QUESTION 2

a) Other option metal casting.Why? ;

i. Sand is less accurate compared to metal mould which is very precise and accurate.

ii. Sand casting need a lot of time duration in manufacturing one part, while the metal mould duration can be speculated/expected.

iii. Sand casting will give a rough surface finish compared to the metal mould which would gave an extremely fine surface finish

iv. The process in metal mould is more simpler than the sand castingv. The only advantages of sand casting compared to metal mould is sand

casting require lower cos than metal mould due to expensive equipments in metal mould.

b) i. Gating system : Is the passageway that bring the molten metal into the cavity

c) i. Process used to create objects of a fixed cross-sectional profile.

ii. A material is pushed or drawn through a die of the desired cross-section.iii. Advantages

1. Its ability to create very complex cross sections2. To work materials that are brittle.

d) Centrifugal casting is a process of rotating a mold while the metal solidifies.i. True Centrifugal Casting

1. Used mainly for pipes and liners that are cast by rotating the mold about its horizontal or vertical axis

a. The metal is held against the wall of the mold by centrifugal force.b. Core is not required.

ii. Semicentrifugal Casting1. The mold is completely full of metal as it is spun about vertical axis.

a. Risers and cores may be employed.b. Normally used for parts in which the center of the casting will be

removed by machining.iii. Centrifuging

1. Several casting cavities are located around the outer portion of a mold and metal is fed to these cavities by radial gates from the center.

a. Either single or stock molds can be used.b. Mold cavities are filled under pressure.c.

e) Porosity can significantly reduce the strength and durability of castings. The surface finish is also affected by porosity.

QUESTION 4 (example question) chapter 6

QUESTION 6

a)

- butt joint/groove weld

- corner joint/fillet weld

-  Heat affected zone during welding depends on the welding method, the  technological process, the thermal conditions, and the thermal and  physical properties of the base metal.

b) Calculation on grinding part chapter 7

c) type of extrusion

d)

QUESTION 8

a. Example question

i) Chrome plating ii)Nickel Plating iii) galvanizing iv)Parkerizing

b. Electrical Discharge Machining is a process that removes metal with good dimensional control from any soft or hard metal.

i. The tool works (fluid) - mineral oil. ii. The coolant serves as a dielectric fluid to wash away

particles of eroded metal from the work piece n maintan uniform resistance

c. Die Casting vs Powder Metallurgy (example question)

P/M than Die Casting (DC) relative to dimensional precision and machining requirements.

- P/M usually has the edge on tooling costs and machine costs. - strength, wear resistance or high operating temperatures - the corrosion resistance of copper of stainless steel

QUESTION 10

a) Machines are considered automated only when they are mechanically joined for continuous automatic handling and processing.

i. Process that can be automated1. Robot

a. Reprogrammable multifunctional manipulator designed to move materials, parts or tools.

2. Flexible MFG Systems (FMS)a. Arrangements of individual workstations

machining cells, and robots under the control of a computer.

b) To prevent the disorders,ii. A sufficient interval of rest time between episodes will

reduce the risk of developing disorders of the operators. iii. The tools can be designed to avoid exposing the operator to

physical load, noise, vibration and dust.

c) i. Skill based activities1. Carried out subconsciously and automatically very

skilful operatorsii. Rule-Based Activities

1. Carried out by operator after he recalls the rules of controlling the machine. These rules are learned thorough training and by experience.

iii. Knowledge-based activities1. Based on problem-solving and planning (no rules).

Operators rely on their knowledge about the goals to be achieved by the machine or MFG system.