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QUESTION 3 What is the hypo-eutectoid formation indicated by the arrow in this carbon steel microstructure? (A) ferrite (B) pearlite (C) austenite (D) cementite
QUESTION 4 High-voltage transmission cable insulation would most likely be manufactured from (A) polyvinyl chloride. (B) polypropylene. (C) polyethylene. (D) polystyrene.
QUESTION 10 stress \ strain The key feature indicated by the arrow in this mild steel stressstrain diagram is (A) ultimate tensile stress. (B) Youngs modulus. (C) plastic limit. (D) yield stress.
QUESTION 11 (4 marks) Explain what is meant by the proportional limit of a material as indicated on a stress—strain diagram. Provide an annotated sketch to support your explanation.
QUESTION 17 (5 marks) Explain how the chemical composition of high-carbon steel contributes to two of its mechanical properties in the context of two industrial applications.
QUESTION 21 (5 marks) 2000 1800 1600 Temperature (°C) 1400 1200 () o S N S W O N O N S AN S ~ S o0 S O S ek S S Percentage metal A (%) Use and annotate the binary equilibrium diagram for an alloy of metals A and B to calculate the percentage proportion of solid and liquid material present for an alloy of 50% metal A and B at 1400 °C. Answer to the nearest whole unit.
QUESTION 1 Conventional automotive torsion bars are manufactured using steel with a carbon content of 0.3% to 0.5% which is (A) low-carbon steel. (B) high-carbon steel. (C) mild-carbon steel. (D) medium-carbon steel.
QUESTION 3 Stress Strain The stiffness of a material can be identified using which area of the stressstrain diagram? (A) J (B) K (C) L (D) M
QUESTION 8 3007 HW - = _/ 2007 2 G & i 1005 /F 0 0 20 40 60 80 Pb % Tin (Sn) Sn In the leadtin thermal equilibrium phase diagram a liquidus line is represented by the letter (A) E. (B) F. (C) G. (D) H.
QUESTION 13 (5 marks) Explain how the microstructure of a 3% carbon cast iron changes during cooling between the eutectic and eutectoid temperatures. Annotate the diagram to identify the materials approximate location and the eutectic and eutectoid temperatures to support your explanation. Ironcarbon phase 1600 1600 1400 1400 _ 1200 1200 9 g 2 1000 1000 5 : 3 = 800 800 & So. O 5 600 600 400 400 200 200 0 0 Carbon (%)
QUESTION 14 (6 marks) Explain how the tensile test for a low-carbon steel material can be used to determine the ductility of the material. Sketch and annotate a stressstrain diagram to support your explanation.
QUESTION 1 The graph shows the tensile stressstrain curves of four different materials. This content has not been published for copyright reasons. The toughest of the four materials is (A) I (B) I (C) Il (D) IV
QUESTION 2 Waste water drainage pipe is commonly manufactured using (A) nylon. (B) polypropylene. (C) polylactic acid. (D) polyvinyl chloride.
QUESTION 6 A section of an ironcarbon phase diagram is shown. 1600 1400 ~ 1200 Oo 2 1000 oO a. 5 F 800 600 400 | | | | 0 1 9 3 4 5 % C The microstructure of the phase represented by X is solid (A) cementite. (B) austenite. (C) pearlite. (D) ferrite.
QUESTION 8 High carbon steel is used in the manufacture of (A) boiler plates. (B) railway tracks. (C) punching tools. (D) engine crankshafts.
QUESTION 12 (4 marks) State four industrial applications for carbon steel with 0.15% to 0.30% carbon content. 1. 2 3. 4
QUESTION 14 (6 marks) 400 350 300 250 200 OXL Temperature (°C) 150 100 50 F 0O 10 20 30 40 50 60 70 80 90 100 Pb % Tin (Sn) Sn Use the information included in the lead—tin thermal-equilibrium phase diagram to identify each key feature. I) solidus line IT) liquidus line IIT) eutectic point IV) eutectic temperature V) maximum solubility of lead in tin VI) maximum solubility of tin in lead
QUESTION 15 (6 marks) Contrast the suitability of mild and high carbon steel for applications in the manufacture of automotive subframes that experience repeated loads and high impacts using their microstructure and three relevant mechanical properties.
QUESTION 17 (5§ marks) Nylon can be used in the manufacture of industrial gears. The stress—strain diagram indicates the effect adding epoxidised natural rubber (ENR) has on the mechanical properties of nylon. This content has not been published for copyright reasons. Interpret the data to explain how adding different percentages of ENR to nylon influences its effectiveness for gear manufacture. Include four relevant mechanical properties to support your response.
QUESTION 21 (5 marks) Determine the percentage of the liquid components for an alloy containing 65% lead at a temperature of 250° C. Annotate the lead—tin equilibrium phase diagram as part of your response. 400 350 300 O 250 S £ £ 200 o Q. £ £ 150 100 50 0 10 20 30 40 50 60 70 8 90 100 Pb % Tin (Sn) Sn
QUESTION 2 Pearlite is composed of alternating layers of (A) ferrite and austenite. (B) ferrite and cementite. (C) gamma iron and carbon. (D) cementite and gamma iron.
QUESTION 4 Plastic gears would most likely be manufactured from (A) nylon. (B) polylactic acid. (C) polyvinyl chloride. (D) acrylonitrile butadiene styrene.
QUESTION 9 Structural steel plates and sections used for fabricating machine frameworks have a carbon content of (A) 0.07% to 0.15% (B) 0.16% to 0.30% (C) 0.31% to 0.60% (D) 0.61% to 1.25%
QUESTION 10 300 3 E ‘ 2 200 ‘ < o Q. 5 = 100 . 20 40 60 80 Pb % Tin (Sn) Sn The eutectic composition of lead and tin shown in the lead—tin thermal equilibrium phase diagram above is (A) 62% tin and 38% lead. (B) 62% lead and 38% tin. (C) 82% tin and 18% lead. (D) 82% lead and 18% tin.
QUESTION 13 (5 marks) Stress 50 MPa 50% Strain Interpret the stress versus strain curve above for acrylonitrile butadiene styrene (ABS). Explain the material`s properties with reference to the diagram to justify three appropriate engineering uses for ABS.
QUESTION 14 (6 marks) Recall an engineering problem that required machines or mechanisms as part of the engineered solution. Explain how the community involved benefited from the solution and describe the types of engineering knowledge and expertise that were used during solution development. Make reference to materials forces mechanisms and community impacts.
QUESTION 16 (5 marks) Explain the meaning of the following statement: ‘The chemical composition of materials contributes to physical properties and therefore to usability for mild- medium- and high-carbon steel.” Use examples of the mechanical applications of each steel to support your explanation.
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