ALUMINUM GLOSSARY - Q, R

Quench, Air and Water

Usually refers to quenching or rapid cooling at the die, where large volumes of forced air, water or a combination thereof are directed against aluminum extruded sections as they emerge from the die.

Quenching

Controlled rapid cooling of a metal from an elevated temperature by contact with a liquid, a gas, or a solid.

Radial Layout

The method of locating the apertures in a die so that the major axis of each profile lies along a circle of defined radius, giving each portion of bearing surface the same relationship to the center of the die as similar portions on other profiles.

Ram

The press component which applies force against the dummy block. Ram and stem are interchangeable terms describing any extension of the main cylinder in an extrusion press.

Reciprocator

A mechanical device which moves an applicator along a determined path repeatedly.

Recovery

The amount of saleable aluminum in the form of extrusions obtained from a press run. The recovery ratio is the proportion of such saleable metal to either the original ingot or to the ready-to-extrude billet, as the case may be.

Reduction

In metallurgy, the electrochemical process by which purified alumina (aluminum oxide) is broken down into its constituents, freeing metallic aluminum.

Reduction Ratio (Extrusion Ratio)

The comparison of the cross-sectional billet area to total cross-sectional area of the resulting extrusions. This is determined by the cross-sectional area of the container or upset billet divided by the cross-sectional area of the combined die openings.

Refined Aluminum

Aluminum of very high purity (99.950 percent or higher) obtained by special metallurgical treatments.

Reflectivity

The ability of a surface to reflect light and other electromagnetic radiation. Aluminum has high reflectivity: 80% or more for visible light, and 90% or more for infrared radiation.

Reheating

Heating metal again to hot-working temperature. In general no structural changes are intended.

Relieved

Aperture or opening in a die where its entrance is smaller than the exit.

Residual Stresses

Those stresses set up within a metal as the result of non-uniform plastic deformation which may be caused by drastic temperature gradients in quenching.

Resilience

The ability of a material to regain its original shape after distortion. Aluminum is a resilient material.

Resolution (of a measuring instrument)

The smallest unit of measure that an instrument is capable of accurately and repeatedly indicating.

Restrictor Bumps (dams, speed bumps)

A bulge or hump in the die's metal flow area serving as a means of controlling the flow or feed of metal.

Rib

An elongated projection on a shape, forging or casting to provide stiffening.

Ring Tooling (die ring)

A cylindrical sleeve that holds the die and backer in axial relationship to each other.

Rivet

(1) To connect two or more pieces of material by inserting in a hole through them a metal pin with a head on one end of it, and then forming a second head on the other end; (2) The connecting pin itself.

Rockwell Hardness

See Hardness, Rockwell .

Rod

A solid wrought product, long in relation to its cross-section, which is not less than 0.375 inch in diameter. (Smaller sizes are classified as wire.)

Rod, Alclad

Rod having on its surface a metallurgically bonded aluminum or aluminum alloy coating that is anodic to the core alloy to which it is bonded, thus electrolytically protecting the core alloy against corrosion.

Rod, Extruded

Rod produced by hot extruding.

Rod, Rolled

Rod produced by hot rolling.

Rod Runout Length

The length of extrusion rod from each billet.

Roundness

This term is not recommended. The term Ovality is preferred.

Rub, Tool

A surface area showing a scratch or abrasion resulting from contact of the hot extrusion with the press equipment or tooling or, in the case of multi-hole dies, with others sections as they exit the press.

Run, Statistics

A consecutive number of points consistently increasing or decreasing, or above or below the central line. Can be evidence of the existence of special causes of variation.

Runout Table

Table at immediate exit of press leadout equipment which helps to guide and support the extrusion.