After successful completion of the course, students are able to:
- understand the relationships between atomic bonds, crystal structures and the resulting material properties.
- describe the effects of defects in the crystal structure. (Materials are like people: Defects make them interesting) No ruby without "defects" in its corundum structure.
- understand how crystal nuclei form and grow.
- explain the diverse structural phenomena of the materials (using steel and cast iron as examples, we will discuss corresponding phase changes and the resulting microstrutcure).
- to understand that especially the 1-dimensional crystal defects (so-called dislocations) contribute significantly to the specific properties of metals.
In particular, after positive completion, students will be able to:
- explain why single crystals are transparent or not transparent
- describe the binding potential well and explain its relationship to melting point, Young's modulus, and coefficient of thermal expansion
- calculate Miller indices for cubic and hexagonal systems
- understand crystal systems, Bravais lattice
- calculate the theoretical density and the ratio of the lattice gaps to the atoms in a crystal lattice
- justify why C has a different solubility in the fcc and bcc Fe crystal lattice, and this is contrary to the packing density of bcc or fcc Fe
- understand what cementite is and how intermetallic phase formation occurs
- understand why and how substitutional solid solutions or interstitial solid solutions are formed
- explain what the Hume-Rothery rules say and what a slight or strong violation of these rules causes.
- explain why ordered phases (superlattice structures) are formed and how they contribute to mechanical or electrical properties
- explain what intermetallic phases are and how Hume-Rothery phases differ from Hume-Rothery rules
- explain what X-rays are and how they are formed
- understand what is required for spinodal decomposition and why it is also called uphill diffusion
- to describe Fick's laws, to explain their connection, and to explain when they are valid and when not
- understand why fcc metals are typically easier to deform than bcc metals
- understand why hcp metals like to deform plastically via mechanical twinning rather than dislocation motion
- understand the importance of dislocations in metallic materials, how they are formed and how they contribute to plastic deformation as well as hardness enhancement in metals
- name and explain the mathematical descriptions important to dislocations
- explain and understand the four strengthening mechanisms and their mathematical descriptions
- to describe the Peierls barrier and to explain why here bcc and fcc metals are different
- Understand recovery and recrystallization in metals and how this relates to the defects required for this to occur.
- explain why there are four strengthening mechanisms and not more and not less
- explain why the elastic properties of crystals can often be different in different crystallographic directions
- To derive various important laws and equations such as: Bragg equation, Schmid's shear stress law, energy estimation of dislocations, nucleation rate, nucleus growth rate, Fick's laws
- describe the common hardness testing methods and explain the relationship between Vickers and Brinell
- explain why 100 HRC is the highest value provided by the HRC method
- explain why heterogeneous or homogeneous nucleation occurs
- explain and understand why sometimes homogeneous nucleation is faster than heterogeneous nucleation
- interpret a CCT and TTT diagram and draw it for hypoeutectoid, eutectoid and hypereutectoid steels
- explain the difference between pearlite, bainite, and martensite
- explain the difference between lath and plate martensite
- describe shape memory alloys and explain their one-way and two-way effects
- describe superplasticity and superelasticity
- explain how cubic martensite is formed
The course is given in German AND English.
During the prolog on Mo. Oct. 3rd (2:00 pm, FH HS1) there will be an information session, in which the course of the lecture as well as the examination will be explained. In addition, the historical development of materials will be briefly presented and the special features of metallic materials (such as combination of toughness and strength) will be explained with examples.
Vorlesungstermine!
On Mondays (14:00 - 16:00 o'clock, as presence lecture at the FH HS1), the lecture is given in German. The first unit will be given on the 1st Monday in October.
On Tuesdays (12:15 - 13:45 am, as a presence lecture in the Vortmann HS), the lecture is given in English.
Written and oral Exam!
Both parts of the exam (written and oral) need to be positive (>50 %).
During the lecture, it is possible to take part in the offered small tests (about 15 min, immediately before four of the mentioned lecture dates). The exact dates will be announced during the lecture, a week earlier. The points obtained will be added to the points of the written exam, if the exam is performed within the same year of study and at least 50% are obtained for the written part. It is not possible to worsen the result of the exam by taking part at the small tests.
The exams, written or oral, are based on the script.
Written part: Mandatory for all students. A written exam is typically structured in 7 subsections (which cover the entire lecture content). Part of any written exam is the iron-carbon diagram, corresponding cooling curves, and the usage of the lever-rule.
Oral part: The oral exam is mandatory if the written part was between 50 and 55%, or if major sections of the written exam were below 50%. From the 3rd examination-entrance onward, an oral examination is always required for a positive assessment. Typically, the oral part is 1-3 weeks after the written part. Procedure: 1h per group of 4-5 students (online or in the BE building 4. floor).
Covid-specific: Written exams are held as attendance exams, if permitted. If not allowed, online exams (via zoom) will take place on the dates indicated. Details will follow a few days before the respective exam dates. In any case, please register in time for the desired dates and consider the conditions given at TUWEL.
The course is based on individual chapters of the lecture-book of G. Gottstein "Physical Foundations of Materials Science". This book is recommended for the lecture and the exam preparation.
The script (also in English and color) is available at the first lecture, after that in the office of the institute (9-12 and 13-17 clock), Getreidemarkt 9 (building BE, 4 floor).
