Heat Treatment and Mechanical Treatment
Objectives
The main objective is to cover the more relevant technological features in the field of the heat treatment, providing an adequate comprehension of the structural changes that are induced and their influence on the mecanical behavior.
It is aimed to provide:
- mastering of the more adequate techniques for the intended structural changes,
- comprehension of the influence of the final structure of the material on its in service ehavior, namely for its echanical behavior.
General characterization
Code
7490
Credits
6.0
Responsible teacher
Rui Jorge Cordeiro Silva
Hours
Weekly - 5
Total - 84
Teaching language
Português
Prerequisites
Basic knowledge on the following areas requested:
- physical metallurgy,
- mechanical behavior,
- structural characterization techniques (metallography, X-ray diffraction, thermal analysis).
Bibliography
Textos de apoio à disciplina de Tratamentos Térmicos e Mecânicos, de F. M. Braz Fernandes.
Principles of the Heat Treatment of Plain Carbon and Low Alloy Steels, C. R. Brooks, ASM International, Ohio, 1996.
Steels. Microstructure and Properties, R. W. K. Honeycombe, Edward Arnold, London, 1981. Esta obra foi traduzida para português por M. A. Fortes e A. Ferro e publicada pela Gulbenkian.
Curso de Tratamentos Térmicos dos Aços (2 volumes), Editores: A. V. de Seabra, A. P. Loureiro; Ordem dos Engenheiros, Lisboa, 1981.
Principles of Heat Treatment, M. A. Grossman, 3.ª edição, ASM, Cleveland, 1962.
Heat Treatment, Structure and Properties of Nonferrous Alloys, C. R. Brooks, ASM, Ohio, 1984.
Techniques de l''''''''''''''''Ingénieur.
Teaching method
Duration of the sessions:
The theoretical sessions are grouped in blocks of two, with a total duration of 1 h 50 min.
The practical sessions are 3 h duration, once a week for each 16 students shift.
Theoretical lectures will be made of an oral explanation. Several points of the programme will be complemented by short demonstration experiments or computer simulations to illustrate the subject.
In the cases where it will be more notorious the need for the theoretical background corresponding to previous disciplines, there could be a preliminary presentation (by students) at the beginning of the session.
Practical sessions will be made up of 16 students shifts. Within each shift , working groups of 3 students will be constituted.
The 14 practical sesions will be devoted to the following topics:
- performance of thermal and mechanical treatments,
- ananlysis and interpretation of the results,
- mechanical properties evaluation,
- analysis of the phase transformations,
- structural characterization (SEM, XRD),
- construction of prototypes of applications of metallic alloys.
Evaluation method
Criteria
Continuous evaluation is based on the following aspects:
- the "frequency" to the students that attend the teoretical lectures and the practical sessions and have two practical reports approved; the reports are subject to an oral discussion;
- during the semester, two written tests are scheduled.
According to the results obtained, different situations will appear:
- admission to final examination as a result of the "freqiuency" awarded,
- the final examination may be skipped if the average of the quizes is greater than 9.5, in case the first written test has had a ranking above 7.5.
The final ranking will result from the weighted average (25%) of pratical sessions reports and
- the written tests average (75%) or the final examination (75%).
The ratings obtained in the assessment system at a distance equal to or greater than 15 values can be subjected to a subsequent oral test.
Subject matter
Ferrous alloys. Steels. TTT diagrams: isothermal transformation; continuous cooling transformation. Hardenability. Jominy and Grossman tests. Quenching severity. Effect of alloying elements. Heat treatments: annealing; quenching; tempering. Heat treatment of stainless steels. Sensitivation. Homogenization / solution annealing. Residual stresses: origin; consequences; mechanical working; shot peening. Thermomechanical treatments. Thermochemical treatments. Carburising. Nitriding. Carbonitriding.
Cast iron. Classes of cast iron. Characteristics. Applications. Stabilizing. Annealing. Isothermal quenching.
Light alloys. Aluminium alloys. Precipitation hardening. Alloy classification according to processing and chemical composition. Characteristics. Applications. Ti alloys. Effect of alloying elements. Single phase alloys (α or β). Two phase alloys (α or β). Annealing. Precipitation hardening. Characteristics. Applications.
Copper alloys. Bronzes. Brasses. Annealing. Precipitation hardening alloys. Other treatments. Characteristics. Applications.
Nickel super-alloys. g and g’ solid solution annealing. g / g’ misfit. Cobalt super-alloys. Characteristics.
Shape memory alloys. Crystallographic and thermodynamic principles of shape memory alloys. One-way shape memory effect. Two-way shape memory effect. Superelasticity. Classes of shape memory alloys specific treatments. Applications.
Surface treatments using high energy beams. Laser surface hardening hardening. Energy absorption. Heat transfer. Quenching. Shock hardening. General characteristics of the equipment. Applications.