Topics for midterm exams of Advanced materials and technologies

  1. What does the metallic character mean? What is the role of it in determining material properties? (the peculiarity of the electron configuration and the result of this) (3 example)
  2. How phase relations, which are derivable from phase diagrams, affect the material properties?

-resistivity, hardness, strength, possibilities for strength-enhancing (which technology is adaptable: precipitation, solution hardening, etc.), properties and structure of layers, etc. (3 example)

  1. Briefly describe the types of metastable states! What are the role of these in strength enhancing? (3 example)
  2. What is the connection of structure (atomic order, lattice structure) with the types of metastable state?
  3. What does the „size effect” mean (ultrafine grain, nano particle, cluster)? How do they affect material properties? In what practical cases do these occur?
  4. What kind of atomic processes and/or phase transformations are behind the strength-enhancing mechanisms? How do they develop their strength-enhancing effect?
  5. What is the connection between strength-enhancing mechanisms and the equilibrium phase relations (shape of the phase diagram)?

-What are the conditions for the precipitation hardening or the strength increase caused by the dissolved atoms?

-How the equilibrium phase relationships determine that which strength-enhancing mechanism can be applied?

  1. What does the ageing caused by interstitial atoms mean? What does aging mean for mechanical properties?
  2. How does the shape of the phase diagram affect the machinability for light metals?

-shapability, moldability, thixo shaping

  1. What is the role of the quality certificate of the manufacturer?What are the most important parts, data of it?
  2. What are the most important properties of sheet products in terms of technology that are involved in the selection (normal anisotropy, planar anisotropy, strain hardening coefficient, Forming Limit Diagram)?
  3. What are the possibilities of absorbing gases in metals (in what kind of phases)?How does dissolution enthalpy influence the conditions of dissolution (temperature dependence, amount of dissolved atoms)?
  4. How are the conditions of dissolution and concatenation of gases affected by the phase conditions (phase diagram) of metal-gas system? (shape of saturation curve)
  5. What does surface modification mean? What are the goals for surface modification technologies?
  6. What factors play a role in choosing a surface technology?
  7. What is the difference between CVD and PVD process? What are their advantages and disadvantages?
  8. Why can we talk about a Diamond-Like Carbon layers?
  9. What types of surface modifications do the laser beam technologies provide?
  10. What are the advantages and disadvantages of using ceramic raw materials compared to metallic alloys? How do these differences arise?
  11. How can the elasticity modulus and the coefficient of thermal expansion from the potential curve of chemical bond (primarily ionic) be deduced? How does bond strength affect these properties?
  12. What are the major structural changes in ceramics (polymorphic transformations, glass transformation)?
  13. What is the mechanical character of ceramics? What kind of stress (types)can be applied?
  14. Which physical properties affect the thermal stresses in the case of ceramic components? How does the stress field depend on the thermal process is applied (heating, cooling)?
  15. What are the most important steps in the production of modern technical ceramics (especially pressing and sintering processes)? How do they influence the quality of the final product? What are the basics of glassware production technologies?
  16. What should we consider when designing ceramic components?
  17. What are the aspects of the choice of material pairs in composite materials?
  18. What properties can be affected by the structure of composite materials? What are the most important relationships between composite product structure and mechanical properties (taking into account high temperature operating conditions)?
  19. What is the reason for the isotropy/anisotropy of composite products/elements?
  20. Which specific material properties usually used to compare the reinforcing fibers?
  21. What factors and attributes can justify the choice of metal, ceramic or composite material?
  22. Melyek a polimerek legfontosabb szerkezeti módosulatai?
  23. Polimerek szerkezete hogyan hat a legfontosabb tulajdonságokra? Mi a szerepe a molekulatömegnek?
  24. Miben más a polimerek -ε karakterisztikája a fémes ötvözetekhez képest? A polimerek milyen mechanikai jellemzői adódnak ebből (feszültség relaxáció, kúszás, belső veszteség …)?
  25. Melyek a polimerek legfontosabb termomechanikus jellemzői (fontosabb hőmérsékletek és az általuk meghatározott tartományokhoz köthető viselkedés)?
  26. Mi a jelentősége az oldószer, ill. nedvességfelvételnek polimerek esetén?
  27. Milyen okokra vezethető vissza, és mit befolyásol a polimerek öregedése?
  28. Melyek a polimerek legfontosabb anyagvizsgálati módszerei (keménységmérés, DMA, TMA, nedvességtartalom meghatározása, DTA/DSC, termogravimetria, HDT, Vicat)? Mi ezek lényege röviden?
  29. Melyek a fázis/szövetelem azonosításának lehetőségei és lépései fémes ötvözetekben?
  30. By assuming an isotropic, elastic-plastic material model, how can the material model be given using the results of a tensile test (elasticity range, elasticity and hardening criterion)?