The primary aim of this course is to give students basic knowledge of materials, microstructure and processing technologies of interest for automotive and mechanical engineering. The properties of the main classes of materials will be presented, in particular their mechanical and thermal properties. Special attention will be given to steels, cast irons and Al alloys along with their manufacturing processes. Applications of selected classes of steels, Al alloys, cast irons will be discussed, together with the main classes of polymers, aiming to guide students toward material selection, design and quality assessment.
The integral STM/TMM course provides the basics of metallic and non-metallic materials science along with the most common processing technologies. A fundamental goal of the course is the knowledge of the relationships between chemical composition, microstructure, material properties and processing parameters. An important engineering outcome of the STM-TMM course is the understanding of the criteria for material selection, product design and quality assessment. Along with the materials science that lies behind, some specific case studies will be presented to allow the student to understand how properties can affect materials selection and processing. Thus, science-led and design-led approaches to materials teaching will be synergistically combined to offer the information that will be needed to achieve a deep knowledge and to enable successful materials selection. Microstructural aspects, mechanical and thermal properties and a focus on non-metallic materials such as ceramics, glasses, polymers and composites are subjects of the STM course. More in-depth understanding and applications of metals and alloys along with manufacturing technologies are presented in the subsequent TMM course.
The main aim is to provide the student with a robust background in materials, able to couple scientific and technological knowledge in a synergistic manner, providing general guidelines for translating scientific knowledge into technological tools for mechanical and automotive engineering.
The student will learn:
- the relation between materials atomic structure and properties;
- how to exploit this scientific background in controlling materials properties;
- how to select materials to fulfil design requirements;
- to develop a confident approach to materials and their properties;
- how the main mechanical tests are executed practically;
- how to correlate the mechanical and technological properties of alloys with manufacturing technologies,
- how to optimally select metals and alloys, including manufacturing processes for the design and construction of mechanical components and structures under specified operating conditions.
The primary aim of the integral STM-TMM course is to provide the student with a basic knowledge of materials science to understand the synergistic coupling between materials and technology and, finally, its engineering translation into useful guidelines to select materials and manufacturing processes of interest to mechanical and automotive engineering.
The student will learn how to:
- interlink crystal structure and materials properties;
- extract mechanical properties from laboratory test;
- understand materials properties and microstructure change during processing;
- predict the final component performances after processing to meet specifications;
- select materials and manufacturing processes upon design requirements or service conditions;
- develop an engineering approach to establish a link materials, properties, processes and performances;
The student is required to have a robust, basic knowledge of Chemistry and Physics.
The student is required to have a basic knowledge of Mathematics, Chemistry and Physics.
The course is developed along Lessons, Exercise and Lab Training.
Science and Technology of Materials (STM): Introduction on metals, polymers, basic notions on ceramics, glasses and composites.
Correlations structure/property of materials, Crystalline structure and defects, Amorphous structure, Plastic deformation. (10 hours). Mechanical and thermal properties, their relation to materials structure (20 hours). Phase diagrams use and examples (10 hours). Polymers, glasses: properties, uses and related technologies (10 hours).
Technology of Metallic Materials (TMM). Brief review of metallic bonding theory: electronegativity, anisotropy and allotropy, Humé-Rothery rules; solid solutions, intermetallic and interstitial compounds. Extended treatment of lattice defects in metals. Multiscale of microstructure; inspection and diagnostics by microscopy. Strengthening mechanisms. Corrosion of metals and alloys and their protection methods. Tensile test; the Ludwik-Hollomon law; extraction of formability parameters from tensile test curve. (20h).
Manufacturing of alloys. Manufacturing by casting technologies, Homogeneous/ heterogeneous nucleation and phase growth upon solidification; casting microstructure and defects, semi-solid casting; solid-state phase transformations. Manufacturing by plastic deformation (hot, warm and cold forming); stress relieve, recrystallization, grain growth; superplastic forming; forging, rolling, extrusion. Cold sheet forming: deep drawing, hydroforming; influence of processing methods on microstructure and mechanical properties. Sheet formability tests; FLD curves. Manufacturing by powder metallurgy. Overview of welding, alloys weldability, welding defects. (10h)
Ferrous alloys: European nomenclature; basic phase diagrams: metastable Fe-Fe3C, Fe-N, Fe-Ni, Fe-Cr; production of steels; influence of alloying elements; equilibrium and non equilibrium phases in steels; their microstructure and distinctive properties. TTT curves and CCT curves: origin, interpretation and their application to heat treatment of steels. Annealing, normalizing, quenching and tempering. Hardenability and Jominy test; thermomechanical heat treatments: austempering and martempering. Embrittlement and residual stresses upon cooling. Surface hardening of steels: induction and laser hardening, carburizing, nitriding and carbonitriding treatments. Stainless steels. Example of selection of steels for mechanical applications. Cast irons: European nomenclature of cast irons; equilibrium Fe-C phase diagram, microstructure and mechanical properties of grey, ductile, white cast irons; heat treatment method and mechanical properties. (15h)
Non ferrous metals: alluminum and alluminum alloys; European nomenclature, classification. Casting alloys: influence of alloying elements; Al-Si phase diagrams. Methods of microstructure refinement. Wrought alloys. Strengthening by heat treratment: aging, underaging and overaging. Mechanical properties. Selection criteria of alloys for mechanical applications.
Overview of magnesium and magnesium alloys; titanium and titanium alloys; copper and its alloys.
The STM course includes theoretical lectures (35 h) and exercises (15 h).
The main topics of the STM course are:
- General introduction to engineering materials (metals, ceramics, glasses, polymers, composites);
- The basic structure-property relationship of materials;
- Crystalline and amorphous structure;
- Lattice defects in solid materials;
- Mechanical properties (elastic and plastic behaviour) and their relation to crystal structure;
- Thermal properties and their relation to crystal structure;
- Phase diagrams: theory, practical examples, and applications;
- Focus on non-metallic materials (ceramics, glasses, polymers, composites): properties, uses and related processing technologies.
STM: numerical exercises and/or open questions on phase diagrams, on mechanical and thermal properties of materials.
TMM. In laboratory: tensile, hardness and impact tests. Metallography: preparation of samples and observation with optical microscope. Exercise classes: the topics of practical relevance will be explored as case studies through exercise. 30 min videos on steel production and on the relationship between microstructure and mechanical properties will be shown for better insight. The Program CES-EDUPACK will be introduced and exploited to solve a few mechanical applications.
In addition to theoretical lectures (35 h), practical and training exercises are run in parallel about crystallography, phase diagrams, mechanical and thermal properties of materials (15 h).
The teaching material will be available in the form of slides (STM) lecture notes
In addition, the following textbooks are suggested as guideline as well as for in-depth study.
W. D. Callister "Materials Science and Engineering An Introduction" – John Wiley & Sons, Inc.
• Structure and Properties of Engineering Alloys, W.F. Smith, McGrawHill, 2^ Ed., 2004.
• R.A. Higgins - Materials for engineers and technicians: applied physical metallurgy, 6th ed., Arnold, 2006.
• M. Ashby – Materials Engineering Science Processing and Design, BH, 1st Ed., 2007.
• Meyers-Chawla - Mechanical Behavior of Materials, 2nd ed., Cambridge, 2009.
• Z. Marchiniak, J.L. Duncan, S.J. Hu, Mechanics of Sheet Metal Forming, BH, 2nd Ed., 2002.
• M.F. Ashby, D.R.H. Jones, Engineering Materials 1: An introduction to properties, applications. and design, B/H ed., 2012.
Learning is mainly based on lecture slides provided by Professors and uploaded prior to the class on the course webpage, as well as on the students’ own notes. In addition, the following textbook is suggested for an in-depth study:
W. D. Callister "Materials Science and Engineering An Introduction" – John Wiley & Sons, Inc.
Modalità di esame: Prova scritta (in aula);
Exam: Written test;
Students who pass either TMM or STM exam, are able to hold their score, until the other exam is passed, for a maximum time limit of one academic year. Only when both exams passed, the final mark, which results from the algebraic average of both exam marks, will be formally recorded on the student’s electronic "libretto". 18/30 is the minimum to pass each exam. 30/30 cum laude (L) is the maximum. Cum laude (L) is awarded to exceptionally good exams, exceeding the maximum, as a discretional decision of the evaluator.
The STM the exam consists in a written test based on four questions and/or exercises similar to those done during STM lectures and covering all the STM program; it will last one hour, the end time will be written on the blackboard; use of internet, books and notes is not allowed, as well as any communication with other students, which will result with the end of the exam. It is possible to leave the room during the exam, but this means the exam cannot be continued. Exceptions due to proven health issues are allowed. Students are allowed to use their calculator. An identity card with picture must be kept on the desk during the exam, together with pens, ruler and calculator. The students are requested to write in an understandable way, not with pencils; no additional pages must be added to the provided ones. Bags and backpacks must be left at the room exit. Students willing to withdraw must write "withdrawn" on the first page, give the exam text back to the teacher, then exit the room. Results will be communicated on the course web page by the end of the exams’ session; students can see their revised exam: date and place will be communicated on the course web page.
The TMM exam consists of two steps: a written test (three "semi-open" questions to be answered within 30 min) and an oral test (two questions for 10-15 min). The first step aims at assessing the acquired fundamentals of TMM. The oral test will start with an initial question, which may relate with the written test whereas the second question may require the solution of a case study, especially on applications of materials selection. "Semi-open" means that the questions will imply answers within a fixed number of and specific guidelines.
Gli studenti e le studentesse con disabilità o con Disturbi Specifici di Apprendimento (DSA), oltre alla segnalazione tramite procedura informatizzata, sono invitati a comunicare anche direttamente al/la docente titolare dell'insegnamento, con un preavviso non inferiore ad una settimana dall'avvio della sessione d'esame, gli strumenti compensativi concordati con l'Unità Special Needs, al fine di permettere al/la docente la declinazione più idonea in riferimento alla specifica tipologia di esame.
Exam: Written test;
Consistently with the expected general learning outcomes, the STM exam aims at verifying the students’ learning of the theoretical and practical topics taught in the lectures and training classes, including their capability of reading and using phase diagrams, and solving numerical exercises on mechanical and thermal properties of materials.
An identity card with clear picture together with the PoliTO I.D. card must be shown to the Professors prior to entering the exam room.
The STM exam consists of a written test based on around 12-15 questions including open questions, multiple-choice questions and numerical exercises (similar to those solved during STM training classes), covering the overall STM program.
The STM exam lasts around one hour. Students cannot leave the room during the exam, except for proven health conditions or if they want to withdraw. In both cases, students must return the exam paper back to the Professor before leaving the room. Students willing to withdraw must write "withdrawn" on the first page, give the exam text back to the Professor, and then definitely exit the room.
The use of internet, books and notes is forbidden, nor any verbal or electronic communication between students is allowed otherwise resulting in a failure of the exam. Students are only allowed to use their own calculator, pens and ruler; blank paper sheets for the exam are provided onsite by the teaching staff.
The written test must be readable, written with pen (not pencils); no additional pages must be added to the regular ones.
Personal bags and backpacks must be placed along the walls of the exam classroom.
Results are notified on the STM course webpage by the end of the exam session.
IMPORTANT NOTE: students passing either STM or TMM exam may hold their mark until the other exam is passed; there is no time limit for STM, while there is a maximum time limit of one academic year for TMM. After passing both exams, the final mark of STM/TMM is registered on the student’s electronic booklet ("libretto") as an algebraically averaged mark from both exam marks rounded by defect. The score of 18/30 is the minimum threshold mark to pass each exam whereas 30/30 cum laude (30L) is the maximum one. The laude (L) may be awarded to top ranking students, who exceed or even exceed the maximum score of 30 in both exams, and always upon discretional decision of the evaluators.
In addition to the message sent by the online system, students with disabilities or Specific Learning Disorders (SLD) are invited to directly inform the professor in charge of the course about the special arrangements for the exam that have been agreed with the Special Needs Unit. The professor has to be informed at least one week before the beginning of the examination session in order to provide students with the most suitable arrangements for each specific type of exam.