5.Alloys

When two or more metals or non-metals are combined together and intimately mixed by fusion, electrolytic deposition, etc. the final product or alloy formed is stronger and more durable for practical use, as compared to the base metal. The different metals that are used to prepare alloys are zinc, copper, tin, aluminum, chromium, nickel, silver, etc. Moreover, the different non-metallic elements used to make alloys are carbon, boron, sulfur, zinc, etc. Depending on the composition of metal or non-metal in the alloy, we have different types of alloys.

There are scores of different types of alloys that are prepared from a combination of metals and non-metals. There can be different types of alloy metals, such as binary alloys, which are created by combining two materials, either two metals or one metal and one non-metal or ternary alloys, that are created by combination of three elements. For an alloy to be formed, the presence of at least one metal is essential.

The name stainless steel is commonly referred to those metal alloys comprising 10.5% or more Chromium (Cr) and 50% Iron (Fe) in it. The chromium present in it gives stainless steel its highly corrosion resistant property. Pure iron is unstable and corrodes naturally by rust formation. By the addition of chromium, iron is prevented from combining with oxygen and water to form rust. This highly stain resistant alloy looks bright because of its ability to reflect light. There are different types of stainless steel depending on the amount of chromium, iron and other metals in them.

Task 1. Say whether these sentences are true or false

1. An alloy usually has the same properties as the combined substances.

2. Only a combination of metals may be an alloy.

3. There can be different types of alloys.

4. The chromium does not effect the properties of steel.

5. Highly stain resistant alloy usually looks bright.

Task 2. Make the sentences complete:

When two or more metals or non-metals are combined together	a) and corrodes naturally by rust formation
The different metals that are used to prepare alloys are	b) the presence of at least one metal is essential.
For an alloy to be formed	c) those metal alloys comprising 10.5% or more Chromium (Cr) and 50% Iron (Fe) in it
The name stainless steel is commonly referred	d) the final product or alloy is formed
. Pure iron is unstable	e) zinc, copper, tin, aluminum, chromium, nickel, silver, etc.

Task 3.Mach the term with its definition.

metal	a)the process of corroding metal, stone, or other materials
2. fusion	b) a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity
3. corrosion	c)a colorless, odorless reactive gas
4. rust	d) the process or result of joining two or more things together to form a single entity
5. oxygen	3)a reddish- or yellowish-brown flaky coating of iron oxide

Task 4. Fill in the gaps:

There are scores of __1__types of alloys that are prepared from a __2___of metals and non-metals. There can be different types of alloy metals, such as __3___ alloys, which are created by combining __4___ materials, either two metals or one metal and one non-metal or ternary alloys, that are created by combination of three ___5__. For an alloy to be formed, the presence of at least one metal is essential

A combination; B elements; C two ; D binary; E. different;