Techn. Univ., Diss., 2003--Darmstadt

Techn. Hochsch., Diss., 2003--Aachen.

Techn. Universiẗat, Diss., 2004--Darmstadt.

Techn. Universiẗat, Diss., 2004--Berlin.

University, Diss., 2005--Hamburg.

Techn. Universiẗat, Diss., 2005--Darmstadt.

Inaug.-Diss.--Philosophische Fakultät--Universität zu Köln, 1993. / Contient des statistiques. Notes bibliogr. Bibliogr. p. 791-810. Notices biogr.

In sheet metal forming (SMF) of materials such as stainless steels there is a major problem with transfer and accumulation of sheet material to the metal forming tool surface. The problem is known as galling; a sort of severe adhesive wear, which results in severe scratching of produced parts. In this thesis, the overall aim was to gain knowledge of the influence of tool steel microstructure on galling initiation under sliding conditions. It was discovered that material transfer and tool steel damage caused by sheet material flow creating wear-induced galling initiation sites occurred in the early stage of galling. The galling resistance was higher for tool steels with higher matrix hardness due to better resistance to tool steel damage. Initial friction and critical contact pressure to galling was influenced by the strength of the sheet material. Material transfer happened at low pressures and the friction value was high in a case of sheet materials with lower proof strength, possibly due to the sheet contact against the tool steel matrix resulting in high adhesion and quicker tool damage. It was demonstrated that, in addition to hardness of the tool steel matrix and sheet material proof strength, tool steel microstructural features like size, shape, distribution and height of hard phases are important parameters influencing galling. Tool steels comprising homogeneously distributed, small and high hard phases better prevented the contact between sheet material and the tool steel matrix. Thus, a metal to metal contact with high friction was more efficiently avoided, which resulted in better tool performance.

Advances in flexible and functional metal–organic frameworks (MOFs), also called soft porous crystals, are reviewed by covering the literature of the five years period 2009–2013 with reference to the early pertinent work since the late 1990s. Flexible MOFs combine the crystalline order of the underlying coordination network with cooperative structural transformability. These materials can respond to physical and chemical stimuli of various kinds in a tunable fashion by molecular design, which does not exist for other known solid-state materials. Among the fascinating properties are so-called breathing and swelling phenomena as a function of host–guest interactions. Phase transitions are triggered by guest adsorption/desorption, photochemical, thermal, and mechanical stimuli. Other important flexible properties of MOFs, such as linker rotation and sub-net sliding, which are not necessarily accompanied by crystallographic phase transitions, are briefly mentioned as well. Emphasis is given on reviewing the recent progress in application of in situ characterization techniques and the results of theoretical approaches to characterize and understand the breathing mechanisms and phase transitions. The flexible MOF systems, which are discussed, are categorized by the type of metal-nodes involved and how their coordination chemistry with the linker molecules controls the framework dynamics. Aspects of tailoring the flexible and responsive properties by the mixed component solid-solution concept are included, and as well examples of possible applications of flexible metal–organic frameworks for separation, catalysis, sensing, and biomedicine.

On February 4th in 1738, Daniel Tilas, an official of the Swedish Bureau of Mines travelled into Russia in order to study the metal and mining industries of the country. After just over two months of travelling between workshops, factories and mines, both abandoned and active ones, he returned home to Sweden with a rather rich description of his findings in Russia. During the early modern era travels like this one, namely with the purpose of gathering and describing knowledge, were a commonplace occurrence all over Europe. The Bureau of Mines sponsored many travels of this sort during it’s roughly 200-year existence in order to gain knowledge of the state of the metal and mining industries around Europe and even in Sweden, these travels also functioned as a crucial part in the education of the Swedish mining officials. But the Swedish travels to Russia were undertaken with partially different goals in mind, since the end of the great northern war Russia hade become the primary enemy on Sweden. This meant the Bureau of Mines sought after knowledge about and from Russia which could be used to effectively compete against them on a geopolitical scale. In this essay I thus attempt to explore the view of Russia which existed in the Bureau of Mines during the first half of the 18th century by primarily studying how Tilas depicted the Russian mining and metal industries and secondarily the Russian society in his writings. I do this through the analytical lens of the theory on “state-related knowledge” defined by historians Lothar Schilling and Jakob Vogel. I also make use of the concept of the “hybrid expert” as defined by historian Ursula Klein to deepen the analysis of Tilas depiction and description of Russia’s industry.