Physical Metallurgy and Metallography

General characterization

Prerequisites

Basic knowledge of chemistry (chemical reactions and chemical equilibrium), chemical thermodynamics (thermodynamic functions and variables) and crystallography (crystalline systems, Bravais lattices and crystalline defects). 

Bibliography

• "Notas para apoio à disciplina de Metalurgia Física e Metalografia"; Rui Silva, FCT-UNL.
• "Phase Transformations in Metals and Alloys", David A. Porter e K. E. Easterling, Van Nostrand Reihold (UK).
• "Princípios de Ciência e Engenharia dos Materiais", Willian F. Smith, Mc-Graw-Hill de Portugal.
• "Introdução à Metalurgia", Alan H. Cotrell, Ed. Gulbenkian.

       Course documents are avaliable in Moodle plataform: http://moodle.fct.unl.pt/

Teaching method

• The discipline has weekly theoretical lessons, theoretical-practical lessons or laboratories.
• Transparencies or PowerPoint presentation is used for theoretical classes being the matter exposed in a class room when required.
• The resolution of exercises is done during the theoretical-practical lessons in class room about the matter given during the theoretical classes. Laboratorial classes are related to the experiences demonstration of the concepts already given both in theoretical and problem sessions.

Evaluation method

• The student''''''''s progress assessment consist of 5 components: 3 mini-tests and 2 lab group reports (avaliation type B, according to the FCT-UNL assessment rules).
• Course success requires an average positive grade (NR) in the 2 lab reports (R₁ and R₂):

NR=(R₁+R₂)/2 > 9.5

• The students with an average grade in the three mini-tests, equal or superior to 9.5 in a ranking of 20 have exemption from final examination. The student needs to have in each frist test at least a grade of 6.0:

NT=(T₁+T₂+T₃)/3 > 9.5  com T₁,T₂,T₃> 6 in 20

• Student success in course requires a final examination or a mini-tests average grades of at least 9.5 in a ranking of 20. The final grade will be a weighted average of the final exam grade or mini-tests average grade (75%) plus lab reports grade  (25%):

  NF=0.75 (NF or NE) + 0.25 NR > 9.5    (NT or NE)>9.5 e NR>9.5

• Note: Assessment grades are in a range of 0 to 20 (100%).

Subject matter

Introduction to metallic materials

• Pure metals and alloys – example of commercial alloys;
• Vitreous and crystalline (monocrystalline and poly crystalline) materials;
• Main crystalline arrangements in metallic materials ;
• Microstructure. Notion of phase, grain, and grand boundaries;
• Solid solutions (substitutional and interstitial). Ordered phases;
• Examples: system Cu-Zn and beta e beta’ phases of brasses;
• Introduction to metallography. Metallic samples preparation and observation.

 Phase equilibrium diagrams

• Thermodynamic fundaments. Chemical equilibrium and Gibbs’ Phase Rule;
• One component phase diagrams (p-T diagrams), binary and ternary phase diagrams;
• Prevision of equilibrium microstructures and structural compositions.
• Main case studies: common gold (Au-Cu)  and silver ( Ag-Cu), alloys, cupronickell alloys (Cu-Ni), pewter and brazing Sn-Pb alloys ;
• Non equilibrium microstructures: coring and metastable or unexpected phases.
• Case studies: steels and cast irons (Fe-C), brasses (Cu-Zn) and Bronzes (Cu-Sn).

 Atomic diffusion

• Fick''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s first and second laws;
• Interstitial and substitutional diffusion;
• Typical solution of Fick’s second law;
• Main case studies: homogenising, carburizing or decarburizing of steels and B doping in Si wafers.

 Phase transformations

• Notion of nucleation and growth;
• Theory of nucleation. Homogeneous and heterogeneous nucleation;
• Solidification in pure metals and alloys.  Constitutional Supercooling: cellular and dendritic growth;
• As cast structures. Segregations. Defects and other compositional heterogeneities in cast metals;
• Some examples of as cast structures and solidification defects in ferrous alloys
• Solid state transformations. diffusional and martensitic  (diffusioneless) transformations in solids.
• Nucleation in solid phase transformations
• The time-temperature-transformatiom diagrams.
• Examples: typical TTT diagrams for hipoeutectic steels.

 (This course has an internet page in Moodle plataform: http://moodle.fct.unl.pt/)

Programs

Programs where the course is taught: