From Past Exams

Alloy

a substance with metallic properties, composed of two or more elements of which at least one is metal.

Embrittlement

the loss of ductility because of a physical or chemical change of the material

Aging

change in a metal by which its structure recovers from an unstable meta stable condition that has been produced by quenching or col working

Hardening

heating of certain steel above the transformation range and then quenching

Transverse stress

in a thin walled pressure vessel it is the stress in the longitudinal section

Nylon

expensive thermoplastic with load carrying capacity up to 250deg F has low coefficient of friction and good wear resistance used for bearings and machined or molded

Brass

alloy of copper an zinc

Polar section modulus

the ratio J/c is called

Bronze

alloy of copper and tin

Tolerance

permissible variation of the size of a dimension

Strain

deformation per unit length

Spheroidizing

any heating & cooling of steel that produces a rounded or globular form of carbide

Chromium

improves hardenability economically, resistance to corrosion, strength at high temp and wearing properties

Annealing

heating & slow cooling of solid metal, usually done to soften it

W

chemical formula of tungsten

Transverse stress

also called rupture modulus

Residual Stress

Those stresses not due to applied loads or temp gradients; they exist for various reasons, as unequal cooling rates, cold working etc.

Ultimate Stress or Tensile Strength

highest point on the stress-strain curve. It is the maximum load divided by the original area before straining occurs.

Transformation Range

the temperature interval during which austenite is formed during heating

Modulus of Elasticity

a measurement of stiffness. Refers to Young’s modulus

z - I/c

section modulus

Normalizing

the heating of an iron-base alloy to some 100°F above the transformation range with subsequent cooling below that range in still air at room temperature.

Tempering

a reheating of hardened or normalized steel to a temperature below the transformation range, followed by any desired rate of cooling.

Transverse Mod

It is the modulus of elasticity in shear or modulus of rigidity

33 000

1HP is equal to what in ft lb/min

Torque

also called twisting moment

Wrought Steel

steel that has been hammered, rolled, or drawn in the process of manufacture; it may be plain carbon or alloy steel.

Free cutting

11xx

Cold Working

the process of deforming a metal plastically at a temperature below the recrystallization temperature and at a rate to produce strain hardening.

Damping Capacity

the ability of a material to absorb or damp vibrations, which is a process of absorbing kinetic energy of vibration owing to hysteresis.

Percentage Reduction of Area

the smallest area at the point of rupture of a tensile specimen divided by the original area.

Rimmed Steel

incompletely deoxidized steel.

Hard Drawn

a temper produced in wire, rode, or tube by cold drawing.

Torsional Shear

the name of stress if the member is under torsion

Isotropic Materials

have the same properties in all directions.

Izod Test

a test in which a specimen, supported at one end is a cantilever beam, is broken by the impact of a falling pendulum.