Chapter Four

1) Contrast the process flow of vacuum casting and pressure casting in permanent die casting process.

(4 marks)

2) Explain four (4) types of defects that are usually occurs in sand casting process.(4 marks)

3) Split pattern and match plate pattern are the most commonly used sand casting pattern. Compare the design characteristics of split pattern and match plate pattern and illustrate the design.

(2 marks)

4) Green sand mold are made of a mixture of sand, clay and water. Explain the four indicators used to determine the quality of the green sand mould.

(2 marks)

5) For your opinion, why investment casting are preferable compare with other casting processes?

(2 marks)

6) Core can be used in permanent mold to form interior surface in the cast product.Explain the steps in permanent mold casting with used cores. Support your explanation with illustration.

(4 marks)

7) Foundries are a source of many hazards. List four (4) and explain the function personal protective equipment (PPE) to protect workers from the foundry environment.

(2 marks)

8) Varieties of materials can be used for casting components and there are number ofdifferent casting techniques involved. Explain the advantages and limitation of thesecasting techniques.

(3 marks)

9) Generally there are two (2) types of casting; expendable and permanent mouldcasting. Describe the differences between expendable and permanent mould casting.

(3 marks)

10) Briefly explain Die casting process and name two (2) common products that can beproduced by this process.

(4marks)

11) Briefly specify the advantages of sand casting process over other casting processes and give an example of product in each case.

(4 marks)

12) Small automotive components such as gear, valves and cams are usually made by means of investment casting process. Illustrate the steps taken in investment casting process and why this process suitable in producing small components?

(5 marks)

13) Explain with reason the best process to produce crank shaft. You need to list and explain the stages as required by the process.

(6 marks)

14) Why the selecting of sand for molds is important at the initial stage of casting?(2 marks)

15) In sand casting, generally, further operations are required after the cast part has solidified and removed from the mould. Discuss at least three of those required operations.

(3 marks)

16) Give a step-by-step procedure for Investment. casting and list two common products that can be made using Investment casting.

(5 marks)

17) Casting is a process where molten metal flows into a mould and solidifies in the shape of the mould cavity.

i) Identify four (4) important factors affecting the selection of a casting process. (2 marks)

ii) Investment casting is an old casting technique where an expendable mould is coatedwith a refractory material to form the casting mould.Describe the characteristics of the products produced from investment casting. (2 marks)

iv) Specify the advantages and disadvantages of the precision investment casting process over other casting processes.

(4 marks)

18) A variety of defects may result in cast parts due to many reasons. Briefly explainfour (4) common casting defects in the cast parts.

(2 marks)

19) Determine the factors that influence the fluidity of a molten metal during pouring into a mould cavity? Why should turbulent flow of the molten metal into the mould be avoided?

C02/C3 (5 marks)

20) Contrast the process flow of vacuum casting and pressure casting in permanent die casting process.

C03/C6 (4 marks)

21) Sketch and describe the process sequences and the applications of sand casting.C01/C2 (6 marks)

22) Write four (4) indicators which are used to determine the quality of the sand mold.(5 marks)

23) Contrast the benefits between lost foam casting and other types of casting.

(4marks)24) Sketch and describe the process sequences and the applications of shell molding.

(6 marks)

(4 marks)