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A Study on the Creative Design of Fiber ClipsHsieh, Kuo-wei 22 August 2007 (has links)
The fiber clips is a device for holding an optical fiber which is enclosed in the ferrule, adjustment it to the optimum aligning position with respect to the laser diode and fixing it on the substrate of the butterfly-type laser module by the laser welding. It is hard for the extant saddle shaped clips to be manufactured and the result causes the unable mass production and the high cost. Otherwise, the packaging process has caused PWS of laser module, would decay the coupling efficiency of laser module.
Aim at the shortcomings, the purpose of this study proceeds to the creative design of the fiber clips with the systematic engineering design and make a set of the manufacturing method by the pressing die to cause automatic mass production in the future. First, identify the basic characteristics based on an analysis of the patents and then get the conditions and trend. Second, find the function needs and elaborate the specification of design. Third, the use of morphological analysis method and design process is formulated to synthesize and evaluate the improving structure. Finally, taking the design cases will develop the embodiment design and prove the propose approach for the design process. Otherwise, it develops an improvement technique and adjustment method for PWS and wishes can reduce or improve the effects of it.
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A Study of Post-Weld-Shift Measurement Technology in Cylindrical-Type Laser Diode Module PackagesHe, Yue-Lin 12 July 2004 (has links)
The objective of this study is to investigate the technique of the PWS (Post-Weld-Shift) measurement in cylindrical-type laser diode module packaging processes. Including measure the shift in focus plane and the run-out between the axis of laser diode and optical fiber. The objective of this technique is to quantify the PWS in packaging processes. This technique can improve the efficient of the laser hammering technique.
The measurement technique developed in this study employs a laser displacement meter (Keyence LC-2430) to measure the profile and position the upper housing of laser diode module. Using the concepts of ellipse and symmetric figure, the Ellipse Fitting Method (EFM) and the Symmetric Center Method (SCM) are developed. A simulation program is coded for discussing the relationship between the measurement error and the roundness of the optical fiber housing. Finally, these measuring technique are applied on the laser diode module packaging system (Newport-LW4000) to measure the PWS. The experimental measuring data of PWS is 3.5£gm, which is reasonable in compare to the estimate alignment offset (2.9£gm to 5.9£gm) by the coupling efficiency method. Therefore it is believed that the technique developed in this study is feasible and practical.
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A Novel Inspection of Fiber Post-Weld-Shift in Butterfly Laser Module PackagingSong, Xing-Jin 21 August 2003 (has links)
Aligning and fixing the fiber and laser device is an important work in butterfly laser module packaging. Assembling these two component by laser welding is to achieve reliable and stable weld joint. However, during the welding process, rapid solidification of the welded region and the associated material shrinkage causes the fiber position moved. The relative movement between fiber and laser is called post-weld-shift(PWS). A few micrometers PWS makes coupled power lost. Therefore, minimizing the PWS between fiber and laser is a key research topic in butterfly laser module packaging.
We can correct the PWS minimal by fiber shift inspect. But it has a difficult of space limit in butterfly laser module packaging. In this study, a video camera with image acquisition system was used to measure the PWS. We also used a mirror image to solve the problem of space limited. The PWS inspection result has matched our simulation. This method can successfully inspect the PWS in butterfly laser module.
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Development of a gleeble based test for post weld heat treatment cracking in nickel alloysNorton, Seth J. 01 October 2003 (has links)
No description available.
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Beräkningsmetoder för verifiering av svetsar med inriktning på PWT / Calculation methods for welding verification with focus on PWTPetersson, Viktor, Gustafsson, Johan January 2019 (has links)
Stål är ett material som används i olika byggnadskonstruktioner. I de byggnadskonstruktioner som utsätts för upprepade belastningar kan utmattning ske i materialet. Utmattning leder till permanenta skador i form av sprickbildning och slutligen brott. I svetsade konstruktioner är det ofta svetsar som har den lägsta utmattningsstyrkan. För att förbättra en svets utmattningsstyrka finns efterbehandlingsmetoder som benämns Post Weld Treatment (PWT). Idag används den beräkningsmetod som är föreskriven i Eurokod vid verifiering av svetsar. Beräkningsmetoden är förenklad och kan underskatta objektets livslängd med hänsyn till utmattning. Syftet med arbetet är att studera olika dimensioneringsmetoder som behandlar utmattningsbelastade svetsar samt hur tillämpning av PWT kan förbättra en typsvets livslängd. Målet med arbetet är att studera en typsvets och visa skillnaden i antalet lastcykler mellan beräkningsmetoderna samt hur många lastcykler samma typsvets förväntas öka med PWT. Teorin och resultaten utgår från vetenskapliga artiklar, litteraturstudier och enfallstudie som behandlar både en genomsvetsad stumsvets samt en kälsvets lokaliserade på en I-balk. Resultatet pekar mot att den metod som används idag underskattar livslängden och att PWT kan markant kan förbättra en svetsutmattningsstyrka. / Steel is a material used in various building structures. Fatigue can occur in the material if building structures is exposed for repeated loads. Fatigue leads to permanent damages such as crack initiations and fracture. It is common that welds in welded structures have the lowest fatigue strength. A welds fatigue strength can be improved with treatments termed Post Weld Treatment (PWT). Today a welds fatigue strength is verified with a method described in Eurocode. The calculation method is simplified which can underestimate the objects number of lifecycles regarding fatigue. The purpose with this essay is to study different structural design methods for fatigue exposed welds and how many lifecycles a typeweld will increase when applying PWT. The goal with this essay is to study a typeweld and calculate the number of lifecycles between the calculation methods and to show how many lifecycles the same type weld will increase when applying PWT. The results and theory are based on scientific articles, literature studies and a casestudy which both contains a through welded butt weld and a fillet weld placed on an I-beam. The results points at that the calculation method that is used today underestimates the number of lifecycles and that the number of lifecycles increased significant after PWT.
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Stress Relief Cracking in Low Alloy Creep Resistant SteelsSarich, Conner M. January 2021 (has links)
No description available.
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[en] MICROSTRUCTURE AND MECHANICAL PROPERTIES CORRELATIONS FOR HEATTREATED STEEL WELD METALS WITH DIFFERENT MN CONTENT / [pt] CORRELAÇÃO ENTRE MICROESTRUTURA E PROPRIEDADES MECÂNICAS EM METAL DE SOLDA COM DIFERENTESTEORES DE MN, SUBMETIDO A TRATAMENTOS TÉRMICOSRENATA GARCIA DE MIRANDA GONCALVES 14 July 2003 (has links)
[pt] Tradicionalmente, tanto os metais de solda, quanto os aço
da classe Cr-Mo, são considerados susceptíveis ao fenômeno
de fragilização ao revenido. O presente trabalho tem como
objetivo avaliar metais de solda do tipo 2,25%Cr-1,0%Mo com
diferentes teores de Mn (0,4% - 1,1%) obtidos pelo processo
de eletrodo revestido submetidos aos tratamentos térmicos
de alívio de tensões (TTAT), de step-cooling (TTSC) e TTAT
seguido de TTSC. Verificou-se através de ensaios de impacto
Charpy-V que o TTAT, promoveu um ganho de tenacidade e
resistência para teores de Mn entre 0,9% - 1,1%, enquanto
que a aplicação do TTSC não promoveu mudanças
significativas na tenacidade para todos os teores
estudados. Observou-se que, as variações microestruturais em
função dos tratamentos térmicos aplicados para uma
estrutura predominantementebainítica, detectáveis por
microscopia eletrônica de varredura, foram pequenas
para os teores de Mn estudados. A utilização dos índices
tradicionais como o fator X , fator PE e fator J de
susceptibilidade à fragilização se mostrou incompatível
com as respostas obtidas nos ensaios de impacto dos metais
de solda avaliados, sugerindo a necessidade de uma revisão
dos fatores para a avaliação da tendência para a
fragilização ou mesmo considerar que os materiais
atualmente produzidos não sejam mais susceptíveis ao
fenômeno fragilização ao revenido mesmo após tratamentos
térmicos de alívio de tensões. / [en] Traditionally, both Cr-Mo class steels and the weld metals
produced in joining such materials have been considered to
be susceptible to the phenomenon of temper embrittlement.
The current study evaluates 2,25%Cr-1,0%Mo type weld
metals with varying Mn levels (0,4%- 1,1%), produced using
coated electrodes with an SMAW process. The welded joints
were subjected to three types of heat treatment; either
stress relief annealing, or step cooling or stress relief
annealing and step cooling. Charpy-V impact testing results
indicated a gain in toughness and tensile strength for
materials with Mn levels in the 0,9% to 1.1% range, and
that the step cooling alone did not cause any appreciable
changes in toughness for any of the Mn levels studied.
Furthermore, scanning electron microscopy revealed
that the bainitic microstructure of the materials studied
was relatively little affected by the applied heat
treatments. The values obtained for the traditional
embrittlement indexes, X -Factor, PE-Factor and J-Factor
were observed to be inconsistent and incompatible with the
actual quantified impact behaviour of the weld metals
investigated. This would suggest that a reevaluation of
these traditional embrittlement indexes should be
considered. The temper embrittlement susceptibility of
steels of this type as they are currently manufactured may,
in this way, come to be considered much lower than would
otherwise be the case, even after post weld heat treatments.
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Soldagem de chapas grossas em aço baixa liga temperado e revenido ASTM A514 com aço carbono ASTM A36 pelo processo arame tubular / Welding of ASTM A514 quenched and tempered low alloy steel thick plates with ASTM A36 carbon steel by FCAW processFerrari, Marcello 09 December 2016 (has links)
Neste trabalho foram determinadas as condições para a soldagem de chapas grossas de aço carbono ASTM A36 com aço baixo-liga temperado e revenido ASTM A514 Grau Q empregando-se o processo arame tubular. Para tanto foram soldadas diversas peças de testes com o intuito de se avaliar as condições mais adequadas de preparação e soldagem de juntas dissimilares destes materiais. A preparação foi realizada por meio de corte térmico. A temperatura de preaquecimento foi determinada através de modelos matemáticos, pelas recomendações das normas AWS D1.1 e DIN EN 1011-2 sendo posteriormente avaliada por intermédio do teste de soldabilidade tipo CTS Controlled Thermal Severity. Os parâmetros de soldagem foram determinados a partir da qualificação de um procedimento de soldagem, conforme a norma AWS D1.1. Foram avaliadas as consequências do emprego do tratamento térmico de alívio de tensões após soldagem (TTAT), pelos testes de dureza Vickers e impacto Charpy. A caracterização microestrutural foi realizada por meio de microscopia óptica e microscopia eletrônica de varredura. A caracterização das superfícies oxicortadas evidenciou os efeitos da descarbonetação e também da carbonetação. A temperatura de pré-aquecimento de 160°C determinada por meio da metodologia recomendada pelas normas AWS D1.1 e DIN EN 1011-2 mostrou-se satisfatória nos testes de soldabilidade. Foi possível a qualificação do procedimento de soldagem (EPS) com requisitos de impacto na condição \"como soldado\", porém na condição \"após TTAT\", os baixos valores de tenacidade obtidos no metal de solda, inferiores a 27J, não permitiram a qualificação de uma EPS com requisitos de impacto. Foi observada a ausência de trincas intergranulares tanto na zona afetada pelo calor quanto no metal de base ASTM A514, porém foi revelada a presença de microfases frágeis no metal de solda na condição \"como soldado\", especificamente na região da raiz, intensificadas pelo efeito da diluição. O aumento do teor de carbono na raiz, a presença de microfases frágeis, a grande fração de grãos colunares e de ferrita proeutetóide combinados com a baixa fração de ferrita acicular no metal de solda contribuíram para os baixos valores de tenacidade encontrados na condição \"como soldado\". Após o TTAT observou-se uma queda acentuada da tenacidade, inferior a 27J, do metal de solda devido à fragilização provocada pela precipitação e coalescimento de carbonetos de ferro. / In this work it was determined the conditions for welding thick plate of ASTM A36 carbon steel with quenched and tempered low-alloy steel ASTM A514 Grade Q employing the Flux Cored Arc Welding (FCAW) process. For that several coupons of tests were welded in order to evaluate the most appropriate conditions for preparation and welding of these dissimilar materials. The preparation was carried out by means of thermal cutting. The preheat temperature was determined by mathematical models, the recommendations of standards AWS D1.1 and DIN EN 1011-2 being further evaluated using the CTS type weldability test - Controlled Thermal Severity. The welding parameters were determined by qualifying a welding procedure (WPS), according to AWS D1.1. The effects of post weld heat treatment (PWHT) were evaluated by Vickers hardness tests and Charpy. Microstructural characterization was performed by optical microscopy and scanning electron microscopy. The characterization of oxi-fuel cut surfaces showed the effects of decarburization and also carburization. The preheating temperature of 160 °C determined by calculation and the methodology recommended by the standards was satisfactory in weldability tests. It was possible qualification of welding procedure (WPS) with impact requirements in the condition \"as welded\" but the condition \"after PWHT\" low toughness values obtained in the weld metal, less than 27J, did not allow to qualify a WPS with toughness requirements. The absence of intergranular cracking was observed in both the heat affected zone as the base metal ASTM A514, but the presence of fragile microphase in the weld metal was revealed in the weld metal in the condition \"as welded\" specifically in the root region, intensified by the effect of dilution. The carbon increase at root, the presence of fragile microphase, the large fraction of columnar grains and proeutectoid ferrite combined with the low fraction of acicular ferrite in the weld metal contributed to the low toughness values found in the condition \"as welded \". After PWHT there was a sharp drop in toughness, less than 27J, in the weld metal due to embrittlement caused by precipitation and coarsening of iron carbides.
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Avaliação de propriedades mecânicas e caracterização microestrutural de juntas soldadas do aço ASTM 335 grau P91 submetidas a diversas condições ao tratamento térmico de alívio de tensões / Evaluation of mechanical properties and microstructural characterization of grade 91 steel welded joints subjected to several conditions to post weld heat treatment (PWHT)Teixeira, Marcos Antônio 23 September 2016 (has links)
Os aços Grau 91 vêm sendo amplamente utilizados como componentes para trabalhar em elevadas temperaturas nas indústrias de geração de energia, petroquímica e refinarias de petróleo em consequência da sua excelente resistência a fluência e corrosão em altas temperaturas. Apesar destas notáveis propriedades têm sido encontradas dificuldades na soldagem do aço Grau 91, visto que pode apresentar valores de dureza fora dos limites especificados e provocando redução de diversas propriedades mecânicas. Foram confeccionadas juntas tubulares do aço Grau 91, por meio de soldagem usando o processo TIG na raiz e o processo Eletrodo Revestido nas camadas de soldagem subsequentes. As juntas soldadas foram submetidas ao tratamento térmico póssoldagem (TTPS) a 760°C com diferentes tempos de patamar (1h, 4h e 8h) e posteriormente, as propriedades mecânicas foram analisadas para verificar o atendimento aos requisitos normativos, por meio da realização de ensaios de tração convencional e à quente (540°C), impacto Charpy, dureza Vickers e caracterização microestrutural. Os resultados mostraram que as propriedades mecânicas do aço Grau 91 sofreram alterações, como uma melhor resistência ao impacto e diminuição da dureza com o aumento do tempo de patamar de temperatura, indicando que é possível obter uma melhor combinação de resistência mecânica e tenacidade com o tempo de patamar maior do que 4 horas no TTPS nas condições utilizadas. / Grade 91 steels have been widely used as components to work at high temperatures in power generation plants, petrochemicals and oil refineries as a result of their excellent creep and corrosion resistance at high temperatures. Despite these remarkable properties, difficulties in welding Grade 91 have been encountered, as they may exhibit hardness values outside the specified limits and cause a reduction in various mechanical properties. Grade 91 tubular joints were made through welding by using the GTAW process at the root and the SMAW process in the subsequent welding layers. The welded joints were subjected to PWHT at 760°C with different tempering times (1h, 4h and 8h) and their mechanical properties were evaluated by performing conventional tensile, elevated-temperature tensile (540°C), Charpy V-notch impact toughness, Vickers hardness testing and microstructural characterization. Results indicated that mechanical properties of grade 91 steel change with increasing tempering time, and a better combination of strength and toughness can be reached with more than 4 hours of PWHT, under certain conditions.
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Avaliação de propriedades mecânicas e caracterização microestrutural de juntas soldadas do aço ASTM 335 grau P91 submetidas a diversas condições ao tratamento térmico de alívio de tensões / Evaluation of mechanical properties and microstructural characterization of grade 91 steel welded joints subjected to several conditions to post weld heat treatment (PWHT)Marcos Antônio Teixeira 23 September 2016 (has links)
Os aços Grau 91 vêm sendo amplamente utilizados como componentes para trabalhar em elevadas temperaturas nas indústrias de geração de energia, petroquímica e refinarias de petróleo em consequência da sua excelente resistência a fluência e corrosão em altas temperaturas. Apesar destas notáveis propriedades têm sido encontradas dificuldades na soldagem do aço Grau 91, visto que pode apresentar valores de dureza fora dos limites especificados e provocando redução de diversas propriedades mecânicas. Foram confeccionadas juntas tubulares do aço Grau 91, por meio de soldagem usando o processo TIG na raiz e o processo Eletrodo Revestido nas camadas de soldagem subsequentes. As juntas soldadas foram submetidas ao tratamento térmico póssoldagem (TTPS) a 760°C com diferentes tempos de patamar (1h, 4h e 8h) e posteriormente, as propriedades mecânicas foram analisadas para verificar o atendimento aos requisitos normativos, por meio da realização de ensaios de tração convencional e à quente (540°C), impacto Charpy, dureza Vickers e caracterização microestrutural. Os resultados mostraram que as propriedades mecânicas do aço Grau 91 sofreram alterações, como uma melhor resistência ao impacto e diminuição da dureza com o aumento do tempo de patamar de temperatura, indicando que é possível obter uma melhor combinação de resistência mecânica e tenacidade com o tempo de patamar maior do que 4 horas no TTPS nas condições utilizadas. / Grade 91 steels have been widely used as components to work at high temperatures in power generation plants, petrochemicals and oil refineries as a result of their excellent creep and corrosion resistance at high temperatures. Despite these remarkable properties, difficulties in welding Grade 91 have been encountered, as they may exhibit hardness values outside the specified limits and cause a reduction in various mechanical properties. Grade 91 tubular joints were made through welding by using the GTAW process at the root and the SMAW process in the subsequent welding layers. The welded joints were subjected to PWHT at 760°C with different tempering times (1h, 4h and 8h) and their mechanical properties were evaluated by performing conventional tensile, elevated-temperature tensile (540°C), Charpy V-notch impact toughness, Vickers hardness testing and microstructural characterization. Results indicated that mechanical properties of grade 91 steel change with increasing tempering time, and a better combination of strength and toughness can be reached with more than 4 hours of PWHT, under certain conditions.
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