Chapter 4

Alloys

Unit 1

Text 1

Bronze and Brass

About 6,000 years ago people discovered that copper could be made harder if mixed with tin. This alloy is called bronze. It was so widely used for many years that this period of time became known as the Bronze Age.

If you had been a soldier in Ancient Greece you would have had to stop in battle to straighten your bronze sword. But bronze was a great improvement on copper, which bends even more easily. Most pure metals are weak and soft. But two soft metals mixed together make a harder metal called an alloy. Bronze is an alloy of copper and tin. It was the first alloy.

Tin was the fifth metal discovered by man. It is a soft whitish substance. Various proportions of the two metals produced different qualities in the bronze. Most early metal-workers used about eight parts of copper to one of tin. Because weapons made of bronze were harder and stronger than those of copper, tin became very important. However, there was little tin to be found in western Asia - still the centre of the metal-working world. Mostly it was found in Europe, and the merchants of Troy, who brought their goods to Europe, began loading their boats with tin on their return journeys. In England, tin was discovered and mined in Cornwall and was a main export for a long time.

When zinc was discovered it was used to produce an important alloy in combination with copper. This alloy was brass, a hard-wearing, yellow metal which was valued more than bronze. The exact date of discovery is uncertain but it was probably about 200 BC. Brass is often mentioned in the Old Testament, most of which was written before zinc was discovered and therefore when there could not have been any brass. The bibical metal must have been either bronze or copper, and the word ‘brass’ is the result of a translator’s error at some time. So, bronze and brass were the first alloys - man-made metals.

Task 1. Phonetic Exercise

Practise after the speaker and learn to pronounce the words given below.

straighten /’streitn/; Asia /’ei/; Europe /’jurp/; load /loud/; brass /bra:s/; export /’ekspo:t/; biblical /’biblik l/.

Task 2. Lexical Exercises

Exercise 1. Find the English equivalents for the words and word- combinations given below.

большинство чистых металлов; сплав; мягкий металл беловатого цвета; оружие, сделанное из бронзы; Бронзовый век; износостойкость; упоминать; ошибка; добывать олово.

Exercise 2. Match the English words and word-combinations given below

with their Russian equivalents.

1. mixed with tin 1. либо бронза, либо медь

2. return journey 2. до нашей эры

3. a main export 3. в сочетании с

4. BC (before Christ) 4. в сочетании с оловом

5. the Old Testament 5. обратное путешествие

6. in combination with 6. Ветхий Завет

7. either bronze or copper 7. основной предмет экспорта

Exercise 3. Answer the following questions

1. Why was bronze a great improvement on copper? 2. What does bronze consist of? 3. Where were the major tin deposits located? 4. What alloy was produced of zinc in combinations with copper? 5. Why was brass valued more than bronze?

Exercise 4. Look through the text and find the words which mean

the same as:

find out; arms; so; in combination with; way back; mistake;

advance; principle.

Exercise 5. More about word-building: Adverbs.

Rule: to change an adjective into an adverb add -ly:

close - closely; easy - easily; heroic - heroically

Certain other words have the same form whether they are adjectives or adverbs:

a fast train - it came fast

a short time - he stopped short

an early bird - he rose early

a hard worker - he works hard

a close decision – he came close

Change the following adjectives into adverbs:

firm; usual; punctual; hard; manual; graphic; early; economic; normal; heavy; synthetic; extravagant; careful; wonderful; fast.

Exercise 6. Translate at sight.

1. Shaping of Metals. The last stage in smelting usually involves the casting of the metal into a mould. This mould may be shaped to the form desired in the finished article, the process being known as founding or casting. On the other hand the metal may be cast into a mould of simple form such as an ingot for subsequent shaping by such mechanical working methods as forging, rolling, extrusion, etc.

2. Requirements for blast furnace performance have increased dramatically over the last 15 years. Productivity and daily output must be high: downtime must be minimal. Operating and maintenance cost must be as low as possible. Campaign life of a blast furnace can last as long as 15 years nowadays, without any major repair.