Mechanical Properties

Question 1

malleability

Answer 1

the ability of a material to withstand deformation by compression (before it shows sign of cracking) e.g copper — malleability increases with temp. and therefore metals which need to be bent, rolled or extruded, are heated first

Question 2

ductility

Answer 2

the ability of a material to be drawn out, can be deformed under tensile stress, (ability to be stretched into a wire) e.g copper

Question 3

toughness

Answer 3

the ability of a material to withstand sudden impact without fracture (can also refer to withstanding bending), opposite to brittle

Question 4

elasticity

Answer 4

the ability of a material to flex and bend when forces are applied and to regain normal shape and size when those forces are removed

Question 5

plasticity

Answer 5

the ability of a material to be permanently changed in shape by external forces e.g hammer blows, pressure, without cracking, metals and thermoplastic polymers tend to generally be more plastic when heated

Question 6

hardness

Answer 6

the ability of a material to resist abrasive wear, indentation or formation, important property of cutting tools e.g drills

Question 7

durability

Answer 7

the ability of a material to withstand wear and teach, weathering and the deterioration or corrosion this may cause, weathering can results in mechanical weakening

Question 8

stability

Answer 8

the ability of a material to resist changes in size and shape due to its environment, e.g timber tends to warp and rot due to changes in humidity, metals and some plastics deform subject to continual stress: these processes are known as ‘creep’

Question 9

strength

Answer 9

the ability of a material to withstand force without breaking or permanently bending

Question 10

tensile strength

Answer 10

the ability of a material to resit stretching or pulling forces

Question 11

compressive strength

Answer 11

the ability of a material to withstand pushing forces which attempt to crush or shorten the material

Question 12

bending strength

Answer 12

the ability of a material to withstand forces with attempt to bend the material

Question 13

shear strength

Answer 13

the ability of a material to resist sliding forces acting against each other

Question 14

torsional strength

Answer 14

the ability of a material to withstand twisting forces under torsion or torque

Question 15

magnetism

Answer 15

a property possessed by many elements, and is the product of the orientation of electrons about their atoms, only a few elements are strongly magnetic