Leakages from seals are one of the important factors that are taken into consideration while designing any machining element. This is because leakages can affect the performance of any component and can also turn into a catastrophe. If looked into it, many parameters can be pointed out that can enhance leakages within the system, some of them may be pressure, temperature, clamping force and bolt distance etc. But the main parameter is the surface roughness, higher the roughness more the leakage and vice-versa. Thus, in this thesis an attempt has been made how the surface roughness can affect the performance of the sealing concept for metal bounded gasket with above four mentioned parameters. Also how leak proof surface can be defined using standard tribological parameters is the aim of this thesis. This report includes the results for methodologies implemented during the thesis and track down the leakages. The leaked surfaces were carefully studied and analyzed using different standards compared with the non leaked surfaces’ roughness parameters. / Läckagerisk från tätande förband är en av de viktigaste faktorerna som beaktas vid utformning av konstruktionsartiklar. Detta på grund av att konsekvenserna kan bli förödande. Det tätande förbandet påverkas av många olika parametrar såsom till exempel tryck, temperatur, klämkraft, skruvavstånd och val av packning. En viktig faktor är ytans beskaffenhet; Generellt läcker en grov yta och vågig yta mer än en fin och plan yta. Således har i denna avhandling ytans beskaffenhet studerats tillsammans med en packning av typen metallburen gummipackning för att påvisa täthetfunktionen som en funktion av tryck, temperatur, klämkraft och skruvavstånd. Denna rapport innehåller resultat och analys av olika standardmetoder för de ytor som ingick i utredningen.

A característica de superfície representa um fator importante na previsibilidade do comportamento dos materiais cerâmicos quanto ao desgaste. A rugosidade superficial de duas cerâmicas (Duceram Plus e Duceragold) foi avaliada através de dois métodos - análise quantitativa e qualitativa - após diferentes tratamentos. Foram confeccionados 36 corpos de prova de prova para a análise ao rugosímetro, e 24 corpos de prova para a análise ao MEV. Os resultados destas análises demonstraram o comportamento distinto entre os diferentes tratamentos. A análise com o rugosímetro demonstrou que a ação dos polidores EDENTA foi a mais efetiva para devolver lisura à superfície após a realização de desgaste com instrumento abrasivo diamantado rotatório. Todas as técnicas de polimento acarretaram em valores de rugosidade menores que os observados nos espécimes que foram submetidos apenas os “glaze". Entre as cerâmicas avaliadas, a Duceragold apresentou valores médios de rugosidade inferiores aos observados na porcelana Duceram Plus na maioria dos tratamentos pesquisados. Pela análise ao MEV não foi possível distinguir diferenças entre as cerâmicas ou entre os corpos de prova polidos ou submetidos apenas ao “glaze". / The surface characteristic of ceramic material is an important factor to predict its wear behavior. The surface roughness of two ceramics (Duceram Plus e Duceragold) was evaluated trough qualitative and quantitative methods after different treatments. 36 specimens were fabricated for the analysis utilizing a surface profiling instrument, and 24 for the SEM analysis. The results determined different behavior between the two ceramics evaluated due the treatment executed. The analysis utilizing a surface profiling instrument showed that the treatment using the EDENTA polishers was the most effective technique to provide the smoothest surface after trimming. All polishing techniques resulted in better surface properties when compared to the treatment glaze. The Duceragold ceramic presented lower roughness values in most treatments executed when compared to Duceram Plus. The perception trough the SEM analysis of significant differences between treatments or between the two ceramics was not achievable.

A característica de superfície representa um fator importante na previsibilidade do comportamento dos materiais cerâmicos quanto ao desgaste. A rugosidade superficial de duas cerâmicas (Duceram Plus e Duceragold) foi avaliada através de dois métodos - análise quantitativa e qualitativa - após diferentes tratamentos. Foram confeccionados 36 corpos de prova de prova para a análise ao rugosímetro, e 24 corpos de prova para a análise ao MEV. Os resultados destas análises demonstraram o comportamento distinto entre os diferentes tratamentos. A análise com o rugosímetro demonstrou que a ação dos polidores EDENTA foi a mais efetiva para devolver lisura à superfície após a realização de desgaste com instrumento abrasivo diamantado rotatório. Todas as técnicas de polimento acarretaram em valores de rugosidade menores que os observados nos espécimes que foram submetidos apenas os “glaze”. Entre as cerâmicas avaliadas, a Duceragold apresentou valores médios de rugosidade inferiores aos observados na porcelana Duceram Plus na maioria dos tratamentos pesquisados. Pela análise ao MEV não foi possível distinguir diferenças entre as cerâmicas ou entre os corpos de prova polidos ou submetidos apenas ao “glaze”. / The surface characteristic of ceramic material is an important factor to predict its wear behavior. The surface roughness of two ceramics (Duceram Plus e Duceragold) was evaluated trough qualitative and quantitative methods after different treatments. 36 specimens were fabricated for the analysis utilizing a surface profiling instrument, and 24 for the SEM analysis. The results determined different behavior between the two ceramics evaluated due the treatment executed. The analysis utilizing a surface profiling instrument showed that the treatment using the EDENTA polishers was the most effective technique to provide the smoothest surface after trimming. All polishing techniques resulted in better surface properties when compared to the treatment glaze. The Duceragold ceramic presented lower roughness values in most treatments executed when compared to Duceram Plus. The perception trough the SEM analysis of significant differences between treatments or between the two ceramics was not achievable.

The addition of lead to the copper alloys increases its machinability and reducesthe overall production cost, despite copper being expensive, which makes achallenging task to replace lead. But the alarming effects of lead on human healthand the recycling problems has led to the increase in concern forreducing/eliminating the use of lead in brass and other copper alloys. Manymaterials are considered to replace lead in brass; silicon is one such alternative.The turned brass sample are investigated using the state of the artequipments at Halmstad University. The results obtained are controlled readingsof surface parameters and is categorized using surface imaging and mappingsoftware, Mountains Map.This thesis characterizes the lead and the lead free brass's surfaceintegrity for a certain cutting data. The study deals with the evaluation ofselection of appropriate surface integrity parameters and summarizes theappropriate combination of cutting data to maintain the surface of the ecobrass/unleaded brass on par with the leaded brass surface. The 2D and 3Dsurface parameters illustrates the surface functionality and its effect on thematerial in contact.The research results suggest a detailed methodology for the analysis ofsurface topography and a comparison exemplifying differences between the twomaterials under study. The research provides a perplexed results and forms thebasis for further investigations of the samples machined at different cutting data.Second set of test includes comparing the Leaded brass with the unleaded brasssamples machined at 0.06, 0.1, 0.15 and 0.2mm/rev respectively. The studyfocuses on the correlation of cutting feed and the surface parameters. Comparingthe results of two tests, the unleaded brass machined @ feed rate 0.2mm/rev,200m/min, 1.5mm depth of cut posses similar surface functionality as leadedbrass.