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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

[en] EFFECT OF THE AUSTENITIZATION TEMPERATURE ON THE QUENCHING AND PARTITIONING PROCESS / [pt] EFEITO DA TEMPERATURA DE AUSTENITIZAÇÃO NO PROCESSO DE TÊMPERA E PARTIÇÃO

DANIEL MASSARI DE SOUZA COELHO 11 September 2008 (has links)
[pt] O processo de Têmpera e Partição (T&P) possibilita a produção de aços com frações controladas de austenita retida, a partir do enriquecimento da austenita pela partição de carbono da martensita sem a precipitação de carbonetos. A austenita retida proporciona o efeito TRIP (plasticidade induzida por transformação), que confere ao material uma deformação uniforme e uma melhor absorção de energia durante o impacto. Os aços produzidos por este processo atendem principalmente às necessidades da indústria automobilística, que busca aços com melhores propriedades para a diminuição de peso e aumento da segurança dos automóveis. Nesta dissertação, ligas de aço com diferentes composições e tamanhos de grão foram produzidos pelo processo de Têmpera e Partição e a fração de austenita retida foi medida por difração de raios-X. As ligas também foram caracterizadas por nanoindentação, microscopia ótica e microscopia eletrônica de varredura. As amostras estudadas foram produzidas com uma austenitização completa a 930°C, realizada para promover um aumento no tamanho de grão, e os resultados foram comparados com amostras estudadas anteriormente com temperatura de austenitização de 890°C. Os resultados obtidos indicaram um aumento da fração de austenita retida com o aumento do grão austenítico original. Estes resultados foram interpretados com base no modelo teórico desenvolvido para o processo T&P. / [en] The Quenching and Partitioning (Q&P) process allows the production of steels with controlled fractions of retained austenite from the enrichment of the austenite by carbon partitioning from the martensite without carbide precipitation. The retained austenite is responsible for the TRIP effect (transformation induced plasticity), which enhances the material behavior providing a uniform strain and a better energy absorption during impact. Steels produced by this process match the requirements of the automotive industry, which looks for weight reduction and safety improvements in cars. In the present dissertation, steels with different compositions and grain sizes were produced by the Quenching and Partition process and their retained austenite fraction was measured by x-ray diffraction. The steels were also characterized by nanoindentation, optical microscopy and scanning electron microscopy. The specimens studied were produced by a complete austenitization at 930°C, to promote an increase in the austenitic grain size, and the results were compared with previously studied specimens produced by a complete austenitization at 890°C. The experimental results indicate an increase of austenite fraction with an increase in grain size of the original austenite. These results were analyzed based on the theoretical model develop for the Q&P process.
82

Estudo da influência da temperatura nas propriedades magnéticas e na microestrutura nos ímãs permanentes à base de Pr-Fe-B-Nb-Co obtidos com hidrogênio / Study of the influence of the temperature in the magnetic properties and in microstructure in the permanent magnets Pr-Fe-B-Nb-Co based obtained by hydrogen

Silva, Suelanny Carvalho da 23 November 2007 (has links)
Pós magnéticos foram produzidos utilizando o processo de hidrogenação, desproporção, dessorção e recombinação (HDDR). A primeira parte deste trabalho envolveu o estudo do efeito da adição de Co na liga Pr14FebalCoxB6Nb0.1 (x= 0, 4, 8, 10, 12, 16) variando a de temperatura de dessorção/ recombinação de 800° a 900°C, com o objetivo de otimização do tratamento HDDR. A liga Pr14Fe80B6 foi utilizada como padrão. As ligas foram tratadas termicamente a 1100°C por 20 horas para eliminação do Fe- exixtente na liga em estado bruto de fusão. A temperatura de dessorção/ recombinação afetou a microestrutura e as propriedades magnéticas dos ímãs moldados com polímeros. A liga com baixa adição de cobalto (4 at.%) exigiu a temperatura de reação mais alta (880°C) entre os demais ímãs. As temperaturas ótimas para as ligas com 8 at.% Co e 10 at.% Co foram 840°C e 820°C, respectivamente. Ligas com altas concentrações de cobalto (12 at.% and 16 at.%) foram processadas a 840°C. A temperatura de dessorção/ recombinação que apresentou alta anisotropia nas ligas Pr14Fe80B6 e Pr14Fe79,9B6Nb0,1 foi de 820°C. O ímã que apresentou melhor remanência (862mT) foi processado com a liga Pr14Fe67,9Co12B6Nb0,1. Cada liga apresentou uma temperatura de reação otimizada e exibiu uma microestrutura particular, de acordo com a composição. A segunda parte deste trabalho envolveu a caracterização, dos pós HDDR de Pr14Fe80B6, que foram analisadas por difração de raios X com fonte síncrotron para a identificação e quantificação de fases cristalinas, e ainda para a determinação do tamanho médio de cristalitos da fase principal. A microscopia eletrônica de varredura (MEV) foi utilizada para revelar a morfologia dos pós HDDR. / Fine magnetic powders were produced using the hydrogenation disproportionation desorption and recombination (HDDR) process. The first stage in this work involved an investigation of the effect of the Co content and range of desorption/ recombination temperatures between 800 and 900°C with the purpose of optimizing the HDDR treatment for Pr14Fe80B6 and Pr14FebalCoxB6Nb0,1 (x= 0, 4, 8, 10, 12, 16) alloys. The cast alloys were annealed at 1100°C for 20 hours for homogenization. The processing temperature (desorption/ recombination) affected the microstructure and magnetic properties of the bonded magnets. The alloy with low cobalt content (4 at.%) required the highest reaction temperature (880°C) to yield anisotropic bonded magnets. The optimum temperature for alloys with 8 at.% Co and 10 at.% Co were 840°C and 820°C, respectively. Alloys with high cobalt content (12 at.% and 16 at.%) were processed at 840°C. The optimum desorption temperature for achieving high anisotropy for Pr14Fe80B6 and Pr14Fe79,9B6Nb0,1 was 820°C. The best remanence (862mT) was achieved with the Pr14Fe67,9B6Co12Nb0,1 magnet, processed at 840°C. Each alloy required an optimum reaction temperature and exhibited a particular microstructure according to the composition. The second stage of the work involved the characterization, for each temperature, of the Pr14Fe80B6 HDDR powder processed using X-ray diffraction analysis. The samples of the HDDR material were studied by synchrotron radiation powder diffraction using the Rietveld method for cell refinement, phase quantification and crystallite sizes determination. Scanning electron microscopy (SEM) has also been employed to reveal the morphology of the HDDR powder.
83

Studies of UHT-plant fouling by fresh, recombined and reconstituted whole milk : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Engineering

Srichantra, Arunee January 2008 (has links)
The objective of this study was to investigate the effects of preheat treatments on fouling by fresh whole milk (FWM), recombined whole milk (RCB) and reconstituted whole milk (Recon) in the high-temperature heater of indirect UHT plants. Various preheat treatments prior to evaporation during milk powder manufacture were applied to skim milk powder (SMP, 75 °C 2 s, 85 °C, 155 s and 95 °C, 155 s) and whole milk powder (WMP, 95 °C, 33 s). These preheat treatments were so-called “evaporator preheat treatments”. Skim milk powder (SMP) and whole milk powder (WMP) were derived from the same original batch of pasteurised FWM to remove the effects of the variation in milk composition between different milk batches. These SMPs were recombined with anhydrous milk fat and water to prepare RCB, and WMPs were reconstituted with water to prepare Recon. Then, (homogenized) FWM, RCB and Recon were subjected to various preheat treatments (75 °C, 11 s, 85 °C, 147 s and 95 °C, 147 s) prior to UHT processing. These preheat treatments were so-called “UHT preheat treatments”. Temperature difference (hot water inlet temperature – milk outlet temperature) was taken as a measure of the extent of fouling in the high-temperature heater. The slope of the linear regression of temperature difference versus time (for two hours of UHT processing) was taken as fouling rate (°C/h). Increasing both evaporator and UHT preheat treatments resulted in increasing fouling rate and total deposit weight for all three whole milk types for several milk batches. In the case of FWM, there was no reduction in fouling rate with increasing UHT preheat treatment whether FWM was homogenized then preheated, preheated then homogenized or not homogenized at all. These findings, which are wholly consistent and well replicated, are in apparent conflict with the results of most previous comparable studies. Possible reasons for this are explained. Further investigations of the effects of homogenization relating to the role of whey protein on the surface of the fat globules showed that whey protein associated with the membrane covering the surface of fat globules for homogenized then preheated FWM, RCB and Recon and that association increased with increasing heating process stage. The increasing association of whey protein with the milk fat globules membrane with increasing severity of heating process stage became faster when preheat treatment was more severe: the association of whey protein plateaued on intermediate temperature heating when the milks were preheated at 75°C, 11 s and on preheating when the milks were preheated at 95°C, 147 s. In the case of FWM, the thickness of the membrane covering the surface of fat globules for homogenized then preheated FWM, which increased with the severity of heating process stage, was greater than the thickness of the membrane in preheated then homogenized FWM. Preheating then homogenization resulted in the greater interfacial spreading of small molecules on the surface of fat globules, i.e. whey protein or small molecules from the disintegration of casein micelles during preheating. Possible basic mechanisms for UHT fouling in the high-temperature heater include: the reduction in the solubility of calcium phosphate and the deposition of protein as fat-bound protein and non-fat-bound protein. When non-fat-bound protein in milk plasma deposited, it could be a carrier for the deposition of mineral, such as, the precipitate of calcium phosphate in the casein micelles or the deposition of complexes between whey protein and casein micelles.
84

Studies of UHT-plant fouling by fresh, recombined and reconstituted whole milk : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Engineering

Srichantra, Arunee January 2008 (has links)
The objective of this study was to investigate the effects of preheat treatments on fouling by fresh whole milk (FWM), recombined whole milk (RCB) and reconstituted whole milk (Recon) in the high-temperature heater of indirect UHT plants. Various preheat treatments prior to evaporation during milk powder manufacture were applied to skim milk powder (SMP, 75 °C 2 s, 85 °C, 155 s and 95 °C, 155 s) and whole milk powder (WMP, 95 °C, 33 s). These preheat treatments were so-called “evaporator preheat treatments”. Skim milk powder (SMP) and whole milk powder (WMP) were derived from the same original batch of pasteurised FWM to remove the effects of the variation in milk composition between different milk batches. These SMPs were recombined with anhydrous milk fat and water to prepare RCB, and WMPs were reconstituted with water to prepare Recon. Then, (homogenized) FWM, RCB and Recon were subjected to various preheat treatments (75 °C, 11 s, 85 °C, 147 s and 95 °C, 147 s) prior to UHT processing. These preheat treatments were so-called “UHT preheat treatments”. Temperature difference (hot water inlet temperature – milk outlet temperature) was taken as a measure of the extent of fouling in the high-temperature heater. The slope of the linear regression of temperature difference versus time (for two hours of UHT processing) was taken as fouling rate (°C/h). Increasing both evaporator and UHT preheat treatments resulted in increasing fouling rate and total deposit weight for all three whole milk types for several milk batches. In the case of FWM, there was no reduction in fouling rate with increasing UHT preheat treatment whether FWM was homogenized then preheated, preheated then homogenized or not homogenized at all. These findings, which are wholly consistent and well replicated, are in apparent conflict with the results of most previous comparable studies. Possible reasons for this are explained. Further investigations of the effects of homogenization relating to the role of whey protein on the surface of the fat globules showed that whey protein associated with the membrane covering the surface of fat globules for homogenized then preheated FWM, RCB and Recon and that association increased with increasing heating process stage. The increasing association of whey protein with the milk fat globules membrane with increasing severity of heating process stage became faster when preheat treatment was more severe: the association of whey protein plateaued on intermediate temperature heating when the milks were preheated at 75°C, 11 s and on preheating when the milks were preheated at 95°C, 147 s. In the case of FWM, the thickness of the membrane covering the surface of fat globules for homogenized then preheated FWM, which increased with the severity of heating process stage, was greater than the thickness of the membrane in preheated then homogenized FWM. Preheating then homogenization resulted in the greater interfacial spreading of small molecules on the surface of fat globules, i.e. whey protein or small molecules from the disintegration of casein micelles during preheating. Possible basic mechanisms for UHT fouling in the high-temperature heater include: the reduction in the solubility of calcium phosphate and the deposition of protein as fat-bound protein and non-fat-bound protein. When non-fat-bound protein in milk plasma deposited, it could be a carrier for the deposition of mineral, such as, the precipitate of calcium phosphate in the casein micelles or the deposition of complexes between whey protein and casein micelles.
85

Studies of UHT-plant fouling by fresh, recombined and reconstituted whole milk : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Engineering

Srichantra, Arunee January 2008 (has links)
The objective of this study was to investigate the effects of preheat treatments on fouling by fresh whole milk (FWM), recombined whole milk (RCB) and reconstituted whole milk (Recon) in the high-temperature heater of indirect UHT plants. Various preheat treatments prior to evaporation during milk powder manufacture were applied to skim milk powder (SMP, 75 °C 2 s, 85 °C, 155 s and 95 °C, 155 s) and whole milk powder (WMP, 95 °C, 33 s). These preheat treatments were so-called “evaporator preheat treatments”. Skim milk powder (SMP) and whole milk powder (WMP) were derived from the same original batch of pasteurised FWM to remove the effects of the variation in milk composition between different milk batches. These SMPs were recombined with anhydrous milk fat and water to prepare RCB, and WMPs were reconstituted with water to prepare Recon. Then, (homogenized) FWM, RCB and Recon were subjected to various preheat treatments (75 °C, 11 s, 85 °C, 147 s and 95 °C, 147 s) prior to UHT processing. These preheat treatments were so-called “UHT preheat treatments”. Temperature difference (hot water inlet temperature – milk outlet temperature) was taken as a measure of the extent of fouling in the high-temperature heater. The slope of the linear regression of temperature difference versus time (for two hours of UHT processing) was taken as fouling rate (°C/h). Increasing both evaporator and UHT preheat treatments resulted in increasing fouling rate and total deposit weight for all three whole milk types for several milk batches. In the case of FWM, there was no reduction in fouling rate with increasing UHT preheat treatment whether FWM was homogenized then preheated, preheated then homogenized or not homogenized at all. These findings, which are wholly consistent and well replicated, are in apparent conflict with the results of most previous comparable studies. Possible reasons for this are explained. Further investigations of the effects of homogenization relating to the role of whey protein on the surface of the fat globules showed that whey protein associated with the membrane covering the surface of fat globules for homogenized then preheated FWM, RCB and Recon and that association increased with increasing heating process stage. The increasing association of whey protein with the milk fat globules membrane with increasing severity of heating process stage became faster when preheat treatment was more severe: the association of whey protein plateaued on intermediate temperature heating when the milks were preheated at 75°C, 11 s and on preheating when the milks were preheated at 95°C, 147 s. In the case of FWM, the thickness of the membrane covering the surface of fat globules for homogenized then preheated FWM, which increased with the severity of heating process stage, was greater than the thickness of the membrane in preheated then homogenized FWM. Preheating then homogenization resulted in the greater interfacial spreading of small molecules on the surface of fat globules, i.e. whey protein or small molecules from the disintegration of casein micelles during preheating. Possible basic mechanisms for UHT fouling in the high-temperature heater include: the reduction in the solubility of calcium phosphate and the deposition of protein as fat-bound protein and non-fat-bound protein. When non-fat-bound protein in milk plasma deposited, it could be a carrier for the deposition of mineral, such as, the precipitate of calcium phosphate in the casein micelles or the deposition of complexes between whey protein and casein micelles.
86

Effects of heat treatments on the safety and nutritional properties of whole grain barley

Boyd, Lindsey 11 January 2016 (has links)
Health claims for barley β-glucan (BG) have prompted the development of more food products using barley. Some new products do not use any form of heat treatment which could become an issue as barley has been found to have high microbial contamination. The aim of this research was to evaluate current commercial barley products for microbial and BG quality and determine the effects of different heat treatments on the safety and physicochemical properties of BG of whole grain barley. Three heat treatments (micronization, roasting and conditioning) were performed on 3 cultivars of barley (CDC Rattan, CDC McGwire and CDC Fibar). The microbial quality was measured with standard plate count (SPC), yeast and mould (MYC), and coliforms/E. coli. Only 4 of the 17 commercial barley products tested met acceptable microbial limits used in this study. All 3 heat treatments reduced SPC, MYC and coliforms to acceptable levels. BG was extracted using an in vitro digestion method to determine its viscosity, molecular weight (MW) and solubility. Heat-treated barley increased the BG viscosity and MW compared to the untreated barley. The effect of heat treatment on starch pasting, particle size and colour were also evaluated. Overall, heat treatments improved the safety and potential health benefits of whole grain barley. / February 2016
87

Membrana de alumina an?dica: comportamento da microestrutura e estudo das propriedades ?pticas ap?s tratamento t?rmico

Timoteo J?nior, Jos? Fl?vio 04 July 2012 (has links)
Made available in DSpace on 2014-12-17T14:07:09Z (GMT). No. of bitstreams: 1 JoseFTJ_TESE.pdf: 4834280 bytes, checksum: 1a618560296186081bd6c34117d226be (MD5) Previous issue date: 2012-07-04 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Thin commercial aluminum electrolytic and passed through reactions was obtained with anodic alumina membranes nanopores. These materials have applications in areas recognized electronic, biomedical, chemical and biological weapons, especially in obtaining nanostructures using these membranes as a substrate or template for processing nanowires, nanodots and nanofibers for applications noble. Previous studies showed that the membranes that have undergone heat treatment temperature to 1300? C underwent changes in morphology, crystal structure and optical properties. This aim, this thesis, a study of the heat treatment of porous anodic alumina membranes, in order to obtain and to characterize the behavior changes structures during the crystallization process of the membranes, at temperatures ranging between 300 and 1700? C. It was therefore necessary to mount a system formed by a tubular furnace resistive alumina tube and controlled environment, applying flux with special blend of Ag-87% and 13% N2, in which argon had the role of carrying out the oxygen nitrogen system and induce the closing of the pores during the densification of the membrane. The duration of heat treatment ranged from 60 to 15 minutes, at temperatures from 300 to 1700? C respectively. With the heat treatment occurred: a drastic reduction of porosity, grain growth and increased translucency of the membrane. For the characterization of the membranes were analyzed properties: Physical - thermogravimetric, X-ray diffraction, BET surface area; morphological - SEM, EDS through compositional and, optical absorbance, and transmittance in the UV-VIS, and FTIR. The results using the SEM showed that crystallization has occurred, densification and significant changes in membrane structure, as well as obtaining microtube, the BET analysis showed a decrease in specific surface area of the membranes has to 44.381 m2.g-1 to less than 1.8 m2.g-1 and in the analysis of transmittance and absorbance was found a value of 16.5% in the range of 800 nm, characteristic of the near infrared and FTIR have confirmed the molecular groups of the material. Thus, one can say that the membranes were mixed characteristics and properties which qualify for use in gas filtration system, as well as applications in the range of optical wavelength of the infra-red, and as a substrate of nanomaterials. This requires the continuation and deepening of additional study / L?minas delgadas de alum?nio comercial passaram por rea??es eletrol?ticas e obtiveram-se membranas de alumina an?dica com nanoporos. Estes materiais t?m reconhecidas aplica??es nas ?reas eletr?nicas, biom?dicas, qu?micas e biol?gicas, principalmente, na obten??o de nanoestruturas utilizando estas membranas como substrato ou molde para processamento de nanofios, nanopontos e nanofibras para aplica??es nobres. Estudos anteriores apontaram que as membranas que passaram por tratamentos t?rmicos at? a temperatura de 1300? C, sofreram altera??es na morfologia, na estrutura cristalina e nas propriedades ?pticas. O objetivo deste trabalho foi o estudo do tratamento t?rmico de membranas de alumina an?dica porosas, com o intuito de obter e caracterizar as altera??es de comportamento das estruturas, durante o processo de cristaliza??o das membranas, em temperaturas que variaram entre 300 e 1700? C. Assim, foi necess?rio montar um sistema formado por um forno resistivo tubular e tubo de alumina com ambiente controlado, aplicando fluxo com mistura especial de Ar-87% e N2-13%, no qual o arg?nio teve o papel de carrear o oxig?nio para fora do sistema e o nitrog?nio de induzir o fechamento dos poros, durante a densifica??o das membranas. A dura??o dos tratamentos t?rmicos variou de 60 a 15 minutos, para as temperaturas de 300 at? 1700? C respectivamente. Com o tratamento t?rmico ocorreu redu??o dr?stica da porosidade, crescimento do gr?o e aumento da translucidez da membrana. Para a caracteriza??o das membranas, foram feitas an?lises das propriedades: f?sica - termogravim?trica; difra??o de raios-X, ?rea superficial BET; morfol?gica - MEV, composicional atrav?s do EDS; e, ?ptica - transmit?ncia e absorb?ncia no UV-VIS e FTIR. Os resultados por meio do MEV mostraram que ocorreu cristaliza??o, densifica??o e mudan?as significativas na estrutura das membranas, bem como, a obten??o de microtubo; a an?lise de BET constatou uma diminui??o na ?rea superficial espec?fica das membranas que passou de 44,381m2.g-1, para menos de 1,8m2.g-1; na an?lise de transmit?ncia e absorb?ncia foi encontrado um valor de 16,5 % na faixa de 800nm, caracter?stico do infravermelho pr?ximo e no FTIR foram confirmadas os grupos moleculares do material. Assim, pode-se afirmar que as membranas apresentaram caracter?sticas mistas e propriedades que as qualificam para o uso em sistema de filtra??o de gases, bem como, de aplica??es ?ticas na faixa do comprimento de onda do Infravermelho, e como substrato de nanomateriais. Isto requer a continuidade e aprofundamento em estudos complementares
88

Caracterizacao microestrutural do aco maraging de grau 400 de resistencia mecanica ultra-elevada

PADIAL, ARMANDO G.F. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:46:42Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:09Z (GMT). No. of bitstreams: 1 07613.pdf: 5555459 bytes, checksum: 0047c9f052248797761d648268e841ba (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
89

Estudo morfologico e cinetico da nitretacao por plasma pulsado do aco inoxidavel martensitico AISI 420

PINEDO, CARLOS E. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:44:26Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:39Z (GMT). No. of bitstreams: 1 06912.pdf: 10380955 bytes, checksum: 3e22ae9dda613db66c72f121ed37b278 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
90

Desenvolvimento de pastilhas vítreas para revestimento a partir da reciclagem de vidros sódico-cálcicos. / Development of vitreous pastilles by recycling of sodic-calcic glasses.

VELOSO, Isis Tatiane de Barros Macêdo. 29 June 2018 (has links)
Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-06-29T14:16:18Z No. of bitstreams: 1 ISIS TATIANE DE BARROS MACÊDO VELOSO - TESE (PPGCEMat) 2016.pdf: 3573054 bytes, checksum: bfcbdc962777a12887f4d94980048582 (MD5) / Made available in DSpace on 2018-06-29T14:16:18Z (GMT). No. of bitstreams: 1 ISIS TATIANE DE BARROS MACÊDO VELOSO - TESE (PPGCEMat) 2016.pdf: 3573054 bytes, checksum: bfcbdc962777a12887f4d94980048582 (MD5) Previous issue date: 2016-06-30 / A reciclagem de vidros surge como alternativa ao impacto causado pelo seu descarte no meio ambiente, contribuindo para preservação dos recursos naturais, redução na emissão de gases e diminuição no volume dos aterros e lixões. O vidro pode ser infinitamente reciclado, sem que haja perda de massa ou de suas propriedades. Além disso, destaca-se pela sua beleza, por ser um dos poucos materiais capazes de refletir luz, cuja aplicação pode resultar em produtos de elevado apelo estético. Esta pesquisa tem como objetivo o desenvolvimento de pastilhas para revestimento pelo processo de reciclagem de resíduos de vidros sódico-cálcicos, a partir de estudos de tratamento térmico de fusão e recozimento. Inicialmente, os vidros foram separados por cor, triturados manualmente, distinguidos em diferentes granulometrias e acondicionados em moldes de concreto celular. Em seguida, foram submetidos a diferentes tratamentos térmicos, que resultaram na fusão e recozimento, este último processo para minimizar as tensões internas que fragilizam o vidro. Desta forma, buscou-se analisar a influência das granulometrias e dos tratamentos térmicos sobre os aspectos visuais das peças; os estudos dos materiais dos moldes e sua interação com o vidro, a desmoldabilidade e o acabamento das pastilhas; os equipamentos utilizados para a cominuição dos cacos de vidro. Como resultados, definiu-se o tratamento térmico quatro (TT4) para os vidros incolores e o tratamento térmico cinco (TT5) para os vidros coloridos (azul, âmbar, verde claro e verde escuro), em busca de obter peças de textura enrugada, aspecto vítreo e superfície brilhosa. Quanto ao tratamento térmico, as análises realizadas por microscopia óptica mostraram a eliminação das tensões internas que fragilizam o vidro, assim como o teste de impacto demonstrou uma maior resistência ao choque para amostras com recozimento, comprovando, assim, sua eficácia. Quanto à viabilidade de produção, os resultados demonstraram que as pastilhas são passíveis de serem confeccionadas pelo grupo CAVI, em escala artesanal, utilizando tecnologias e recursos acessíveis ao grupo, numa perspectiva de tecnologia social. / Glass recycling is an alternative to the impact caused by its disposal in environment, contributing to preservation of natural resources, reduction in gas emissions and decrease in volume of landfills and dumps. Glass can be recycled endlessly without any loss of mass or its properties. In addition, stands out for its beauty, for being one of few materials capable of reflecting light, the implementation of which may result in high aesthetic appeal products. This research aims to develop glass pastilles for coatings by recycling process of sodium-calcium glass residues, from heat treatment studies of melting and annealing. Initially, glasses were separated by color, manually grinded, distinguished into different granulometries and conditioned in cellular concrete molds. Then were subjected to different heat treatments, which resulted in melting and annealing, the latter process to minimize the internal tensions that weaken glass. Thus, it sought to analyze the influence of grain size and thermal treatments of visual aspects of the pieces; studies of materials of molds and their interaction with glass, demoldability and finish of the tablets; equipment used for comminution of the glass. As a result, it defined the heat treatment four (TT4) for colorless glass and heat treatment five (TT5) for tinted (blue, amber, light green, dark green) in seeking to obtain pieces of wrinkled texture, glassy and glossy surface. About heat treatment, the analysis performed by optical microscopy showed elimination of internal stresses which weaken the glass, and impact test showed a greater shock resistance for samples annealed, confirming thus its effectiveness. As for viability of production, results showed that pastilles are likely to be made by CAVI group, artisanal scale, using technologies and resources accessible to the group, in a perspective of social technology.

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