Methods for investigating and testing materials.

Question 1

How to test the tensile strength of a material?

Answer 1

-Place into Tensometer machine
-One side is fixed and the other is on a worm driven mechanism.
-As the material is stretched apart from itself, the load and distance travelled is plotted giving the elastic limit, yield point, maximum load and final breaking point after “necking”

Question 2

How to test the toughness of a material?

Answer 2

-Notched piece placed vertically in the vice of the machine
-A pendulum is released from a set position to strike and hit the material.
-The energy absorbed by the material is calculated.
-The material that absorbs the most impact is the toughest.
-The further the pendulum swings, the less energy the sample absorbs and the more brittle the material.

Question 3

How to test the hardness of the material?

Answer 3

Brinell test: A hardened standard sized ball is forced into the material’s surface using a pre-set load. The diameter of the indent is then measured. The smaller the diameter of the indent, the harder the material.

Question 4

How to measure the ductility and malleability of a material?

Answer 4

-A test piece is placed into a bending machine and held, supported at the ends.
-A mandrel or plunger loads the test piece at the centre and bends it to a predetermined angle or until the piece fractures.
-Cracks on the outer bend indicate the level of ductility
-Cracks on the inside bend indicate malleability.