Material Properties - Material Science and Engineering - Old Exam Paper, Exams of Materials science

Download Material Properties - Material Science and Engineering - Old Exam Paper and more Exams Materials science in PDF only on Docsity! - 1 - CORK INSTITUTE OF TECHNOLOGY INSTITIÚID TEICNEOLAÍOCHTA CHORCAÍ Semester 2 Examinations 2011/12 Repeat Module Title: Material Science & Engineering Module Code: MECH6012 School: Mechanical & Process Engineering Programme Title: Bachelor of Engineering (Honours) in Mechanical Engineering – Year 1 Bachelor of Engineering (Honours) in Biomedical Engineering – Year 1 Programme Code: EMECH_8_Y1 EBIOM_8_Y1 EOMNI_8_Y1 ECPEN_8_Y2 External Examiner(s): Mr J.J. Hayes, Prof. S. Leen, Mr G. Clerkin, Dr L. McNamara Internal Examiner(s): Dr Gerard Kelly Instructions: Answer any three questions. All questions carry equal marks. Duration: 2 hours Sitting: Autumn 2012 Requirements for this examination: Note to Candidates: Please check the Programme Title and the Module Title to ensure that you have received the correct examination paper. If in doubt please contact an Invigilator. - 2 - Q1. (a) Ceramics are intrinsically stronger than metals. However their use as an engineering material is limited. Identify 4 properties of ceramics which make them useful in an engineering context and outline how their properties are influenced by their atomic bonding arrangements. Suggest why they are they poor conductors. (6 marks) (b) Some classes of materials exhibit directionality in their properties. Identify which classes of engineering materials and explain why. (5 marks) (c) Briefly describe the relationship between bond energy and material properties such as Elastic modulus, Coefficient of Thermal Expansion (CTE) and Melting Temperature (TM). (5 marks) (d) Identify 3 principle metal crystalline structures giving one example of each type. (6 marks) (e) Explain why we study material “defects” in engineering. Identify 3 types of “defects” commonly found in metals and explain the significance of one of these. Identify a situation where “defects” may be beneficial to a material’s properties (6 marks) (f) Explain what happens when a ductile material is subject to an externally applied force in a given direction. Why are fine grained materials less ductile than large grained materials? (5 marks) Q2. (a) Briefly describe a method for the determination of the strength of ceramic materials. How can it be improved? Why are conventional tensile tests not usually employed to characterise the strength of Ceramics? (10 marks) (b) A 3 point bending test is conducted on a cylindrical specimen of aluminium oxide having a reported flexural strength of 300 MPa. If the specimen radius is 5.0mm, and the support point separation distance is 15.0mm, predict whether or not you would expect the specimen to fracture when a load of 7500 N is applied. Justify your prediction. (18 marks) (c) Would you be 100% certain of the prediction in part (b). Justify your answer. (5 marks)