1.Name the three basic category of materials.

Metals ,ceramics and polymers 2.What are the four categories of shaping process? Give an example for each category with aid of sketches.

Solidification processes: - starting material is a heated liquid or semifluid

Examples: metal casting, plastic molding

Particulate processing :- starting material consists of powders

Deformation processes - starting material is a ductile solid (commonly metal)

Example:- (a) forging, (b) extrusion

4. Material removal processes - starting material is a ductile or brittle solid

Examples: machining such as turning, drilling, and milling; also grinding and

nontraditional processes

3.Ferrous metals include which of the following;

(a) Aluminum, (b) Cast Iron, (c) Copper, (d) Gold and (e) Steel? 5.Which of the following engineering materials is defined as a compound containing metallic and non-metallic elements: (a) ceramic, (b) composite, (c) metal, or (d) polymer

6.Which of the following process start with a material that is in a fluid or semi-fluid state and solidifies the material in a cavity (two best answers) : (a) casting, (b) forging, (c) machining, (d) molding, (e) pressing, and (f) turning?

7.Particulate processing of metals and ceramics includes which of the following steps (two best answers): (a) adhesive bonding, (b) deformation, (c) forming, (d) material removal, (e) melting, (f) pressing, and (g) sintering?

8.Deformation processes include which of the following (two correct answers): (a) casting, (b) milling, (c) extrusion, (d) forging, (e) milling, (f) painting, and (g) sintering?

9.Which of the following is a machine used to perform extrusion: (a) forge hammer, (b) milling machine, (c) rolling mill, (d) press, (e) torch? 10.What is the dilemma between design and manufacturing in terms of mechanical

properties?

Dilemma: mechanical properties desirable to the designer, such as high strength, usually make manufacturing more difficult. 11.What are the three types of static stresses to which materials are subjected?

Tensile - tend to stretch the material

Compressive - tend to squeeze it

Shear - tend to cause adjacent portions of material to slide against each other

12.State Hook’s law.

Hooke's Law: stress= E e where E = modulus of elasticity

e is the strain

13.What is the difference between engineering stress and true stress in a tensile test? Engineering Stress = F/Ao

F = applied force, and Ao = original area of test specimen

True stress = F/ A

F = force; and A = actual (instantaneous) area resisting the load.

14.What is hardness?

Resistance to permanent indentation

Good hardness generally means material is resistant to scratching and wear

15.Which of the following are the three basic types of static stresses to which a material can be subjected (three correct answers): (a) compression, (b) hardness, (c) reduction in area, (d) shear, € tensile, (f) true stress, and (g) yield?

16.If stress values were measured during a tensile test, which of the following would have the higher value: (a) engineering stress, or (b) true stress?

17.Which one of the following types of stress-strain relationship best describes the behaviour of brittle material such as ceramics: (elastic and perfectly plastic, b) elastic and strain hardening, (c) perfectly elastic, or (d) none of the above? 18.Most hardness tests involve pressing a hard object into the surface of a test specimen and measuring the indentation that results: (a) true, or (b) false?

19.Viscosity can be defined as the ease with which a fluid flows: (a) true, or (b) false?

20.Define the density as a material property.

Density = weight per unit volume

21.Explain with aid of sketches the difference between melting characteristics between a pure metal element and an alloy. Temp alloy temp pure

Time Time

22.In heating of most metal alloys, melting begins at a certain temperature and concludes at a higher temperature. In these cases, which of the following temperatures marks the beginning of the melting: (a) liquidus , or (b) solidus?

23.What is the effect of the temperature on the mechanical properties such as; strength,

hardness and ductility?

Strength and hardness decrease and ductility increase ductility

temp

24. What are the major two groups of metal?

Ferrous and non ferrous.

25. What is the range of carbon percentages which defines an iron-carbon alloy as steel?

0.2 2.1 % carbon if it increase it will be cast iron.

26. What is the effect of the carbon percentage on the mechanical properties of steel?

Strength and hardness increase and ductility decrease ductility

27. Which of the following properties or characteristics are inconsistent with the metals (

two correct answers): (a) good thermal conductivity, (b) high strength, (c) high electrical

resistivity , (d) high stiffness, or € ionic bonding?

28. Which of the following alloying elements are most commonly associated with stainless

steel (two best answers): (a) chromium, (b) manganese, (c) molybdenum, (d) nickel, and (e)

tungsten?

29. By the aid of schematic drawing, show the basic elements of the sand casting mold.

30. What are the three types of heats that are associated with heating the metal to molten

temperature sufficient for casting?

1. Heat to raise temperature to melting point

2. Heat of fusion to convert from solid to liquid

3. Heat to raise molten metal

31. Explain the Chvorinov's Rule.

TST = Cm (V/A)n

where TST = total solidification time; V = volume of the casting; A = surface area of

casting; n = exponent with typical value = 2 and Cm is mold constant.

32. What is the riser?

Reservoir in the mold which is a source of liquid metal to compensate for shrinkage of the

part during solidification.

33. Explain with aid of sketches shrinkage in casting.

34. A casting with a higher volume-to-surface area ratio cools and solidifies more (a) quickly, or (b) slowly than one with a lower ratio. 35. Patternmakers account for solidification shrinkage and thermal contraction by making mold cavity size (a) bigger, (b) smaller than that of the final product. 36. The riser must be designed to freeze (a) before, (b) after the main casting in order to

satisfy its function.

37. What is the function of the core in mold?

The mold cavity provides the external surfaces of the cast part .

In addition, a casting may have internal surfaces, determined by a core, placed inside the

mold cavity to define the interior geometry of part.

38. Compare between cold and hot forming in terms of; definition, advantages and

disadvantages.

Cold Working: - Performed at room temperature or slightly above.

Advantage: - Better accuracy, closer tolerances

Better surface finish

Strain hardening increases strength and hardness

Grain flow during deformation can cause desirable directional properties in product

No heating of work required

Disadvantage:-

Higher forces and power required in the deformation operation

Surfaces of starting workpiece must be free of scale and dirt

Ductility and strain hardening limit the amount of forming that can be done

Hot Working: - Deformation at temperatures above the recrystallization temperature.

Advantage:-

Work-part shape can be significantly altered

Lower forces and power required

Metals that usually fracture in cold working can be hot formed

Strength properties of product are generally isotropic

No strengthening of part occurs from work hardening

Disadvantage:-

Lower dimensional accuracy

Higher total energy required (due to the thermal energy to heat the workpiece)

Work surface oxidation (scale), poorer surface finish

Shorter tool life

39. Define rolling with aid of sketch

Rolling is Deformation process in which work thickness is reduced by compressive forces

exerted by two opposing rolls

40. What are the two main functions of the rotating rolls?

Pull move and pressing.

41. Define with aid of sketches blanking and punching as shear metal cutting process.

Blanking - sheet metal cutting to separate piece (called a blank) from surrounding stock

Punching - similar to blanking except cut piece is scrap, called a slug

42– With aid of sketch, explain the relation between the punch diameter and the die size in shear

metal cutting.

Hole punch diameter = Dh

Hole die diameter = Dh + 2c

where c = clearance

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47- What distinguishes machining from other manufacturing processes? Generally performed after other manufacturing processes, such as casting, forging, and bar drawing.

Other processes create the general shape of the starting work part

Machining provides the final shape, dimensions, finish, and special geometric details that other processes cannot create

48-Identify some of reasons why machining is commercially and technologically important. - Variety of work materials can be machined:

Most frequently used to cut metals -Variety of part shapes and special geometric features possible, such as:

Screw threads

Accurate round holes

Very straight edges and surfaces

Good dimensional 49- Name the three most common machining processes.

Turning

Drilling

Milling 50- What are the two basic categories of cutting tools in machining? Give two example of operations that use each of the tooling types. The two categories are :- (1) single-point tools, used in operations such as turning and boring (2) multiple-edge cutting tools, used in operations such as milling and drilling

51 -Define the Machining process with aid of sketches. What are the advantages and disadvantages of this process. Cutting action involves shear deformation of work material to form a chip As chip is removed, new surface is exposed

The advantages:-

Variety of work materials can be machined

Variety of part shapes and special geometric

Good dimensional accuracy and surface finish Disadvantages:-

Wasteful of material

Time consuming

52- Define the turning process with aid of sketches. What are the applications of turning? Single point cutting tool removes material from a rotating work piece to form a cylindrical shape

The applications are :-

Facing

Chamfering

Cutoff

Threading

53- Define the drilling process with aid of sketches. What are the applications of drilling?

Creates a round hole in a work part

Compare to boring which can only enlarge an existing hole

Cutting tool called a drill or drill bit

Machine tool: drill press

54- Explain the three moods of tool failure. 1. Fracture failure

Cutting force becomes excessive and/or dynamic, leading to brittle fracture

2. Temperature failure

Cutting temperature is too high for the tool material 3. Gradual wear

Gradual wearing of the cutting tool

55- Why are the cutting temperature important in the machining process? High cutting temperatures 1. Reduce tool life 2. Produce hot chips that pose safety hazards to the machine operator 3. Can cause inaccuracies in part dimensions due to thermal expansion of work material 56-

Uses a consumable electrode consisting of a filler metal rod coated with chemicals that provide flux and shielding. 57-

A group of welding processes that use a combination of heat and pressure to accomplish coalescence.

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-Both use filler metals to permanently join metal parts, but there is no melting of base metals -When to use brazing or soldering instead of fusion welding:

Metals have poor weld-ability

Dissimilar metals are to be joined

Intense heat of welding may damage components being joined

Geometry of joint not suitable for welding

High strength is not required

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Filler metal Tm greater than 450C (840F) but less than Tm of base metal(s) to be joined.

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Joint strength is generally less than a welded joint

Joint strength is likely to be less than the base metals

High service temperatures may weaken a brazed joint

Color of brazing metal may not match color of base metal parts, a possible aesthetic disadvantage.

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Structural adhesives – of greatest interest in engineering, capable of forming strong, permanent joints between strong, rigid adherents. 64-

Applicable to a wide variety of materials

Bonding occurs over entire surface area of joint

Low temperature curing avoids damage to parts being joined

Sealing as well as bonding

Joint design is often simplified, e.g., two flat surfaces can be joined without providing special part features such as screw holes

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Compression process in which material is forced to flow through a die orifice to provide long continuous product whose cross-sectional shape is determined by the shape of the orifice

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- Polymer is heated to a highly plastic state and forced to flow under high pressure into a mold cavity where it solidifies and the molding is then removed from cavity. Typical cycle time (10 to 30 sec), but cycles of one minute or more are not uncommon. Mold may contain multiple cavities, so multiple moldings are produced each cycle.

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75- what kinds of products are produced by blow molding ? Products: disposable containers for beverages and other liquid consumer goods, large shipping drums (55 gallon) for liquids and powders, large storage tanks (2000 gallon), gasoline tanks, toys, and hulls for sail boards and small boats 76- what is the form of the starting material in thermo forming ? Flat thermoplastic sheet or film is heated and Deformed into desired shape using a mold. 77-

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80- Explain compression molding, blow molding and injection molding in terms of; definition, schematic drawings and applications. Blow Molding Molding process in which air pressure is used to inflate soft plastic into a mold cavity

Applications: Important for making one-piece hollow plastic parts with thin walls, such as bottles

Injection Molding: Polymer is heated to a highly plastic state and forced to flow under high pressure into a mold cavity where it solidifies and the molding is then removed from cavity

Applications:

Compression Molding

Applications: A widely used molding process for thermosetting plastics. _____________________________________________________________________