choose the property thatd makes the following materials useful

Thermal Conductivity is a measure of the quantity of heat that flows through a material. It is measured as one degree per unit of time, per unit of cross-sectioned area, per unit of length.

2. Corrosion Resistance

Corrosion’s ability to prevent natural chemical or electro-chemical attack by atmosphere, moisture or other agents. Corrosion takes many forms including pitting, galvanic reaction, stress corrosion, parting, inter-granular, and others (many of which will be discussed in other newsletter editions).

3. Density

Density, often expressed as pounds per cubic inch, or grams per cubic centimeter, etc., describes the mass of the alloy per unit volume. The density of the alloy will determine how much a component of a certain size will weigh.

4. Ductility / Malleability

Ductility is the ability of a material to deform plastically (that is, stretch) without fracturing and retain the new shape when the load is removed. Think of it as the ability to stretch a given metal into a wire.

Malleability, a physical property, describes a metal’s ability to be formed without breaking. Pressure, or compressive stress, is used to press or roll the material into thinner sheets.

5. Elasticity, Stiffness

Elasticity describes a material’s tendency to return to its original size and shape when a distorting force is removed. As opposed to materials that exhibit plasticity (where the change in shape is not reversible), an elastic material will return to its previous configuration when the stress is removed.

The Stiffness of a metal is often measured by the Young’s Modulus, which compares the relationship between stress (the force applied) and strain (the resulting deformation). The higher the Modulus – meaning greater stress results in proportionally lesser deformation – the stiffer the material.

6. Fracture Toughness

Impact resistance is a measure of a material’s ability to withstand a shock. The effect of impact – a collision that occurs in a short period of time – is typically greater than the effect of a weaker force delivered over a longer period.

7. Hardness

Hardness is defined as a material’s ability to resist permanent indentation (that is plastic deformation). Typically, the harder the material, the better it resists wear or deformation. The term hardness, thus, also refers to local surface stiffness of a material or its resistance to scratching, abrasion, or cutting.

8. Plasticity

Plasticity, the converse of elasticity, describes the tendency of a certain solid material to hold its new shape when subjected to forming forces. It is the quality that allows materials to be bent or worked into a permanent new shape. Materials transition from elastic behavior to plastic at the yield point.

9. Strength – Fatigue

Fatigue can lead to fracture under repeated or fluctuating stresses (for example loading or unloading) that have a maximum value less than the tensile strength of the material. Higher stresses will accelerate the time to failure, and vice versa, so there is a relationship between the stress and cycles to failure.

10. Strength – Shear

Shear strength is a consideration in applications like bolts or beams where the direction as well as the magnitude of the stress is important. Shear occurs when directional forces cause the internal structure of the metal to slide against itself, at the granular level.

11. Strength – Tensile

One of the most common metal property measures is Tensile, or Ultimate, Strength. Tensile strength refers to the amount of load a section of metal can withstand before it breaks. In lab testing, the metal will elongate but return to its original shape through the area of elastic deformation. When it reaches the point of permanent or plastic deformation (measured as Yield), it retains the elongated shape even when load is removed.

12. Strength – Yield

Similar in concept and measure to Tensile Strength, Yield Strength describes the point after which the material under load will no longer return to its original position or shape. Deformation moves from elastic to plastic. Design calculations include the Yield Point to understand the limits of dimensional integrity under load.

13. Toughness

Measured using the Charpy impact test similar to Impact Resistance, toughness represents a material’s ability to absorb impact without fracturing at a given temperature. Since impact resistance is often lower at low temperatures, materials may become more brittle.

14. Wear Resistance

Wear resistance is a measure of a material’s ability to withstand the effect of two materials rubbing against each other. This can take many forms including adhesion, abrasion, scratching, gouging, galling, and others.