Glossary of Material Science

A metal or alloy that is heat-resistant, having a high melting point. Typical examples are tungsten, molybdenum, niobium, tantalum, and rhenium.

A hard, brittle, corrosion-resistant, gray to white metallic element extracted from wolframite, scheelite, and other minerals, having the highest melting point and lowest vapor pressure of any metal. Tungsten and its alloys are used in high-temperature structural materials; in electrical elements, notably lamp filaments; and in instruments requiring thermally compatible glass-to-metal seals. Atomic number 74; atomic weight 183.84; melting point 3,410°C; boiling point 5,900°C; specific gravity 19.3 (20°C); valence 2, 3, 4, 5, 6.

We produce a variety of tungsten heavy metal alloys based on the combinations: tungsten-nickel-iron, tungsten-nickel-cobalt and tungsten-nickel-copper. In all these materials, we take full advantage of tungsten's high density, its outstanding mechanical damping capabilities and its great ability to absorb X-ray and gamma radiation.

Tungsten composites add the more subtle properties of softer metals to the brute strength of tungsten for greater machinability. Copper tungsten allows you to benefit from both the thermal advantage of copper and the very low expansion of tungsten.

Powder metallurgy is the process of blending fine powdered materials, pressing them into a desired shape or form (compacting), and then heating the compressed material in a controlled atmosphere to bond the material (sintering). The powder metallurgy process generally consists of four basic steps: powder manufacture, powder blending, compacting, and sintering. Compacting is generally performed at room temperature, and the elevated-temperature process of sintering is usually conducted at atmospheric pressure. Optional secondary processing often follows to obtain special properties or enhanced precision.

Filling the pores of a metal powder compact with metal having a lower melting point.Movement of molten metal into the pores of a fiber or foam metal.

sintering, process of forming objects from a metal powder by heating the powder at a temperature below its melting point. In the production of small metal objects it is often not practical to cast them. Through chemical or mechanical procedures a fine powder of the metal can be produced. When the powder is compacted into the desired shape and heated, i.e., sintered, for up to three hours, the particles composing the powder join together to form a single solid object.

In technology, the main method of forming molten metals, glass, or other substances into shapes that are small in cross-section in comparison with their length, such as bars, sheets, rods, rails, and girders. Rolling is the most widely used method of shaping metals and is particularly important in the manufacture of steel. The process consists of passing the metal between pairs of rollers revolving at the same speed but in opposite directions and spaced so that the distance between them is slightly less than the thickness of the metal.

The part of a heating appliance in which electrical energy is transformed into heat.

Legislation and regulations to protect the public and laboratory or industrial workers against radiation. Measures to reduce exposure to radiation.

A device which counterbalances the original load in elevators and skip and mine hoists, going up when the load goes down, so that the engine must only drive against the unbalanced load and overcome friction. Any weight placed on a mechanism which is out of balance so as to maintain static equilibrium.

A device for boring holes; it is in the form of a cylindrical spindle with radially placed holes, either rectangular or round, in which individual or block cutters are fastened. Boring bars usually have a shaft that is fastened to the spindle of a boring machine.

The aggregate of the irregularities that form the microrelief of a part's surface. Surface roughness results mainly from plastic deformation of the surface layer of a work-piece during machining. It is caused by, for example, irregularities of a tool's cutting edges, friction, the tearing of particles of material from the surface of the workpiece, and vibration of the workpiece or the tool.

A powder, liquid, or semiliquid used to give smoothness, surface protection, or decoration to finishes; for example, finely ground red oxide (rouge) is used to polish plate glass, mirror backs, and optical glass; solvent-wax liquids and pastes are used to protect and enhance leather and wood surfaces; nitrocellulose lacquers are used to paint finger- and toenails.

A process by which materials that conduct electricity can be removed from a metal by an electric spark; used to form holes of varied shapes in materials of poor machinability. Abbreviated EDM. Also known as electrical discharge machining; electric spark machining; electroerosive machining; electrospark machining.

Welding in which an arc plasma from a nonconsumable tungsten electrode radiates heat onto the work surface, to create a weld puddle in a protective atmosphere provided by a flow of inert shielding gas; heat must then travel by conduction from this puddle to melt the desired depth of weld. Abbreviated TIG welding.

A metallic alloy is a mixture of a metal with other metals or non-metals. Ceramics can also be mixed to form alloys. Binary alloys are alloys of two elements only.

A measure of the ability of a material to conduct an electric current or impulse. It is defined as the reciprocal of the resistivity of the material, and is expressed in siemens m-1.

A chart of the chemical elements that displays them in rows horizontally in order of increasing atomic number and vertically according to similarity of the chemical properties of their atoms. The position of an element on the table thus gives useful information about the structure and chemical properties of the element.

A condition under which induction of a ferromagnetic material has reach its maximum value with the increase of applied magnetizing force. All elementary magnetic moments have become oriented in one direction at the saturation status.

Weight percentage signifies weight percentage, so Cu/Al 73/27 wt% would have 27% of the weight of the alloy as Aluminium and 73% of the weight of the alloy as Copper.