Physical Properties of Metals and Alloys

Question 1

Define METALS?

Answer 1

an alloy or mixture composed wholly or partly of such substances.

Question 2

Define LUSTRE

Answer 2

This a measurement of the ability of the surface of a metal to reflect light. The reflected light is affected by surface oxidation in some metals.

Question 3

DENSITY

Answer 3

The density of metals varies enormously, from metals such as depleted Uranium or Tungsten. It is generally considered that the strength to weight ratio is more important in selecting the right metal for a particular application than purely weight.

Question 4

HARDNESS

Answer 4

Hardness is the measure of a metals ability to resist deformation.

Question 5

CONDUCTIVITY

Answer 5

The conduction of both heat and electricity.

Question 6

MALLEABLE

Answer 6

Capable of being extended by beating with a hammer or by rollers.

Question 7

DUCTILE / DUCTILITY

Answer 7

Capable of being drawn out without breaking. Also capable of being moulded without breaking.

Question 8

explain the ANODISE process?

Answer 8

Anodising is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts.

Question 9

IRON

Answer 9

A heavy, ductile, malleable, magnetic element most common on earth

Question 10

COPPER

Answer 10

Metallic element that is ductile and malleable and one of the best conductors of heat and electricity.

Question 11

What is copper used for in ammunition?

Answer 11

Driving Bands, Detonators, Shaped charge liners, Cartridge Cases, SAA jackets (gilding Metal)

Question 12

ALLOYS

Answer 12

Alloys are metallic substances that contain more than one chemical element.
are sub divided into ferrous alloys (those that contain iron) and non ferrous alloys (those that do not contain iron).

Question 13

BRASS

Answer 13

Yellow alloy of copper and zinc, sometimes other metals that is malleable and ductile and harder and stronger than copper.

Question 14

Brass is not?

Answer 14

Brass is not magnetic.

Question 15

Brass is susceptible to what three things?

Answer 15

Brass is susceptible to stress corrosion cracking.
The problem is sometimes known as season cracking.

Question 16

Cartridge brass makeup percentage?

Answer 16

Cartridge Brass 70% Copper 30% Zinc

Question 17

Corrosion and Season Cracking

Define season cracking

Answer 17

Stressed areas of metal cracking due to the affect of ammonia forming Cuprammonium during storage in either hot or cold temperatures.

Question 18

Types of corrosion

Answer 18

• Rust (Ferrous Oxide) - Projectiles
• Aluminium Oxidation - Tail fin assemblies of (mortar)
• Mazak contamination (Magnesium, Aluminium, ZInc, Copper) (Fuze bodies)
• Cupric Azide (detonators and fuzes)
• Zinc exudation

Question 19

When are stresses most likely to be formed in metal & what can aggravate them?

Answer 19

The stresses may be formed in the metal during manufacture and which may be further aggravated by the environmental changes