ENB231-T1-S1-2007

ENB231-T1-S1-2007 - GUT Student Number Surname Given Name/s...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: GUT Student Number Surname Given Name/s Examination Paper SEMESTER: FIRST SEMESTER EXAMINATIONS 2007 UNIT: ENBZBI MATERIALS AND MANUFACTURING 1 - THEORY 1 DURATION OF EXAMINATION: PERUSAL: 10 MINUTES WORKING: 2 HOURS EXAMINATION MATERIAL SUPPLIED BY THE UNIVERSITY: EXAMINATION BOOKLETS - TWO (2) PER STUDENT CRITERIA SHEET - TWO (2) PAGES ATTACHED EXAMINATION MATERIAL SUPPLIED BY THE STUDENT: WRITING IMPLEMENTS CALCULATORS - ANY TYPE INSTRUCTIONS TO STUDENTS: Students are prohibited from having mobile phones or any other device capable of communicating information (either verbal or written) in their possession during the examination NO NOTES MAY BE MADE DURING PERUSAL TIME SECTION A - ALL FIVE (5) QUESTIONS ARE TO BE ATTEMPTED SECTION B — ALL FIVE (5) QUESTIONS ARE TO BE ATTEMPTED PLEASE ENSURE YOUR NAME AND STUDENT NUMBER ARE INSERTED ON THE CRITERIA SHEET ATTEMPT EACH SECTION IN A SEPARATE EXAMINATION BOOKLET ALL QUESTIONS ARE OF EQUAL VALUE Queensland University of Technology Gardens Point GUT Kelvin Grove GUT Carseldine GUT Caboolture 1 All Questions are to be Attempted (50%) All Questions have Equal Marks Use a Separate Answer Book for each Section SECTION A (MATERILAS REALTED QUESTIONS) QUESTION 1 Solidification and Microstructures (a) How can rapid solidification of metals be achieved? What are some of the effects of rapid solidification on the microstructure of metallic materials? (a) Briefly describe the specimen preparations needed in order to examine the microstructure of your metallic samples using optical microscope. QUESTION 2 Heat Treatments and Phase Diagrams (a) A slowly cooled hypoeutectoid steel shows a microstructure containing 50% pearlite and 50% ferrite. Using the Fe-C phase diagram, estimate the carbon content in this alloy. (Show details of how you arrive at your answer) (b) How do austenite stabilising elements and ferrite stabilising elements affect the heat treatment of steels? Indicate the effects of these types of alloying elements on features such as the eutectiod point in the Fe-C phase diagram. QUESTION 3 Cast Iron (a) Describe the formation of white cast iron and malleable cast iron. Give examples of the uses of the two different types of cast irons. (b) Identify the type of cast irons for the microstructures in Figure 1. How do the different structures occur and briefly explain their mechanical properties. Figure 1 Microstructures of two different Cast Irons. QUESTION 4 Surface Hardening What are the differences between carbiding and nitriding? In your answer include a description of each process, the requirements for the steel used in each process and ' where each process is generally applicable. ENB231T1.071 .../cont QUESTION 5 Hardenability of Steels The data in Figure 2 and Figure 3 are obtained from J ominy end quench for a long round steel bars using different cooling medium and conditions. (a) A component with a diameter of 100 mm must be quenched in agitated oil (H=O.5). If the component must have a hardness of at least 40 HRC explain which steel or steels should you choose. (b) If quenched in still water (H=l), determine the maximum size of bar of 1345 steel that will have a hardness in excess of 45 HRC at the centre. Relation between centre of a bar and the position along the Jominy bar. 180 170 160 150 140 ~ 130 - _n N O _n .5 O A O O Bar diameter (mm) (D O Distance from quenched end (mm) Figure 2 Graph relating Jominy end quench distance to equivalent bar diameter. Jominy End Quench Data for Three Steels. «w AISI 1045, AlSI 1345, ----- AISI4145 Hardness, HRC. NS! 1345 AISI 1045 0 5 10 15 20 25 30 35 4O 45 50 Distance from quenched end, mm. Figure 3 Representative Jominy end quench data for three steels. ENB231T1.071 .../cont 3 SECTION B (MAUFUCTURING REALTED QUESTIONS) QUESTION 6 Casting In casting experiments performed using a certain alloy and type of sand mold, it took 155 sec for a cube-shaped casting to solidify. The cube was 50 mm on a side. 2 (a) Determine the value of the mold constant in Chvorinov's Rule: if = 0(1) . A (b) If the same alloy and mold type were used, find the total solidification time for a cylindrical casting of diameter 30 mm and length 50 mm. QUESTION 7 Extrusion of Metals (a) Explain the different ways in which changing the die angle affects the extrusion process. (b) Assuming an ideal drawing process, what is the small diameter to which a 100 mm diameter rod can be drawn? (c) Briefly comment on the grain flow patterns in the extrusion process with respect to dead metal zone and the possible defects the phenomenon can induce in an extruded part. QUESTION 8 Sheet Metal Forming (a) What is springback in sheet metal bending? (b) The foreman in the pressworking section comes to you with the problem of a blanking operation that is producing parts with excessive burrs. (i) What are the possible reasons for the burrs, and (ii) what can be done to correct the condition? QUESTION 9 Welding (a) What are the factors that affect weldability? (b) Under what circumstances would brazing or soldering be preferred over welding? QUESTION 10 Forming of Plastics What are some of the general considerations that product designers must keep in mind when designing components out of plastics? END OF PAPER ENB231Tl.071 (i) 2000 69.0 0:220 0000606 00:092 >=00too 0cm 050:3 0E00 9:me 0:0 “2900* Em>0_00 0:0 :6:an 0E .6 0E8 00:0: I “00:00 >309: 000 “05 mcozmcmfixm 020:0 mc0_=::00 .mcozatowwn 0:200:00? 9.6390 0000506 00__0o_0_ >=00too 0:0 >200? 050230 @5me 0:0 M00200», 00050.2 000 Emtoafi :0 950: I 08:05.30 090:0 0003020000 0860:0020 50:99: .wcoEczflo “00:00 050390 I 02:20.06 00:00.2 >200too 0:0 0.0950 05me 0:0 “009.00% E929 0:0 Emtoch 05 6 00E 8%: l “00:00 >=00E 000 005 000200033 8%:0 0co:_c:0_o 0025:0000 0:200:36 36:00 050305 I 0:20.006 00:09“: 0E00 9:me 0:0 "000509, Emtoars 2:0 :2 9:2 I “00:00 >280 000 “0r: 0:020:90? 020:0 0:0:_::00 0:020:00wa 0:200:86 0E00 96390 0:20.506 09.00 0me 0:0 390$ 30* 0 #0: t 20:90:. 9:00:65 5000 0008 50:00 00390 I act-50035:. 0:0 m_m_._0umE v.0 asap—50.00:: 0:0 030.265. 80:39:00 “>0 0000.265. 0>_wc0:0aE00 000000002000 30> . a m “>0 0m00§0cx 0005 000:0:0E00 30> . “>0 0902305 08:000E00 30> . “>0 000036,; 0.000 90:08:00.0 30> . E 030500 3 05:30 0 222.30 0 93230 .0. 232.30 "0:50:05 0.00:0: £00.03... E0035 3:05 0.00005 ‘ "0:002 E0035 333 mem .05“. F mczomcacm 0 23.322 Smmzm 0E: 000:5: E0030 0:0 0E0: 50> 3098 30am. 0.23.20 0:: :0 0:25 #:00 0000.0 "whOz ENB231T1.071 EEO: :000m 0.5::0 0:02 002 0E 0::: 0.00:.20 0:0 50:00:. 0:0 002 >0E 0:0 >.:00:00 0::: 0.0250 0:5 0::: 0.0050 05.550 0:.:.200: 05.5.00 0:: :0 :0: ::.>> >_:00:00 05.5.00 0.00:.20 0:2: >_:00:00 ::.>> 2:00:00 :0 >:.5.:0E 0:: I >.0:0::xo500 20.20.00 I 0:50 20.20.00 I 05.5.00 50:: 20.20.00 I 05.5.00 20.20.00 I 05.5.00 0:: :0 0>.:0 20> 30: 05.5.00 0:: :0 05.5.00 30:0 0: 0:0.:0.20.00 0>..:0 20> :50: 30:0 0:: :0 0>.:0 20> :50: 50> :. 000:0 5000000: 0: 0500.20.00 50> 0:0 0500.20.00 0:0.:0.20.00 25:0 0: 0:0.:0.20.00 0:: :20 :00 >.:00.0 :_ 000:0 >:000000: :50: 0 E5000 I 50> :. 000:0 :20 :00 I 50> :. 000:0 :20 :00 I .000 :09: 0:: :2 0:: ._0 :20 :00 >.._00.0 I 02550500.: 0:0 0.00808 “0: 00.252 “0:0 :0 0:5305 .0 0002 0>0: >0E 20> . “0:0 00.205: 00: 20> . “0:0 00.2E5: 002 20> . “0:0 00.2E5: 002 20> . 00.2E5: 002 20> . .00.:0E2: 020m >.:00:50 >:...000..000 >:...000..000 :00: 50:00 >.:00E 0:0 :0:: 00.55 0:0 00.>05 >.:00:00 >:...000..000 50:50:. >.:00E :0:: >:...000..000 :0:: 50:50 >.::0:.Eo005 0:0 0:000:00 0:: :0:: 00.>05 0: 0:0 :00: >:...000..000 :00: 00.>o5 0:0 0:000:00 0:0 :0.:>> 0:000:00 00.5000 >.:00:00 0.00 :000 :0: 0>0: I 0:0 0:000:00 :.0.0x0 I 0:: :0 0:50 :.0.0x0 I 0:: 00.5000 >.00.0:00 I 0:0 >.:0205:: I 50052:. 0:0 :0.:0E5::. 0:0 0:00 0:: 00>.0:0 >.:00:50:. :o.:0::2:. 0:00 :0>.0 0:: ..0 0:0 55:05. 0: 50052:. 0:0 0:00 .:0.:0E5::. 0:0 0:00 0:0 0:00 0:: :0 55:05. >.0:05000 0.00 :000 :0: 0>0: I 0:::0 50:: 55:05. I 025 0:50 55:05. I :09: 55:05. >.0:05000 I 0:0 >.:00.0 I “0:0 OX0: :. “0:0 5 0000E. 5 0:005 “0:0 3x0: “0:0 9x0: :. 3x0: :. 5 0000:: 055503000: 5 00.00: :. 0.0V :. 5 0000:: 5 0:005 5 5 0000:: 5 0:005 5 “0:0 3x0: :. 5 0000E. 5 5 0:005 5 00.00: 0:0 0.0.558 00::0005 :o.:0::2:. 00.00: :. .00: 0050005 00.00: :. .00: 00::0005 0:005 5 00.00: :. .00: :. .00: 00::0005 :0 cos—0.50:0: 0:0 0:00 0:: :00500 50052:. 0:0 0:00 0:: 5.5505. 0:0 00::0005 :0.:0E:2:. :0.:0E5::. 0:0 0:0 0:00 00>.0:0 0::: 0000. 00.05 20> . 00>.0:0 0: :0E0::0 20> . 0:00 0:: 00>.0:0 20> . 0:0 0:00 0:: 00>.0:0 20> . 0:00 0:: 00>.0:0 20> . 0:0 555:0. ENB231T1.071 ...
View Full Document

This note was uploaded on 11/03/2011 for the course EN 40 taught by Professor Mcgregor during the Three '10 term at Queensland Tech.

Page1 / 6

ENB231-T1-S1-2007 - GUT Student Number Surname Given Name/s...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online