Question

Match the following major alloying elements in aluminum alloys with the appropriate series (e.g., a-1) Mn 7xxx Mg 2xxx Zn 4xxxSi 3xxx Cu 5xxx What does aluminum 3003-H24 designation mean? What does aluminum 6061-T6 designation mean? What happens metallurgically in the thermal and natural aging cycles? What is the difference between anodizing and hard coating?

Answer 1

Question 1

d-3

a-4

c-1

b-5

e-2

Question 2

Different designations are given for identification purpose.The four digit number identifies athe major element alloyed with aluminium.H2 refers to strain hardened and partially annealed.Second digit refers to degree of hardness.Here 4 refers to half hardened.

Question 3

6000 series means it aluminium is alloyed with magnesium and silicon6061 means precipitation hardened aluminium alloy.T refers to thermal treatment to produce stable tempers.The digit refers to the fact that it is solution heat treated and artificially aged.

Question 4

Aging is done to enhance the strength of the alloy.

Aging which occurs at room temperature is natural whereas by heat treatment is thermal aging.

Aging restores the equilibrium in the metal by eliminating unstable conditions imposed by prior treatments given

Question 5

Coating of the metal with paint or other coating materials on the metal surface is called hard coating. This coating may comeout as flakes or peeled off.

Anodizing is an electro-chemical process of smooth even coating of aluminium oxide on the surface. Unlike hardening, anodized material has high durability and corrosion protective in nature,