Materials

What is the positively charged particle in an atom is called

Proton

In the periodic table rows are known as

Periods

If a tensile test specimen fractured with no visible necking and with a fracture that was perpendicular to the axis of the specimen this would indicate

A brittle material

Dye penetrant testing is generally used in which situation

To find surface cracking

What are valence electrons?

Electrons in the outer most shell of an atom

What are the two main alloying elements of brass?

Copper and Zinc

What is the major alloying element of AISI 5140 Steel?

Chromium

what is the percentage of carbon in cast iron?

2 to 4.5

What is the ability of a material to resist fracture due to high impact loads called?

Toughness

Which quenching media gives the highest cooling rate?

Brine

What is pearlite?

Ferrite and Cementite

What category of polymers is polypropylene?

Thermoplastic

Hot working process of steels are carried out at

Above the temperature at which recrystallisation occurs

Generally, thermoplastic polymers or plastics have lower strengths than metals or ceramics. This is mainly due to

Weak Van der Waals bonds between chains

What is the alloying content of high alloy steels?

Greater than 5%

What is the ability of a material to harden to certain depth called?

Hardenability

______ is measured from the slop of the straight section of the graph.

Elastic modulus (Young’s modulus)

A ______ is a material made from two or more other materials with properties that are superior to the properties of the starting materials

Composite

What heat treatment process would normally be used to improve the toughness of a fully hardened steel specimen?

Tempering

In the periodic table, what are known as columns?

Groups

What is Martensite

Body centered tetragonal iron with trapped carbon atoms

What are the two main alloying elements of bronze?

Copper and Tin

What is the nominal carbon content of AISI 5120 steel?

0.20%

Mohs and Rockwell are common _______ testing techniques.

Hardness

In quench hardening all materials must start as ______.

Austenite

______ is a crystalline ceramic, used as insulation material in heating elements

Aluminium oxide

What is the negatively charged particle in an atom is called?

Electron

What is the definition of ductility?

The ability to be stretched into long forms without cracking

A ______ is a material with its atoms held together by free electrons in the lattice.

Metals

What is matter?

something that has weight & occupies space

What is the permanent mode of deformation of a material known as?

Plasticity

Which quenching media gives the slowest cooling rate?

Oil

What is the ability of materials to develop a characteristic behaviour under repeated loading known as?

Fatigue

What category of polymers is polystyrene?

Thermoplastic

In quench hardening, the hardest structural phase of steels is

Martensite

______ is used to make soft drink bottles

PET

What is Allotropism

a material which exhibits more than one crystal structure

What is the nominal carbon content of AISI 4140?

0.04%

Fatigue is usually associated with metals that are subjected to

Cyclic loads