Chapter 5: Mechanical Properties of Metals

Metals are known to be:

how much force an object can withstand without bending or breaking (compression, tension, & shear)

refers to a material’s response to tensile stress, or its ability to be stretched, rolled or extruded without breaking.

refers to a material’s response to tensile stress, or its ability to be stretched, rolled or extruded without breaking.

refers to compressive stress, as in flattening.

important properties of metals

represents an ideal balance between strength and ductility. The toughest metals are those that can absorb the highest amounts of energy before fracturing. In simple terms, the toughest parts are the most difficult to break

is a measure of a part’s ability to undergo repeated, cyclical stress without fracturing or permanently deforming.

A material’s power to resist a permanent change in shape when acted upon by an external force

Crystalline Structure of Metals

mechanical properties of FCC

mechanical properties of BCC

mechanical properties of HCP

The ___ of a material reflects its response or deformation in relation to an applied load or force.

Key mechanical design properties are

One of the most common mechanical stress–strain tests is performed in

It is conducted in a manner similar to the tensile test, except that the force is compressive and the specimen contracts along the direction of the stress. Same equation use in strain and stress as in tension. Used when a material’s behavior under large and permanent (i.e., plastic) strains is desired, as in manufacturing applications, or when the material is brittle in tension.

is a variation of pure shear in which a structural member is twisted in the manner of torsional forces produce a rotational motion about the longitudinal axis of one end of the member relative to the other end.

is a function of the orientations of the planes upon which the stresses are taken to act.

a more complex stress state is present that consists of a tensile (or normal) stress 𝜎 ′ that acts normal to the p-p’ plane and, in addition, a ___ that acts parallel to this plane; both of these stresses are represented in the figure.

is non-permanent, which means that when the applied load is released, the piece returns to its original shape. As shown in the stress–strain plot Upon release of the load, the line is traversed in the opposite direction, back to the origin.

With increasing temperature, the modulus of elasticity ___

defined as the ratio of the lateral and axial strains

In most metals, G is about ___