A

ABRASION RESISTANCE: The ability of a fiber or fabric to withstand surface wear and rubbing.

AFTERGLOW: The flameless, glowing combustion of certain solid materials that occurs after the removal of an external source of ignition or after the cessation of combustion of the material.

ALKALINE: A term used to describe a material having a pH greater than 7.0 in water.

ASH: To drive off all combustible or volatile substances.

ASH CONTENT: The nonvolatile inorganic matter of a compound which remains after subjecting it to a high decomposition temperature.

ABSORBENCY: The ability of a fabric to take in moisture. Absorbency is a very important property, which effects many other characteristics such as shrinkage, stain removal, water repellency, and wrinkle recovery

Acid Dyes: A class of dyes used on wool, other animal fibers, and some manufactured fibers. Acid dyes are seldom used on cotton or linen since this process requires a mordant. Acid dyes are widely used on nylon when high washfastness is required. In some cases, even higher washfastness can be obtained by aftertreatment with fixatives.

Aniline Dyes: Dyes derived chemically from aniline or other coal tar derivatives.

Anthraquinone Dyes: Dyes that have anthraquinone as their base and the carbonyl group (>C=O) as the chromophore. Anthraquinone-based dyes are found in most of the synthetic dye classes.

Azo Dyes: Dyes characterized by the presence of an azo group (-N=N-) as the chromophore. Azo dyes are found in many of the synthetic dye classes.

Air Content
This test method covers the determination of the air content in freshly mixed concrete. The test determines the air content in freshly mixed concrete exclusive of any air that may exist inside voids within aggregate particles.

Asbestos
A large number of countries have introduced legislation concerned with the use of asbestos due to the considerable risks associated with handling or processing the material. Handling asbestos in a responsible manner demands a high degree of expertise. SPECTRO can do air particle measurements, identification of asbestos and Man Made Mineral Fibres (MMMF) in materials and air.

AIR HARDENING STEEL -An alloy steel which does not require quenching from a high temperature to harden but which is hardened by simply cooling in air from above its critical temperature range.

ANNEALING - Applies normally to softening by changing the microstructure and is a term used to describe the heating and cooling cycle of metals in the solid state. The term annealing usually implies relatively slow cooling in carbon and alloy steels. The more important purposes for which steel is annealed are as follows: To remove stresses; to induce softness; to alter ductility, toughness, or electric, magnetic or other physical and mechanical properties; to change the crystalline structure; and to produce a definite microstructure.

AUSTEMPERING - This is a method of hardening steel by quenching from the austenitizing temperature into a heat extracting medium (usually salt) which is maintained at some constant temperature level between 400” and 800” and holding the steel in this medium until austenite is transformed to bainite. The austempering process is limited to sections less than `/2” diameter. The advantages of this method of interrupted quenching are increased ductility and toughness at the resulting hardness of RC 45-55.

AUSTENITE - The solid solution of iron and carbon which is attained by heating to high temperatures above the upper critical temperature. This temperature or temperature range is called the austenitizing temperature and must be attained to obtain the proper microstructure and full hardness of steel in heat treating. The austenitizing temperature varies for the different grades of carbon, alloy and tool steels.

Austempering: Quenching from a temperature above the transformation range, in a medium having a rate of heat abstraction high enough to prevent the formation of high temperature transformation products, and then holding the alloy, until transformation is complete, at a temperature below that of pearlite formation and above that of martensite formation.

Austenitizing: Forming austenite by heating into the transformation range (partial austenitizing) or above the transformation range (complete austenitizing). When used without qualification, the term implies complete austenitizing.

Aluminum is widely used as a deoxidizer. Aluminum can control austenite grain growth in reheated steels and is therefore added to control grain size. Aluminum is the most effective alloy in controlling grain growth prior to quenching. Titanium, zirconium, and vanadium are also valuable grain growth inhibitors, but there carbides are difficult to dissolve into solution in austenite.

Austenitic stainless steels have a austenitic, face centered cubic (fcc) crystal structure. Austenite is formed through the generous use of austenitizing elements such as nickel, manganese, and nitrogen. Austenitic stainless steels are effectively nonmagnetic in the annealed condition and can be hardened only by cold working. Some ferromagnetism may be noticed due to cold working or welding. They typically have reasonable cryogenic and high temperature strength properties. Chromium content typically is in the range of 16 to 26%; nickel content is commonly less than 35%.

Alpha alloys commonly have creep resistance superior to beta alloys. Alpha alloys are suitable for somewhat elevated temperature applications. They are also sometimes used for cryogenic applications. Alpha alloys have adequate strength, toughness, and weldability for various applications, but are not as readily forged as many beta alloys. Alpha alloys cannot be strengthened by heat treatment.

Alpha + beta alloys have chemical compositions that result in a mixture of alpha and beta phases. The beta phase is normally in the range of 10 to 50% at room temperature. Alloys with beta contents less than 20% are weldable. The most commonly used titanium alloy is Ti-6Al-4V, an alpha + beta alloy. While Ti-6Al-4V is fairly difficult to form other alpha + beta alloys normally have better formability.

B

BURSTING STRENGTH: 1. The ability of a material to resist rupture by pressure. 2. The force required to rupture a fabric by distending it with a force applied at right angles to the plane of the fabric under specified condition. Bursting strength is a measure widely used for knit fabrics, nonwoven fabrics, and felts where the constructions do not lend themselves to tensile tests.

BLEND: - A term applied to a yarn or a fabric that is made up of more than one fiber. In blended yarns, two or more different types of staple fibers are twisted or spun together to form the yarn. Examples of a typical blended yarn or fabric is polyester/cotton.

BLACK STANDARD THERMOMETER - A temperature measuring device, the sensing unit of which is coated with a black material designed to absorb most of the radiant energy encountered in lightfastness testing and is thermally insulated by means of a plastic plate.

BAINITE - A decomposition or transformation product of austenite which is a type of microconstituent or structure in steel. This term is used by metallurgists to describe a particular structure of steel when the steel is polished, etched and examined with a microscope.
BRINELL HARDNESS - A hardness number determined by applying a 3000 kilogram load to the surface of the material to be tested through a hardened steel ball of 10mm. The diameter of the depression is measured and the hardness is the ratio of load to spherical area of the impression. Tables of numbers have been prepared, and the hardness is read from the table from the diameter of the depression.

Brinell Hardness Testing - In this test a standard constant load, usually 500 to 3,000 kg, is applied to a smooth flat metal surface by a hardened steel-ball type indenter, 10 mm in diameter. The 500-kg load is usually used for testing nonferrous metals such as copper and aluminum alloys, whereas the 3,000-kg load is most often used for testing harder metals such as steels and cast irons. The numerical value of Brinell Hardness (HB), is equal to the load, divided by the surface area of the resulting spherical impression.


Boron is added to fully killed steel to improve hardenability. Boron-treated steels are produced to a range of 0.0005 to 0.003%. Whenever boron is substituted in part for other alloys, it should be done only with hardenability in mind because the lowered alloy content may be harmful for some applications.
Boron is a potent alloying element in steel. A very small amount of boron (about 0.001%) has a strong effect on hardenability. Boron steels are generally produced within a range of 0.0005 to 0.003%. Boron is most effective in lower carbon steels.

Bluing: A treatment of the surface of iron-base alloys, usually in the form of sheet or strip, on which, by the action of air or steam at a suitable temperature, a thin blue oxide film is formed on the initially scale-free surface, as a means of improving appearance and resistance to corrosion. This term is also used to denote a heat treatment of springs after fabrication, to reduce the internal stress created by coiling and forming.

Beta alloys have good forging capability. Beta alloy sheet is cold formable when in the solution treated condition. Beta alloys are prone to a ductile to brittle transition temperature. Beta alloys can be strengthened by heat treatment. Typically beta alloys are solutioned followed by aging to form finely dispersed particles in a beta phase matrix.