Ing Ind - Inf (Mag.)(ord. 270) - LC (485) MECHANICAL ENGINEERING - INGEGNERIA MECCANICA
051581 - LABORATORY OF MECHANICAL METALLURGY
The goal of the course is to give the students high specialization in materials and damage phenomena. The course concentrates on ferrous and non-ferrous alloys, focusing the attention on the relation among the metallurgical and the microstructural characteristics and the mechanical properties, the toughness and the corrosion resistance. The topics are explained and discussed both according to the technical literature, both by examples of industrial cases. Didactic visits in some metallurgical and mechanical plants are planned to enable the students to match the theoretical aspects with the practical ones.
Risultati di apprendimento attesi
At the end of the course, the students:
know the most important metallurgic aspects of special and stainless steels and non-ferrous alloys
know the relation among the microstructural features and the mechanical performance of materials
know the main metallurgical aspects of hot forming
are able to apply the metallurgical knowledge in the failure analysis of mechanical components
Plastic deformation of polycrystalline materials. Dislocation theory. Fracture. Types of fracture in metals. Metallographic aspects of brittle fracture. Dislocation theories of fracture. Ductile fracture. Brittle failure. Characteristic microstructural and morphological aspects.
Traditional and innovative methods for studying the tough-brittle behaviour of metallic materials (impact test, fracture mechanics). Fundamental issues on fracture mechanics. Brittle fracture and impact testing. Metallurgical factors affecting transition temperature. Influence of the alloying elements. Embrittlement phenomena (temper embrittlement, strain aging embrittlement, environment induced embrittlement)
Fatigue failure. Fracture mechanics applied to fatigue, morphology of the fracture surface, influence of the chemical composition, of the microstructure, of the surface conditions and of the environmental conditions. Corrosion fatigue. Fretting fatigue. Thermal fatigue. Examples of failure analysis.
Wear damage of the mechanical parts. Wear mechanisms: adhesive wear; tribo-oxidation; abrasive wear; contact fatigue. Wear processes: sliding wear; rolling wear; fretting; erosion. Wear tests. Engineering methods for prevention. Surface engineering: thermo-chemical treatments, surface coatings; surface analysis.
Creep and stress rupture. The high-temperature materials problem. The creep curve. Theories of low-temperature creep. Theories of high-temperature creep. Fracture at elevated temperature. Presentation of engineering creep data. Effect of metallurgical variables. Stress relaxation.
Mechanical behavior of metals during forming and forging. Recovery, static and dynamic recrystallization. Grain growth. Overaging.
Failure analysis and test methods: visual examination and optical microscope analysis, electronic microscope analysis, fractography, quantitative analysis, examples of failure analysis. Presentation of real cases of failure analysis
Students are required to know the basic principles of physical metallurgy, the equilibrium diagrams and the Fe-C diagram, the basic steel heat treatments and the CCT and TTT curves, the main mechanical tests and the fundamentals of steelmaking.
Modalità di valutazione
The final examination involves an oral discussion about the course contents. It will be evaluated:
the students’ knowledge of the course contents
the students’ ability to apply the studied topics to determine the cause of components failure
the students ability to apply the metallurgy knowledge to the mechanical performance of a component.