MSE 258:Physical Metallurgy of Non-Ferrous Metals

Dr. Emmanuel Kwesi Arthur

Department of Materials Engineering,

Kwame Nkrumah University of Science and Technology, Kumasi

2019

Lecture Two

‘Ferrous metal’ or ‘Ferrous alloy’

What is a ‘ferrous metal’ or ‘ferrous alloy’? It is simply a metal or alloy that contains Iron (the element ferrous) as the base (starting) metal.

Approximately 90% of the world’s production of metals/alloys are ferrous because of their good strength, toughness, ductility and relatively low cost.

26th element

Iron or Ferrous

55.85 Atomic Mass

Nonferrous metals offer a wide variety of mechanical

properties and material characteristics.

Nonferrous metals are specified for structural

applications requiring reduced weight, higher strength,

nonmagnetic properties, higher melting points, or

resistance to chemical and atmospheric corrosion.

They are also specified for electrical and electronic

applications.

Nonferrous metals

Quiz 1

1) What is the main difference between ferrous and non ferrous metals?

2) What is pewter used for? 3) Give two examples of an alloy4) Give two examples of a non-ferrous metal.5) Give two examples of a ferrous metal.

World consumption

Aluminium, titanium and magnesium alloys are increasingly used in recent years due to its attractive properties.

The reserves for these alloys are adequate for demands in centuries to come but will be controlled by future cost.

World production figure for various metals and plastics.

Total energy consumption for the production of nonferrous metals

Total energy consumption

Total energy consumption in megawatt hours for each stage of production (1993).

Fact- About 6.2kWH of electricity is required to produce one pound of aluminium from alumina

1. General (heavy) non-ferrous metalsa) with medium melting temperature: Cu, Ni, Co, Mnb) with low melting temperature: Zn, Cd, Hg, Pb, Bi, Sn, Sb, Ga, In, Tl

2. Light metalsa) with medium melting temperature: Al, Mg, Be, Ca, Sr, Bab) with low melting temperature (alkali metals): Li, Na, K, Rb, Cs

Note: some authors consider even Ti-4.5 g/cm3

3. Noble (precious) metalsa) with medium melting temperature: Ag, Aub) with high melting temperature: Ru, Rh, Pd, Os, Ir, Pt

Non-ferrous metals and their alloys

Cu Ni Co Mn Zn Cd Hg Pb Bi

Tm oC 1085 1455 1495 1246 419.5 321.1 -38.83 327.5 271.4

Sn Sb Ga In Tl Al Mg Be Ca

Tm oC 231.9 630.6 29.76 156.6 304 660 650 1287 842

Sr Ba Li Na K Rb Cs Ag Au

Tm oC

4. High melting temperature metalsa) with BCC lattice: W, Ta, Nb, Mo, V, Crb) with HCP lattice: Ti, Zr, Hf, Tc, Re

5. Rare earth metalsa) trace metals: Sc, Y, Lab) Lanthanides (at. no. 58-71): Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er,

Tm, etc.6. Radioactive metals, transuranides and transactinides

a) naturally occurring radioactive metals: Po, Fr, Ra, U, Th, Pa, Acb) transuranides and actinides (at. no. 93-103): Np, Pu, Am, Cm, Bk, Cf, Es,

Fm, Md, No, Lrc) transactinides and superactinides (at. no. 104-168): Rf, Db, Sg, Bh, Hs,

Mt, Ds, ....?

Non-ferrous metals and their alloys

Classification of non-ferrous materials

a) Density based:

– light metals and alloys ρ < 5000 kg/m3 (Mg, Al, Ti)

– medium metals and alloys ρ = 5000...10000 kg/m3 (Sn, Zn, Sb, Cr, Ni, Mn, Cu)

– heavy metals and alloys ρ >10000 kg/m3 (Pb, Ag, Au, Ta, W, Mo)

b) Melting temperature based:

– low melting point Tm < TmPb = 327 °C (Sn, Pb, Bi)

– medium melting point = 327…1539 °C (Al, Mg, Mn, Cu, Ni, Co, Ag, Au)

– refractory Tm > TmFe = 1539 °C

11

Element Ti Cr V Nb Mo Ta W

Tm, °C 1660 1875 1900 2415 2610 2996 3410

Aluminum and Aluminum Alloys

Aluminum is an extremely useful engineering material as:o They are light weight and strong; Al has a density

of 2700 kg/m3, which is about 1/3 that of steel. o Their strength to weight ratio is excellent.o Al is non-toxic.o Al is one of the best metal electrical conductorso Al has good corrosion resistance due to its natural

oxide layer, which is thin and passive once formed.o Aluminum has ease of formability and of

machinablity and it is non magnetic

Quiz 2

1. Where do metals originate from? [1]2. Describe what a ferrous metal is? [1]3. Describe what a non ferrous metal is? [1]4. Describe what an alloy is? [1]5. How are alloys produced that have different

properties? [1]6. Explain the following properties:

Brittleness [1]Elasticity [1]Malleability [1]