University of Silesia in Katowice

In modern world new materials are being invented and synthesised every day for their application in diverse areas – batteries, gas storage, pharmaceuticals, electronics, etc. Knowledge on atomic arrangement is crucial for designing their properties. The elucidation of the atomic arrangement is a key role of crystallography. Crystallographic analysis is based on collection experimental data in diffraction space and processing the data in order to obtain information on the structure of materials. Crystallographic concepts were developed about a century ago, and since that were effectively used to solve more than a million of crystalline structures. Traditionally, the diffraction experiment is performed with X-rays, recently electrons showed its power in resolving crystal structures. In this lecture general crystallographic concepts and well as a workflow for structure analysis will be introduced. Differences between X-ray and electron diffraction data will be outlined.

Diffraction methods play an important role in determining the structure of different forms of materials (single crystal, poly crystal, amorphous and even liquids and gases). In contrast to neutrons and x-rays, electrons interact with material very strongly, facilitating examination of very small volumes of material. The lecture will present computer program assisted processing of electron diffraction patterns from solid materials in the transmission electron microscope (TEM). Although diffraction in itself does not need lenses, the presence of lenses in a TEM creates the possibility to correlate direct-space and reciprocal-space information. Even a submicroscopic grain can be examined as an individual single crystal in a TEM. The ProcessDiffraction Suite contains procedures for indexing single crystals from selected area (SAED) or nanobeam (NBD) diffraction patterns, determine orientation of crystallites from Kikuchi patterns and determine misorientation between neighboring grains, identify phases from polycrystalline ring patterns and determine nearest neighbor distances for amorphous materials from the diffuse diffraction patterns. Phase distribution and orientation distribution in nanocrystalline materials is also deduced from a large set of NBD patterns collected in four-dimensional electron diffraction (4D-ED) mode in a scanning transmission electron microscope (STEM), where a 2D NBD pattern is recorded at each pixel of a 2D area scanned by the electron beam. The shown program suite is also available free for the participants of the school.

Fatigue fractures are generally considered the most serious type of fracture in machinery parts simply because fatigue fractures can and do occur in normal service, without excessive overloads, and under normal operation conditions. The main problem is, that fatigue fractures are insidious, that is, they are frequently „sneaky“ and can occur without warning. The aim of this lecture is to explain the physical nature of the fatigue phenomenon and describe the damaging mechanisms, which lead to fatigue fractures of structural components.

To be able to predict the components behavior and durability during cyclic loading, still the only reliable way is to subject the material to fatigue testing, or even to test final component. To maximize the knowledge obtained from the testing process, the test conditions must reflect as close as possible the expected loading in the final application. The aim of the lecture is to explain the different types and aspects of fatigue loading and enable the students to adopt the proper mindset for designing a fatigue testing experiment.

High-strength steels are a type of steel that has been specially developed to have higher strength and hardness than conventional steels. These steels are typically used in structural and engineering applications where high strength and low weight are important. There are several types of high-strength steels, including: high-strength low-alloy steels (HSLA), martensitic steels (MS), bainitic steels (BS), and quenched & tempered steels. High-strength steels are typically more expensive than traditional steels due to the additional processing and alloying required to produce them. However, their higher strength and lower weight can provide significant benefits in certain applications, such as in the construction of bridges, buildings, and vehicles. The lecture will cover several important topics related to high-strength steels, including: the different types of HS steels, strengthening methods, properties, applications, processing, and costs.

Diffraction methods play an important role in determining the structure of different forms of materials (single crystal, poly crystal, amorphous and even liquids and gases). In contrast to neutrons and x-rays, electrons interact with material very strongly, facilitating examination of very small volumes of material. The lecture will present computer program assisted processing of electron diffraction patterns from solid materials in the transmission electron microscope (TEM). Although diffraction in itself does not need lenses, the presence of lenses in a TEM creates the possibility to correlate direct-space and reciprocal-space information. Even a submicroscopic grain can be examined as an individual single crystal in a TEM. The ProcessDiffraction Suite contains procedures for indexing single crystals from selected area (SAED) or nanobeam (NBD) diffraction patterns, determine orientation of crystallites from Kikuchi patterns and determine misorientation between neighboring grains, identify phases from polycrystalline ring patterns and determine nearest neighbor distances for amorphous materials from the diffuse diffraction patterns. Phase distribution and orientation distribution in nanocrystalline materials is also deduced from a large set of NBD patterns collected in four-dimensional electron diffraction (4D-ED) mode in a scanning transmission electron microscope (STEM), where a 2D NBD pattern is recorded at each pixel of a 2D area scanned by the electron beam. The shown program suite is also available free for the participants of the school.

In modern world new materials are being invented and synthesised every day for their application in diverse areas – batteries, gas storage, pharmaceuticals, electronics, etc. Knowledge on atomic arrangement is crucial for designing their properties. The elucidation of the atomic arrangement is a key role of crystallography. Crystallographic analysis is based on collection experimental data in diffraction space and processing the data in order to obtain information on the structure of materials. Crystallographic concepts were developed about a century ago, and since that were effectively used to solve more than a million of crystalline structures. Traditionally, the diffraction experiment is performed with X-rays, recently electrons showed its power in resolving crystal structures. In this lecture general crystallographic concepts and well as a workflow for structure analysis will be introduced. Differences between X-ray and electron diffraction data will be outlined.