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The structure of the Grand Challenges Scholars Program (GCSP) of the Universidade Federal de Minas Gerais -UFMG, School of Engineering, linked to the National Academy of Engineering (NAE) former initiative, is presented. This academic program has an aspirational vision of educating professionals for facing the challenges of engineering in the twenty-first century. The approach is based on an integrative methodology, geared toward the formation of critical competencies, with a focus on solutions to global problems. It creates opportunities for cooperation, as well as develops multicultural and multidisciplinary competencies, social ability, and commitment. Currently, the courses at the UFMG School of Engineering are adapting to meet the new national guidelines for Engineering courses in Brazil, published in January 2019, and the GCSP is a pilot program, capable of transforming the methodology, the mentality, and the educational and technological tools it uses, into an alternative for all engineering courses at UFMG. The Program started its activities in the School of Engineering in 2020, despite the challenges and limitations imposed by the Covid-19 pandemic. The operational criteria and the internal organization were defined, and the Program was introduced to the students. The first initiatives of the Program - with broad access to engineering students and open to the participation of students from other areas - included the Call No.01/2020 - Covid-19 and the I Sustainability Workshop, held in 2021.

Metakaolinis the principal raw material utilized in the synthesis of geopolymers, although its ratio of silica and alumina contents is not ideal. Normally, the SiO2 content is adjusted with the use of silicates present in the activating solution. An eco-efficient alternative would be the use of glass waste as an additional source of silica.This work evaluates the efficiency of the alkaline activation of metakaolin, using potassium hydroxide and silicate, with and without the substitution of 12.5% of metakaolin by microparticles of glass. The efficiency of the alkaline activation was evaluated by X ray diffractometry, spectroscopy in the infrared region with the Fourier transform, nuclear magnetic resonance spectroscopy of 27Al and 29Si, specific mass and compressive strength. The results indicate the occurrence of geopolymerization with and without the use of glass waste. It was observed that the substitution of 12.5% favors the mechanical performance of the compounds at 28 days, with increases by 37% and 47% in the mechanical strength of the material with thermal curing and ambient temperature curing, respectively. Resumo O metacaulim é a principal matéria-prima utilizada na síntese de geopolímeros, embora a relação entre os teores de sílica e alumina não seja a ideal. Normalmente, o teor de SiO 2 é ajustado com o uso de silicatos presentes na solução ativadora. Uma opção ecoeficiente seria o uso de resíduos de vidro como fonte adicional de sílica. Este trabalho avalia a eficiência da ativação alcalina do metacaulim, utilizando hidróxido e silicato de potássio, com e sem substituição de 12,5% de metacaulim por micropartículas de vidro. A eficiência da ativação alcalina foi avaliada por difratometria de raios x, espectroscopia na região infravermelha com transformada de Fourier, espectroscopia de ressonância magnética nuclear do 27 Al e 29 Si, massa específica e resistência à compressão. Os resultados indicam a ocorrência de geopolimerização com e sem uso de resíduo de vidro. Observou-se que a substituição de 12,5% favorece o desempenho mecânico dos compósitos aos 28 dias, com aumentos de 37% e 47% da resistência mecânica do material com cura em estufa e na temperatura ambiente, respectivamente.

O conforto térmico do ambiente construído é um conteúdo fortemente relacionado com os elevados índices de consumo de energia elétrica decorrentes do uso de sistemas de condicionamento artificial de ar para se alcançar condições térmicas ambientais desejáveis. Esse consumo é consequéncia, principalmente, da inadequação dos elementos arquitetônicos aos aspectos climáticos locais e às demandas de conforto humano. O estudo das propriedades térmicas de materiais construtivos é, portanto, um relevante campo de estudo quando se deseja aliar conforto térmico e economia de energia. Com base em uma investigação interdisciplinar envolvendo Design, Arquitetura e Engenharia, este artigo mostra a importância da análise de conceitos como o da difusividade térmica de materiais construtivos no planejamento do conforto térmico de edificações.

The study of alkaline activated materials is very promising regarding the production of materials with high durability. The particle size and the content of reactive silica e alumina (amorphous) influence the performance of the geopolymer as well as the type of activator. In this study, geopolymers are produced using metakaolin precursors with similar chemical composition and different amorphities and particle sizes. KOH and K2SiO3 are used as activators, therefore, potassium solutions provide a lower viscosity of the pastes, better workability with a lower liquid to solids ratio and, consequently, better mechanical strength, denser and exhibited low porosity than sodium solutions. Produced precursors and pastes were characterized in the solid state by fluorescence X-ray spectroscopy, X-ray diffraction, infrared spectroscopy, nuclear magnetic resonance single pulse and nuclear magnetic resonance cross-polarization. The pastes were also evaluated for compressive strength, bulk density and water absorption. The results indicate that geopolymers can be obtained from metakaolins of incomplete calcination and with average grain diameter of 23.5 µm and 12.0 µm. Despite having similar bulk density and a slight difference in water absorption, the mechanical strength of the paste produced with coarser and more amorphous metakaolin at 28 days is 50 MPa, while the other paste reaches 22 MPa. The difference in mechanical strength is likely due to the greater extent of geopolymerization indicated by the NMR. The difference in the precursors and consequently in the pastes impacts on the expected durability.

Severe Plastic Deformation (SPD) leads to grain refinement and strengthening of metals. Among the many SPD processing methods, Multi-Directional Forging (MDF) is the only one where in-situ material stress–strain curves can be obtained. These are adequate only for specimens re-machined after each compression step, thus avoiding problems connected to specimen shape distortions; re-machining involves complex, expensive and time consuming procedures. This difficulty has been circumvented using confined plane strain compressions, where the strain path, however, differs from that in simple, unconfined free compression. A new processing method involving, for each processing step, an initial free simple compression followed by a confined compression (Multi-Directional Confined Forging – MDCF) is proposed, eliminating the specimen re-machining. Strengthening by MDF depends on strain amplitude; low strain amplitude MDF (LSA-MDF) leads to lower work hardening of the material than high strain amplitude MDF, as well as to limited softening and to an increase in the residual work hardening capacity of material previously deformed monotonically or in successive deformation steps with high strain amplitudes. This supplies a highly desired enhanced uniform elongation of the material after SPD. It is shown that Low Strain Amplitude Multi-Directional Confined Forging (LSA-MDCF) of aluminum leads to adequate stress–strain curves up to the contact of the specimen with the confining die walls, as well as to microstructures very similar to those obtained using free compressions with re-machined specimens. This processing route is simpler, faster and cheaper than LSA-MDF with re-machined samples, and thus emerges as a more practical MDF route.

Experiments were performed to analyze the microstructural evolution and mechanical behavior of commercial-purity copper (99.8%) processed by up to 48 cycles of multi-directional forging (MDF) using a low strain amplitude of ∼0.075 (total accumulated strain ε ≈ 10.8). Parabolic work-hardening concomitantly with increasing dislocation densities was observed up to ε ≈ 2, followed by a practically constant flow stress due to dynamic recovery. The average grain size was reduced from 30.5 μm in the annealed metal down to 4.1 μm for ε ≈ 7.2; the fraction of sub-micrometric grains reached ∼12% for ε ≈ 10.8. The microstructural changes were attributed to the fragmentation of the original grains by dislocation structures having low misorientation angles which gradually evolved into arrays of high-angle grain boundaries with increasing numbers of MDF cycles. The Cu samples subjected to 48 cycles of MDF displayed limited dynamic recrystallization, exhibiting basically dislocation cells and sub-grains with an average size of ∼0.6 μm. It is demonstrated that low strain amplitude MDF delays the kinetics of grain refinement in copper compared with MDF using higher strain amplitudes. Fil: Flausino, Paula Cibely Alves. Universidade Federal de Ouro Preto; Brasil. Universidade Federal de Minas Gerais; Brasil Fil: Nassif, Maria Elisa Landim. Universidade Federal de Minas Gerais; Brasil Fil: de Castro Bubani, Franco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Universidad Nacional de Cuyo; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Pereira, Pedro Henrique R.. Universidade Federal de Minas Gerais; Brasil Fil: Aguilar, Maria Teresa Paulino. Universidade Federal de Minas Gerais; Brasil Fil: Cetlin, Paulo Roberto. Universidade Federal de Minas Gerais; Brasil

Severe Plastic Deformation (SPD) leads to grain refinement and strengthening of metals. The most utilized SPD techniques are Equal Channel Angular Pressing (ECAP), High Pressure Torsion (HPT) and Multi-Axial Compression (MAC). Only MAC allows the determination of the stress–strain curves of the material during processing. Although ECAP and HPT processing has been analyzed in detail, there are few studies of MAC procedures and their consequences. It is shown that only specimens re-machined after each compression lead to adequate MAC stress–strain curves of the material, whose microstructures are not affected by re-machining.

Environmentally eco-efficient concrete is currently a popular choice of construction material. Reviewing relevant literature indicates that heating of cement paste can remove hydrating water, and that quartz sand of appropriate granulometry can act as a supplementary cementitious material; however, there have been virtually no reports on the reuse of these materials as alternative binders. This work evaluates the phases present in cementitious compounds produced with binders obtained by thermomechanically treating cement pastes with and without a 15% substitution of quartz sand powder (specific surface area 37.4 m²/g), referred to as RCQ and recycled cement RC, respectively. Testing included thermogravimetric analysis (performed with stripped gases), X-ray diffraction, and scanning electron microscopy with phase identification. The obtained data indicated RC cement paste possesses a predominantly ettringite microstructure, whereas the presence of calcium hydroxide and hydrated calcium silicate predominates in RCQ paste. Resumo Atualmente tem-se buscado a obtenção de concretos ecoeficientes por meio da reciclagem dos resíduos de concreto. Estudos da literatura mostram que o aquecimento da pasta pode remover a água de hidratação e que areia quartzosa pode atuar como material cimentício suplementar quando na granulometria adequada. Entretanto, praticamente inexistem relatos sobre reuso desses materiais como aglomerantes alternativos. Este trabalho avalia as fases presentes em compostos cimentícios confeccionados com aglomerante obtido do tratamento termomecânico de pastas com 15% de pó de areia quartzosa (RCQ) e sem substituição (RC) com superfície específica de 37.4 m²/g. Foram realizadas termogravimetrias com análise de gases desprendidos, difração de raios X e microscopia eletrônica de varredura com identificação de fases. Os dados obtidos mostram que a pasta RC possui microestrutura predominante de etringita enquanto na pasta RCQ predomina a presença de hidróxido de cálcio e silicato de cálcio hidratado.

Supplementary cementitious materials interact chemically and physically with cement, influencing the formation of hydrate compounds. Many authors have analyzed the filler and pozzolanic effect. However, few studies have explored the influence of these effects on hydration, properties in the fresh and hardened states, and durability parameters of cementitious composites separately. This study investigates the influence of the replacement of 20% of Portland cement for silica fume (SF) or a 20-µm medium diameter quartz powder (QP) on the properties of cementitious composites from the first hours of hydration to a few months of curing. The results indicate that SF is pozzolanic and that QP has no pozzolanic activity. The use of SF and QP reduces the released energy at early times to the control paste, indicating that these materials reduce the heat of hydration. The microstructure with fewer pores of SF compounds indicates that the pozzolanic reaction reduced pore size and binding capability, resulting in equivalent mechanical properties, reduced permeability and increased electrical resistance of the composites. SF and QP increase the carbonation depth of the composites. SF and QP composites are efficient in the inhibition of the alkali-aggregate reaction. The results indicate that, unlike the filler effect, the occurrence of pozzolanic reaction strongly influences electrical resistance, reducing the risk of corrosion of the reinforcement inserted in the concrete.

Severe plastic deformation (SPD) of metals leads to their strengthening and grain refinement, but to low uniform elongations. Low Strain Amplitude Multi Directional Forging (LSA-MDF) is an important method for increasing this low uniform elongation. The application of workpieces of SPD-processed materials requires that their distributions of mechanical properties, microstructures and deformation be as homogeneous as possible. Analyses of these distributions after LSA-MDF have not been found in the literature, and are presented in the current investigation utilizing microhardness measurements, optical and electronic microscopy and finite element simulations. LSA-MDF causes higher strains, mcrohardeness and structural distortions in the central regions of the specimens than at their edges and corners. In addition, LSA-MDF utilizing confined compressions seems to be the preferred processing route, due to its ease and to the more homogeneous microhardness, microstructure and strain distributions in relation to other experimental procedures.

O vidro soda-cal-silica e um material com alto potencial de reciclagem. No entanto, o seu beneficiamento gera microparticulas que ficam suspensas na agua utilizada para resfriamento das ferramentas. Esse residuo e inerte e, comumente, nao reaproveitado. Para seu descarte e feita a decantacao das microparticulas de vidro utilizando floculantes, sendo a lama produzida depositada em aterros sanitarios. De acordo com a literatura, essas microparticulas de vidro poderiam atuar como material cimenticio suplementar na producao de cimento Portland. Contudo, as informacoes sobre o desempenho termico desses materiais sao escassas. Neste estudo investiga-se a difusividade termica de argamassas para fins estruturais confeccionadas com cimento Portland e lama de vidro soda-cal-silica com caracteristicas pozolânicas. Foram produzidas argamassas com e sem substituicao do cimento por 10 e 20% de lama in natura e lama lavada para retirada do floculante. As argamassas foram caracterizadas quanto a resistencia mecânica e difusividade termica. Tambem, foram determinadas a massa especifica, a condutividade termica e o perfil de aquecimento das amostras, parâmetros necessarios para avaliar a difusividade termica. Os resultados indicam que a lama de vidro, com e sem floculante, poderia ser utilizada em substituicao ao cimento sem comprometer a resistencia mecânica devido as suas caracteristicas pozolânicas. Nas argamassas com 10% de lama sem floculante se observa um aumento de aproximadamente 8% na resistencia. Contudo, em todas as amostras com lama de vidro, lavada ou nao, observa-se uma diminuicao de 3 a 4% na massa especifica e de 17 a 18% na condutividade termica, indicando que a reacao pozolânica nao ocorreu em toda a sua extensao. A difusividade, determinada com auxilio da termografia infravermelha, apresenta resultados compativeis com a literatura e indica que o uso do residuo nao influencia significativamente a inercia termica das argamassas. Dessa forma, a lama de vidro em substituicao a 10% e 20% de cimento Portland poderia ser utilizada em argamassas estruturais sem comprometer o desempenho termico do sistema, alem de contribuir com o meio ambiente ao dar destino adequado ao residuo e reduzir a retirada de materias primas para a producao de cimento. Palavras-chave: lama de vidro soda-cal-silica; difusividade termica; termografia infravermelha.

The manufacture of Portland cement used in the production of concrete emits large amounts of CO2into the atmosphere, contributing to the increase of the greenhouse effect. The environmental impact generated by the mineral exploration activity is a problem of easy verification, especially in open pit mines. The present work evaluated the possibility of using iron ore tailing as an addition to the partial replacement of the cement in mortars. The iron ore tailings were processed by drying in oven (48h at 105oC) and milling in a planetary mill (10min at 300RPM), obtaining medium grain size of 14,13 μm. For the characterization, laser granulometry, X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential thermal and thermogravimetric analysis (DTA / TGA) were performed. The sample is composed predominantly by quartz, hematite, goethite and gibbsite. After the characterization, the waste was used in the preparation of test specimens, with 10, 20 and 30% weight substitution of the cement. The composites were submitted to compression tests, with ages of 3, 7 and 28 days, using a strength rate of 0,25MPa/s. The mortars with 10, 20 and 30% of substitution presented resistance of 41.65, 36.26 and 31.64 MPa, being able to be characterized as category of Portland cement of resistance 40, 32 and 25 respectively. Considering the reduction of cement in the mortars produced, the results of compressive strength were relevant for the substitutions. The cements produced with the substitutions according to the Brazilian standards under the mechanical aspect can be classified as Portland cement.

Pozzolans are materials that when milled are able to react with the cement, forming compounds with binder properties. Seeking to reduce costs and improve Portland cement performance, the cement industry has used mineral additions such as pozzolans, partially replacing clinker in Portland cement. Sericitic Phyllite is a metamorphic rock, considered sterile by iron mining. It is extracted from the pit to enable the extraction of iron ore and is disposed in sterile piles, representing an environmental liability. The present work evaluated the possibility of the Sericitic Phyllite acquires pozzolanic properties from thermal treatment, to be used as mineral addition in the partial substitution of Portland cement in mortars. The material was processed by milling in its natural moisture of 8% using a high performance planetary mill, and calcination in an electric resistance furnace at different temperatures (350, 550 and 850oC) for thirty minutes each. It was characterized by laser granulometry, X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential thermal and thermogravimetric analysis (DTA/TGA). After characterization, specimens were prepared with 25% substitution by weight of the Portland cement by the Sericitic Phyllite. The calcined material in 350, 550 and 850oC reached, respectively, 70%, 76% and 82% of the resistance of the control mortar. The results indicate the feasibility of using the Sericitic Phyllite as mineral addition in Portland cements as the mortars with the calcined material in all temperatures reached 32MPa.

Low strain amplitude multi-axial compression (LSA-MAC) increases the work hardening capacity and uniform ductility of Aluminum after Severe Plastic Deformation (SPD) through Equal Channel Angular Pressing (ECAP). The mechanisms associated with this processing after ECAP are analyzed. LSA-MAC after 1 ECAP pass in Aluminum softens the material and is connected to the stabilization of the dislocation structures induced by ECAP into a configuration displaying an increased fraction of High Angle Grain Boundaries (HAGB). This occurs for a lower total imposed strain than that through a sequence of high strain ECAP passes or high strain amplitude multi-axial compression (HAS-MAC). Fil: de Faria, Cleber Granato. Universidade Federal de Minas Gerais; Brasil Fil: Silva Almeida, Natanael Geraldo e. Universidade Federal de Minas Gerais; Brasil Fil: de Castro Bubani, Franco. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo; Argentina Fil: Balzuweit, Karla. Universidade Federal de Minas Gerais; Brasil Fil: Aguilar, Maria Teresa Paulino. Universidade Federal de Minas Gerais; Brasil Fil: Cetlin, Paulo Roberto. Universidade Federal de Minas Gerais; Brasil

The global production capacity of corrugated cardboard used in packaging increased by 3.5% per year in the last decade. These packages have limited life span and, after use, contribute for increasing the waste stream on the planet. An interesting alternative for their reuse is the manufacture of unconventional furniture and objects. Nevertheless, there are few studies addressing the performance of cardboard for their application in furniture products. In this study we characterized corrugated cardboard by scanning electron microscopy, energy dispersive spectroscopy. X-ray diffraction, determination of the basic weight of paper (grammage), resistance to burst, column compression and uniaxial compression of test samples manufactured with a specific geometry. Results indicate that cardboard can be a material of great feasibility and workability to be used in furniture design.

Waste from scrap tires is one of the most environmentally harmful waste since it leads to significant soil and air pollution. This work investigates the effect of recycled rubber particles incorporation into cementitious composites modified with epoxy polymer. A Design of Experiment (DoE) was conducted to identify the effect of epoxy polymer inclusion (35 and 50 wt%), rubber inclusion (10, 15 and 20 wt%) and rubber particle size (coarse and fine particles) factors on the bulk density, mechanical strength and stiffness of the composites. Third-order interaction effects were obtained, except for density which was affected by two second-order interactions. Larger epoxy polymer and rubber amounts decreased the bulk density of the composites. Epoxy polymer contributes to cement hydration, even without water content. Higher incorporation of coarse rubber particles leads to reduced mechanical performance. In general, lower amounts of epoxy polymer and finer rubber aggregates provide superior mechanical strength and modulus. The use of epoxy polymer also enhances the adhesion between cement and rubber aggregates. This rubber polymer-cementitious composite achieved promising results, being a feasible alternative to reuse end-of-life rubber tyres into structural applications.

This paper analyzes the effects of crystalline and amorphous silica additions (15 wt%) on the geopolymers structures. The precursors were metakaolin with or without replacement of 15 wt% by an amorphous (rice husk ash) or crystalline (finely ground quartz sand) silica source. The reactivity of the raw materials (pozzolanicity index) was evaluated by the Modified Chapelle test and thermal analysis. Transmission electron microscopy (TEM), Infrared spectroscopy, and X-ray diffraction with Rietveld refinement were used to characterize the geopolymers. Both metakaolin and rice husk ash showed high pozzolanicity, whereas the ground quartz sand was a non-pozzolanic material. TEM analysis detected the formation of an amorphous binder (N-A-S-H gel) in the pure metakaolin-based geopolymer. The addition of the reactive rice husk ash raised the content of the Si-O-Si bond in the geopolymer binder. Using the ground quartz sand reduced the estimated amorphous content of the geopolymers. However, the samples displayed similar compressive strengths (from 52 to 56 MPa at 28 days), indicating that the chemical reactivities of the raw materials had little effect on the geopolymerization for silica addition of 15 wt%. It could be attributed to a non-reacted fraction of rice husk ash in such conditions. Still, the filler effect provided by the unreacted amorphous silica and quartz particles could contribute to the geopolymer properties.

Ready-mixed concrete manufacturing consumes a lot of cement and generates millions of m3 of concrete sludge waste (CSW). It is known that CSW is heterogeneous and has different chemical and physical properties. This paper evaluates the influence of fine CSW fractions on the properties of structural mortars by partially replacing cement with fine fractions of concrete sludge waste. CSW samples were collected from three different concrete batching plants (CBPs) and 25% of cement used in concrete production was replaced by fine fractions of sludge – maintaining the water/fines ratio and no additives were used. The results showed that the variation in characteristics of the three CSWs influenced the properties of the mortars produced. Results at hardened state, with cement replacement by fine sludge waste, were close to those recorded for mortars composed with the addition of limestone filler – values were within the ranges set by the standard for composite cement with filler. The results became closer as calcite content increased in the sludge samples.

Different studies investigate the use of waste glass in Portland cement compounds, either as aggregates or as supplementary cementitious materials. Nevertheless, it seems that there is no consensus about the influence of particle color and size on the behavior of the compounds. This study addresses the influence of cement replacement by 10 and 20% of the colorless and amber soda-lime glass particles sized around 9.5 μm on the performance of Portland cement mortars. Results revealed that the partial replacement of cement could contribute to the production of durable mortars in relation to the inhibition of the alkali-aggregate reaction. This effect was more marked with 20% replacement using amber glass. Samples containing glass microparticles were more resistant to corrosion, in particular those made of colorless glass. The use of colorless and amber glass microparticles promoted a reduction in wear resistance.

The effect of high temperature on the mechanical properties of concrete reinforced by steel fibers with various aspect ratios has been investigated in this study. Concrete specimens were fabricated from four different concrete mixtures and cured for 28 days. After curing and natural drying, the specimens were annealed at a temperature of 500 &deg, C for 3 h in an electric furnace. The compressive and tensile strengths as well as the elastic moduli of the produced specimens were determined. It was found that the mechanical properties (especially flexural toughness) of steel fiber-reinforced concrete were less affected by high temperature as compared to those of control concrete specimens. The flexural tensile strength of fiber-reinforced concrete measured after high-temperature treatment was almost equal to the value obtained for the reference concrete specimen at room temperature. It should be noted that the addition of steel fibers to concrete preserves its mechanical properties after exposure to a temperature of 500 &deg, C due to fire for a period of up to 3 h, and thus is able to improve its high-temperature structural stability. The test results of this study indicate that the use of steel fibers in concrete-based materials significantly enhances their fire and hear-resistant characteristics.

Resumo Sistemas alimentares têm sido, tradicionalmente, objeto de estudo das ciências sociais e agrícolas. Mais recentemente, a pesquisa em Design vem desenvolvendo estratégias que buscam compreender as relações entre a sustentabilidade e o sistema alimentar. Não como meio de produção de uma commodity tangível a ser comercializada, mas como resultado de um sistema sociotécnico intangível, que pode ser projetado para melhoria da qualidade de vida. Este trabalho tem como objetivo analisar as interseções entre os conceitos de Sistema Produto-Serviço (PSS) em Comunidades que Sustentam a Agricultura (CSA). Nesse contexto, são analisadas duas CSAs como alternativas capazes de transformar positivamente a forma com a sociedade produz, distribui e comercializa os alimentos. Também se discute as limitações do estudo e o papel do design no desenvolvimento de modelos de CSAs mais eficientes e sustentáveis no que se refere ao sistema alimentar como um todo. Os resultados permitem contextualizar o funcionamento das CSAs estudadas e identificar os particulares desafios que possam ser superados utilizando-se processos e habilidades do PSS. Abstract Food systems have traditionally been the subject of social and agricultural sciences research. More recently, design research has been developing strategies that help understand the intersections between sustainability and the food system. It is not seen as a means of producing a tangible commodity to be marketed but as a result of an intangible sociotechnical system, which can be designed to improve life quality. This work aims to analyze the intersections between the concepts of Product-Service System (PSS) in Communities that Support Agriculture (CSA). In this context, two CSAs are analyzed as alternatives capable of positively transforming the way society produces, distributes and markets food. The limitations of this study and the role of design, in the development of more efficient and sustainable CSA models for the food system, are also discussed. The results allow to contextualize the functioning of the CSAs studied and to identify the particular challenges that can be overcome using PSS’ processes and skills.

Work hardening caused by Severe Plastic Deformation (SPD) strengthens ductile metals remarkably but practically annihilates their further work hardening during monotonic post-SPD deformation. Low Strain Amplitude Multi-Directional Forging (LSA-MDF) after one Equal Channel Angular Pressing (ECAP) pass of aluminum causes limited softening and regenerates its work hardening capacity. The full development of an SPD condition in aluminum demands an initial deformation higher than that associated with one ECAP pass. The present research analyzes the application of LSA-MDF to aluminum after 4 ECAP passes. A regeneration of the work hardening capacity of the material was observed. In addition, LSA-MDF caused an increased fraction of High Angle Grain Boundaries (HAGBs) in the material and a decrease in the presence of distorted grains displaying internal dislocation structures.

Experiments were performed to examine the flow behavior and microstructural evolution in a Zn–Al–Cu–Mg alloy processed by up to 23 cycles of multi-directional forging (MDF). After a total strain (e) of ~20.7 the grain sizes in the primary η-Zn, eutectic and eutectoid components were reduced to ~0.25, 0.4 and 0.3 μm, respectively. The metal exhibits profuse shear banding and twinning and undergoes work hardening in the 1st MDF cycle. Further straining up to e ≈ 7 promotes significant grain refinement together with strain softening due to occurrence of grain boundary sliding. Afterwards, the plastic flow occurs under a constant stress and flow softening is again prevalent for e > 12. The individual components in the Zn–Al hypoeutectic alloy display different kinetics of hardening and grain refinement such that the microstructural changes are first observed in the primary η-Zn areas and subsequently in the eutectoid and eutectic domains. Based on the average hardness in each component, the rule of mixtures was used to estimate the overall material strength after MDF. Although the results show similar trends, it is revealed that the rule of mixtures overestimates the flow stresses compared with the in-situ stress-strain curve. This undermines the hypothesis of iso-strain and suggests that deformation concentrates in the weaker areas in the flow softening stages of MDF processing.