.
- Water Quench - Cooling steel from its quenching temperature with water.
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