The heavy-vehicle automotive industry is constantly subjected to higher demands. In particular, new European emission standards are formulated with the intention of improving the environmental friendliness of newly-produced vehicles through reduced exhaust emission. In one way or another, this implies a successive improvement of the engine efficiency, which in turn, inevitably will require a higher combustion pressure and temperature. This is a respectable challenge for future engine constructions, but also for the engineering materials used to embody them. As higher thermal and mechanical loads must be sustained, there is a higher rate of wear, and consequently, a negative effect on the extent of the engine lifetime. The aim of the present thesis is to confront the expected increase in rate of wear, henceforth referred to as fatigue, by studying the effect on materials typically employed in heavy-vehicle engines, namely cast irons. Foremost, the intention has been to improve the understanding of the physical mechanisms of fatigue in these materials, in order to develop a lifetime estimation method designated to assist the mechanical design of heavy-vehicle engines. In essence, a large set of thermo-mechanical fatigue (TMF) and combined thermo-mechanical and high-cycle fatigue (TMF-HCF) tests has been conducted at engine load conditions on laboratory specimens of lamellar, compacted and spheroidal graphite irons. In this way, these three different material groups have been experimentally compared and the associated fatigue mechanism has been studied. In particular, a new property related to TMF-HCF conditions has been identified and measured, . Regarding the fatigue mechanism, it has been affirmed to consist of the initiation, propagation and coalescence of numerous microcracks. Based on this, a successful lifetime assessment model was formulated, allowing good estimations of the fatigue life of laboratory specimens subjected to both TMF and TMF-HCF conditions.

The essay addresses the question "Can a new context for a material change the experience of it?" The materials used in the work are carabiner, tile and industrial net. I go through my perceptions about the materials and try to explain what one could do with them instead in a furniture context. I tell you about my inspiration I have had before and during my work and present how my ideas have evolved during the process. The end result is a clothes rack with the carabiner, a display shelf with the tile and a wall hung shelf with the industry net. Since the question is highly subjective, I have chosen to answer it from my own perspective. The short answer is yes

Thesis (Ph. D.)--Drexel University, 2004. / Includes abstract and vita. Includes bibliographical references (leaves 149-154).

The algorithm of arc spraying process simulation was created, which allow to make prognosis of arc spraying jet configuration and flying particles parameters. This scientific research shows the dependence between the arc spraying technological parameters and mechanical and physical properties of the obtained coatings. It was established, how by change of the spraying parameters the coatings with the best exploiting parameters can by received. The performed research shows the influence of the kind of the sprayed material on morphology of the formed jet particles and on technical and structural characteristics of the formed coatings. On basis of obtained results made suggestions how to improve the creation of thermal spraying coatings making new products or making restoration.

The algorithm of arc spraying process simulation was created, which allow to make prognosis of arc spraying jet configuration and flying particles parameters. This scientific research shows the dependence between the arc spraying technological parameters and mechanical and physical properties of the obtained coatings. It was established, how by change of the spraying parameters the coatings with the best exploiting parameters can by received. The performed research shows the influence of the kind of the sprayed material on morphology of the formed jet particles and on technical and structural characteristics of the formed coatings. On basis of obtained results made suggestions how to improve the creation of thermal spraying coatings making new products or making restoration.

Thesis (Ph. D.)--Drexel University, 2005. / Includes abstract and vita. Includes bibliographical references (leaves 120-127).

Thesis (Ph. D.)--Drexel University, 2005. / Includes abstract and vita. Includes bibliographical references (leaves 146-154).

Thesis (Ph. D.)--Drexel University, 2005. / Includes abstract and vita. Includes bibliographical references (leaves 127-132).

The intention of this thesis is to investigate the fatigue behavior of the Ti-6Al-4V alloy manufactured by the relatively new additive manufacturing process called Selective Laser Melting(SLM). SLM has been shown the interest from important industries such as the aerospace and biomedical industry for its potential of manufacturing lightweight and complex parts to net shape without the need of conventional methods like machining. Due to the short history of SLM there is little knowledge about how fatigue properties are influenced by the manufacturing process. This project aims to add to that knowledge by studying how the microstructure, surface roughness and surface morphology influences the fatigue life of SLM made Ti-6Al-4V alloys. Fatigue tests are done by conducting 3-point bending tests on SLM and conventional samples. It was found that the SLM samples only managed 9% of the fatigue life obtained for conventional samples. This was assumed to be caused by the poor surface roughness of SLM samples, acting as stress concentrations resulting in multiple crack nucleation leading to final fracture. It was also found that a surface morphology of 90°, relative to the length of the sample, had worse fatigue life compared to 60° and 30° due to the pattern of the sample being perpendicular to the applied load.

The epoxy resin mixture is used for wet filament winding load carrying and electrically insulating tubes for high voltage applications. The cured tubes are key parts of the final products which are subject to qualification. The safe function of the products generally depends on low moisture content. Visual inspection is also an important part of the quality inspection which requires some degree of transparency of the cured tubes. To prepare for future material modifications ABB wishes to evaluate the curing characteristics of some recently developed epoxy/hardener systems. The epoxy resin with the formulation E1/H1 is used as reference. Another type of base epoxy resin E2 and toughened epoxy resin E1 (E1T) are included in the study. Three alternative hardeners H2, H3, and H4 were evaluated. This project is to evaluate different alternative epoxy resin formulations that are promising to be used in the ABB products in the future. These alternative epoxy resin formulations and the reference epoxy resin with the formation E1/H1 were prepared to be compared and evaluated in terms of thermal properties, i.e., glass temperature (Tg), the heat of curing and color of cured epoxy resins. The epoxy resins with alternative formulations which shown relative high Tg values were selected to carry out other analysis, ie., mixing ration optimization, the influence of dissolved water on Tg values, degree of curing and water absorption behavior.