Thesis (M.F.A.)--Rochester Institute of Technology, 2009. / Typescript. Includes bibliographical references (leaves 46-47).

Thesis (M.S.)--University of Wisconsin--Madison, 1967. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1968. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 94-96).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

No description available.

The unlubricated sliding wear behaviour of gas nitrided, plasma nitrided, and ferritic nitrocarburized BS970,905M39 (EN41B) steels was investigated systematically from an engineering point of view. Commercial nitriding processes were employed, and the wear studies were carried out using a pin-on-disc machine over a wide range of sliding speeds and applied loads. The worn specimens and wear debris were examined by several techniques; including optical and electron microscopy and X-ray analysis. A sharp wear rate transition between mild and severe regimes was identified by varying the load for both untreated and gas nitrided steels. The wear rate was reduced by gas nitriding by up to two orders of magnitude, depending on the sliding condition. Moreover, gas nitriding expanded the mild wear region toward higher loads and sliding speeds. In the mild regime an oxidative wear mechanism operated, contrasting with the metallic wear in the severe regime. Wear maps for untreated and gas nitrided steels have been constructed, which show the dominant regimes of the wear mechanisms. A "wear-face-limited" gas nitrided pin test showed that the benefit of the treatment was lost once the effective surface layer was completely worn away. It is suggested that hardness has a crucial role in determining the wear rate through nitrided diffusion layers. A thick and porous compound layer produced by gas nitriding showed a poor wear behaviour owing to its brittleness, while a thin nitrocarburized E-Fe3N compound layer exhibited a low wear rate. There was no significant difference between the nitride steels in terms of transition load and wear rate. However, the wear lives of the nitrided layers were dependent on their case depth. Severe wear should be avoided in engineering component design, and operating conditions should ensure that only mild wear occurs. Both the hardness profiles and the cost performance of nitriding processes should be considered in the selection of nitriding treatments.

Metal Matrix Composite (MMC) coatings, comprised of a hard ceramic phase embedded in a metallic matrix, are increasingly being applied for many industrial applications to provide cost effective protection against wear and corrosion. Such coatings are commonly produced by thermal spray. Although the most advanced thermal spray techniques, such as high-velocity oxy-fuel (HVOF), produce MMC coatings with total porosity levels lower than 1%, due to the nature of thermal spray MMC coatings, corrosion still takes place. The corrosion processes are dominated by the complex microgalvanic and interfacial mechanisms, as well as by porosity, due to the existence of various defects in HVOF MMC coatings. As a result, HVOF coatings do not ultimately meet the requirements in certain service conditions in operating environments. Therefore, there is a need to find a method of modification of coatings, with significantly reduced microstructural defects and improved cohesive and adhesive strength so that the service life of the coated components can be increased. This work aims to investigate the effects of laser surface treatment on the corrosion and wear performance for Tribaloy 800 (T800), and T800-based WC HVOF-sprayed MMC coatings onto 316L stainless steel substrate. Laser surface treatments have been carried out using a 1.5 kW high power diode laser. Laser operating windows for various coatings have been established for the relationships between the laser operating conditions and melt pool dimensions, in the consideration of formation of cracks and porosity within laser-treated surface layers. Microstructural analysis of the powders, and various coatings before and after laser treatments has been conducted by means of optical and SEM (with EDX) microscopy, electron probe micro-analysis (EPMA), white-light interferometery, and X-ray diffraction, to characterise morphology, chemical composition and phase. Corrosion performance of various coating was evaluated using immersion testing in 3 M H2SO4 at pH ~ 1.27 at room temperature for different periods of time (including 24, 48, 72, 96 and 168 hours), followed by Inductivity Coupled Plasma-optical emission spectrometer (ICP-OES) technique, potentiodynamic polarisation in 0.5 M H2SO4, and electrochemical impedance spectroscopy studies in 0.5 M H2SO4 solution after 1, 3, 6, 12, 24, and 48 hours. Inaddition, dry sliding wear behaviour measured by pin-on-disk and microhardness test of various coatings before and after laser treatment were evaluated.The results indicated that it was possible to achieve full control of melt depth and the degree of melting, particularly full or partial melting of WC particles by proper selection of the laser processing parameters while preventing dilution. Significant improvement of corrosion and wear resistance has been achieved after laser treatment as a result of the elimination of discrete splat-structure, removal of microcrevices and porosity, as well as the reduction of microgalvanic driving force between the WC and the metal matrix by formation of new phases at the interfaces. The degree of melting of WC particles controls the corrosion properties of the laser-treated HVOF coatings. Moreover, the results also suggested that partial melting of WC had positive effect on wear resistance of the coatings.

M.Ing. / This report documents the steps taken to gain insight into the dynamics of a HS MkVII self-steering three piece bogie. This was done by firstly studying the dynamics and stability of linear simplifications of the bogie and wagon and then by investigating the dynamics of the bogie by means of a non-linear model.With the necessary insight into the dynamics of the bogie, an optimised relationship between the primary suspension stiffness and the centre plate friction of a self-steering three-piece bogie was achieved. The optimised model’s wear is less than half that of the reference model and has a safe operating speed of 80km/h for an empty wagon and 140 km/h for a loaded wagon. It is recommended that the following be done before issuing a final technical recommendation; • A final optimisation of the lateral and longitudinal primary suspension stiffness arrangement; taking into consideration the physical vertical load bearing capacity of the rubber suspension elements. • A study in order to quantify the effects, on wear, of the increased misaligned position of the bogie on straight track following a curve. A verification of the ADAMS/Rail simulation results by conducting specific on-track tests. • A comprehensive cost-benefit analysis.

This thesis examines Flora Krauch’s use of Progressive Era social reform methods to develop and expand infants’ and children’s merchandise departments in American department stores and specialty shops. Krauch used the pages of the industry’s first trade journal, The Infants’ Department, to wage her battle against the commercialization of these departments, and to urge the use of mother education and child welfare as their foundation. At the turn of the twentieth century, retailers began to demonstrate their civic leadership in socially responsible ways. By 1916 independently owned department stores faced new forms of competition which led them to build alliances with individuals who highlighted the significance of scientific management methods and commercialization. The Retail Research Association and Harvard Business School spearheaded these merchandising shifts. The effects of these trends are apparent in children’s departments. To explore how Krauch rejected commercialization, this thesis analyzes all available newspaper and journal articles Krauch wrote from 1909 to 1940, as well as primary sources from the U.S. Children’s Bureau and Harvard Business School. Krauch was a leading force in the effort to challenge commercializing forces through the professionalization of women in retail buying and sales, and through the education of mothers about the health and safety of infants’ and children’s merchandise.