## Materials

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.

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## Materials Glossary

### A

• 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.

### B

• 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.

### C

• 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 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.

### D

• Ductility  -  That property of metal which allows the metal to be permanently deformed before final rupture.

### E

• 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.

### F

• 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.
• Free Machining  -  That property of steel imparted by additions of sulfur, selenium or phosphorous which promote chip breakage and permit increased machining speeds.

### G

• Galling  -  The damaging of one or both metallic surfaces by removal of particles from localized areas during sliding friction.
• Grains  -  Individual crystals in metal.

### H

• 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.

### I

• Impact Test  -  A test designed to determine the energy absorbed in fracturing a test bar.

### K

• 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.

### L

• 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.

### M

• 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.

### N

• 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.

### O

• 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.

### P

• Pickling  -  Immersion in dilute acid or other suitable media for the removal of oxide scale from hot-rolled or otherwise sealed surfaces.
• 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.

### Q

• 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.

### R

• 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.
• 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.

### S

• 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.

### T

• 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 Expansion Coefficient  -  The percentage change in the length of the material per degree of temperature change, heated solid or liquid.

### V

• 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.

### W

• Water Quench  -  Cooling steel from its quenching temperature with water.

### Z

Display #
Title
Alloy
Vickers Hardness Test

Tags: Glossaries