VII. Discuss with your partner which sentence in b best continues the sentence in a.

A B

1. Casting is a process a) a skin of solid metal is formed over the still liquid

2. Casting can be referred to center.

3. Casting has b) into expendable and non-expendable casting.

4. The casting process is subdivided c) advantages in the production of complex shapes.

5. Expendable mold casting includes d) creates its own force feed.

6. Non-expendable mold casting e) made from non-ferrous metals.

7. Permanent mold casting f) aluminum, magnesium, and copper alloys.

8. Common casting metals are g) molten metal under high pressure into mold cavity.

9. The die casting process forces h) sand, plastic, shell, plaster and investment moldings.

10. Most die castings are i) includes permanent, die, centrifugal, continuous casting.

11. Centrifugal casting j) employs reusable molds.

12. During continuous casting k) where a solid is melted and heated to proper

temperature.

13. Casting has l) products made out of melted iron molecules.

VIII. What do the numbers refer to?

20.000, 2, an inch, 30 feet

IX. Talk about casting from memory using these prompts:

• pouring a liquid metal

– casting

• casting properties

• casting process

• expendable casting

• nonexpendable casting

• permanent mold casting

• die casting process

• centrifugal casting

• continuous casting

Part II

I. You are going to read the text about two types of casting. For the questions choose from the types of casting (A–B). There may be more than one answer.

Which of the casting methods

– uses gold?

– is the same as common mold casting?

– can afford a new casting every day?

– gives you an option to make your own design?

– produces parts with good dimensional accuracy?

– reduces the production time?

– increases the tensile strength of the metal?

– is expensive?

– makes metal porous?

– should be handled with most care?

Die casting is the method used for forcing molten metal into mold cavities under high pressure. Die casting is the same as permanent mold casting. The only difference is that the metal is injected into the mould at very high pressure of 10-210 Mpa. This results in a more uniform part, usually good dimensional accuracy and also good surface finish. The different metals and alloys that can be used in die casting are zinc, aluminum, copper, magnesium, tin and lead. Ferrous metals can also be used for die casting. Die casting method is generally used when medium or small sized parts are required with detail, good dimension and fine surface finish.

There are namely two equipments used for die casting cold chamber and hot chamber process. Molten metal is a huge part of the cold chamber process as you get to fill a cold chamber of each module with this molten metal. The time exposure provided for the molten metal to plunge the walls of the mold is less. This clod chamber process method is very useful for metals like aluminum, copper and metals that easily alloy with iron at high temperatures.

Advantages of die casting: The method of die casting gives excellent dimensional accuracy. The dimensional accuracy is as good as 0.1mm for the first 2.5cms and 0.005 for the first inch. Smooth cast surfaces can also be provided with die casting. Small and thin walls can be made using the method of die casting .Walls as tiny as 0.75mm can be cast. Inserts like thread insert, high strength bearing surfaces and heating elements can also be inserted using the die casting method. Metal Casting also helps in reducing or even completely eliminating the use of secondary machining operations. The use of die casting method also helps to reduce the production time and a huge number of articles can be produced in a very short time. Die casting method also helps to retain as well as increase the tensile strength of the metal.

Disadvantages of die casting: The casting weight is less hardly between 30 grams and 10 kgs. Die casting can really take money out of your wallet quickly because it has a high initial cost. Die casting method makes the metal porous up to some extent. In the die casting method the thickest section needs to be less than 13mm or 0.5 inches.

Casting Jewelry is a process in which liquid material made from heating metals, is poured in a module, to give the liquid a desired shape. Then the liquid is cooled and a solid object in the desired shape and size is obtained. This jewelry is made from different materials like silver, aluminum, gold, bronze, alloy metals. Casting Jewelry is very attractive and delicate. They are made using machines, but very finely crafted and hand made jewelry is also available in the market. This type of jewelry can be available at a very low, as well as high costs, depending on the design and material and design that you choose. Casting Jewelry is very fragile and should be handled with most care as it can break easily. With the advent of casting jewelry, the fashion world has benefited a great deal. Today, free flowing designs, multicolored jewelry and even a special made to order jewelry is available in the market.

Before this, it was difficult to cast a metal in a desired shape but today it is as simple as it gets, all you need is a creative mind to create new designs and a group of well qualified workers and good machinery to make your own casting jewelry. This also gives you an option to make your own series of new designs. Casting Jewelry is now used just about everywhere on the globe. With the prices of gold increasing day by day and with the entry of new metal jewelry like platinum, casting jewelry slowly but surely is making a mark in the fashion world. The dream of wearing a new necklace or a new ear-ring everyday is a reality. You can actually afford new set of jewelry everyday. There are also costly models made of pure gold and delicate designs and with embedded diamonds that are available.

Part III