elements of physical metallurgy of non-ferrous metals- classification, physical, chemical and...

Elements of physical metallurgy of non-ferrous metals-classification, physical, chemical and mechanical properties of some important aluminium, titanium, copper and other important non-ferrous alloys.

Heat treatment of some non-ferrous alloys and their applications

Syllabus

Human beings are one of the most defenseless animals. We lack sharp teeth, claws, speed, etc.

What we do have is a superior brain. Make tools to compensate for what we don’t

have.

Bones, animal teeth, stones, and wood are some materials used.

It is believed that man first discovered gold and silver. They found these metals beautiful, but too

soft to be used for anything utilitarian (having a useful function).

About 10,000 years ago man discovered and used another metals- copper Soft- used for decorations

Around 3800 B.C- man discovered tin Useless in its raw form Alloyed with Copper, a tough metal was created

Metal Alloys are a mixture containing two or more metallic or non-metallic elements usually fused together when in a molten form.

Birth of the Bronze age.

Eventually mankind discovered iron ore, and developed the techniques for extracted iron from that ore.

Iron age was born around the 12th century B.C.

Humans experimenting with iron forging techniques developed the first iron alloy- steel. Steel is an alloy between iron and

carbon. Other metals are added to modern steel

for strength and higher melting point.

How does the history of the discovery of metals relate to chemistry?

One way to study the reactivity of metals is to test how they react with oxygen Oxygen is plentiful Need for combustion.

Copper vs. Magnesium Demo Compare this to gold.

Does Au tarnish easily?

Rank the reactivity of Au, Cu, and Mg? Which do you think will be used for

jewelry, and for the wires and electrical contacts in expensive electronic devices, and car air bags?

Notice that Lithium is at the top of the list Most reactive metal

Never found free in nature Extracted by expensive electrometallurgical

extraction Electricity passed though ore Expensive to store: highly reactive with air

Gold is at the bottom of the list Least reactive

Used in jewelry, sensitive electrical components, art Can be found free in nature or in ore Extracted by heating ore

What determines how metals are found in nature?

Reactivity More reactive metals found in ores.

Harder/ more difficult to process Less reactive metals found “free”

Easier to process

In general, atoms of a more reactive metal (higher on the table) will cause ions of a less reactive metal to be converted to its metallic form.

Do you see the relationship between how reactive a metal is, and when it was discovered by man?

Do you see the relationship between how reactive a metal is, and how difficult it is to extract?

1. What trend in metallic reactivity to you see as you go from left to tight across a period?

2. Where are the most reactive metals on the P.T.?

3. Where are the least reactive metals found on the P.T.?

4. Will iron metal react with a Lead (II) nitrate solution? Explain.

5. Will platinum metal react with the lead (II) nitrate solution? Explain.

6. Which are less expensive, more reactive or less reactive metals? Why would reactivity influence the price?

The term non-ferrous alloys are used for those alloys which do not have iron as the base element. Generally, the non-ferrous alloys commonly used in engineering application are Aluminium alloys, Copper alloys, Magnesium alloys, Titanium alloys etc.

NONFERROUS ALLOYS

5.1 TYPES OF METAL ALLOYS

Low Alloy steels are usually considered to be those containing a total of less than 5% of such added constituents.

Ferrous alloys include steels and cast irons.

Metal alloys are often grouped into two classes –ferrous and nonferrous.

The advantages of Non-ferrous alloys over ferrous alloys are

as follows:

a)  Good resistance to corrosion without special processes having to be carried out.

b)  Most non-ferrous alloys have a much lower density and hence lighter weight components can be produced.

c) Casting is often easies because of the lower melting points.

d) Cold working processes are often easier because of the greater ductility.

e) Higher thermal and electrical conductivities.f) More decorative colours.

Non-ferrous metals can be improved the mech. properties by using solution treatment, ageing & precipitation hardening, as shown in figure below.