cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14321587.v1
title: Effect of zinc substitution by nickel on solids with hydrotalcite type structure

description: ABSTRACT Hydrotalcites can be used for different applications due to their chemical properties and to give rise to solids with high specific surface area, good thermal stability, high dispersion and basic character. These characteristics have led to the fact that these materials have received much attention and application in areas such as the removal of contaminants and the synthesis of catalysts. This study evaluated the effect of zinc substitution by nickel on zinc-aluminum hydrotalcites, which have shown activity for the catalytic depolymerization of poly(ethylene terephthalate). The hydrotalcite type structure was observed in all materials, noting that the increase of zinc leads to higher values of a parameter of the orthorhombic cells of the hydrotalcites. The decrease of the c parameter led to a greater interaction CO32-‧ ‧ ‧ OH in the interlaminar space. Solids with higher zinc content collapsed at lower temperatures, contrary to that induced by nickel. The calcined solids contain the ZnO, NiO y g-Al2O3 phases, whose presence depends on the metals present. The results suggest the presence of large particles with high crystallinity of the ZnO phase, whereas the broad peaks of NiO suggest the existence of small particles of this phase, whose crystallinity is affected by the presence of Zn2+ and Al3+ in the cubic lattice of NiO. Materials containing two metals presented isotherms characteristic of predominantly macroporous solids. In relation to the materials with three metals, the structures are mesoporous and with high specific surface area, observing that the solid Zn0,44Ni0,22Al0,33 contains slit-shaped pores, while the solids Zn0,33Ni0,33Al0,33 and Ni0,44Zn0,22Al0,33 presented typical isotherms of materials with narrow pores in the form of capillaries.
DOI: 10.6084/m9.figshare.14321589.v1
title: Microstructural aspects and mechanical behavior of hardfacing deposited by FCAW

description: ABSTRACT Several sorts of hardfacings has been used as a method of combating wear to increase equipment life cycle, reduce costs with maintenance stops, parts recovery and replacement. This work evaluates the incidence of cracking, microstructural characteristics and the mechanical behavior of FeCrC and FeCrC + Nb hardfacing alloys, deposited by self-shielded flux-cored arc welding (FCAW-S) process on SAE 1020 steel sheets. Single layer and double layer coatings were produced for both alloys in two interpass temperatures conditions, at room temperature and preheat of 250º. By liquid penetrant inspection, a lower incidence of cracks was observed to FeCrC + Nb alloy. The microstructures of all FeCrC alloy coatings presented large primary M7C3 carbides in a hexagonal and needle-shaped morphology on a matrix of a eutectic mixture of austenite and carbides. For FeCrC+Nb alloy single layer coatings, a microstructure with large niobium carbides (NbC) and few primary M7C3 carbides, both being surrounded by eutectic of austenite and carbides. However, for FeCrC+Nb alloy double layer coatings, microstructures indicate NbC carbides along with large and frequent M7C3 carbides, most of them in a needle-shape morphology and a few in a hexagonal shape, being surrounded by a eutectic mixture of austenite and thin M7C3 carbides. Microhardness was superior for FeCrC alloy, due to the predominance and morphology of the primary M7C3 carbides shown and the refinement promoted by Nb.
DOI: 10.6084/m9.figshare.14321589
title: Microstructural aspects and mechanical behavior of hardfacing deposited by FCAW

description: ABSTRACT Several sorts of hardfacings has been used as a method of combating wear to increase equipment life cycle, reduce costs with maintenance stops, parts recovery and replacement. This work evaluates the incidence of cracking, microstructural characteristics and the mechanical behavior of FeCrC and FeCrC + Nb hardfacing alloys, deposited by self-shielded flux-cored arc welding (FCAW-S) process on SAE 1020 steel sheets. Single layer and double layer coatings were produced for both alloys in two interpass temperatures conditions, at room temperature and preheat of 250º. By liquid penetrant inspection, a lower incidence of cracks was observed to FeCrC + Nb alloy. The microstructures of all FeCrC alloy coatings presented large primary M7C3 carbides in a hexagonal and needle-shaped morphology on a matrix of a eutectic mixture of austenite and carbides. For FeCrC+Nb alloy single layer coatings, a microstructure with large niobium carbides (NbC) and few primary M7C3 carbides, both being surrounded by eutectic of austenite and carbides. However, for FeCrC+Nb alloy double layer coatings, microstructures indicate NbC carbides along with large and frequent M7C3 carbides, most of them in a needle-shape morphology and a few in a hexagonal shape, being surrounded by a eutectic mixture of austenite and thin M7C3 carbides. Microhardness was superior for FeCrC alloy, due to the predominance and morphology of the primary M7C3 carbides shown and the refinement promoted by Nb.
DOI: 10.6084/m9.figshare.14321590
title: Forecast model for dephosphorization process of ferromanganese steels using artificial neural networks

description: ABSTRACT One of the main problems affecting the quality of steel products is the existence of contaminants in alloy steel, being phosphorus (P) a major contamination element interfering with the steelmaking process. The increased P concentration levels can severely affect physical integrity of steel bonds, thus threatening the quality of the final product. The dephosphorization process of Ferromanganese consists by carbothermic reaction that involves the control of the manganese volatilization and reduction of manganese oxide in injection of oxygen. Therefore, we propose to forecast model for dephosphorization process of Ferromanganese steels in a steelmaker industry, that allows estimating the phosphorus concentration levels at the final refining process. We chose the artificial neural network models because it is computational models inspired in the human nervous system and an architecture of neural network with the Levenberg-Marquadt algorithm and Kolmogorov theorem for improving the estimation technique. The developed model presented excellent performance with a percentage error of 0.09%. Based on this created estimation model it is possible to estimate the impact of certain P concentration levels in FeMnMC beforehand, with a considerable amount of reliability.
DOI: 10.6084/m9.figshare.14321592
title: Similar and dissimilar welding effect on the mechanical properties of 5383 H34, 5754 H34 and 6005 T6 aluminum alloys

description: ABSTRACT Aluminum alloys are not covered by their specific weight. Each class of aluminum alloy presents a set of properties that are favorable to a given function in the same product, just as the alloys may be present in the same vehicle. However, it is necessary to know the changes in the mechanical properties that occur with the union process of these aluminum alloys. The objective of this study was to evaluate the mechanical and morphological properties of alloys 5383 H34, 5754 H34 and 6005 T6 similarly welded and dissimilar by the MIG process. Six combinations of these alloys were characterized by mechanical tensile, folding and Vickers micro-hardness tests, as well as scanning electron microscopy (SEM) and optical microscopy (OM). Among the results obtained, a decrease in tensile strength was observed for all welded alloys. In addition, the microhardness was affected in the melt line, in the weld bead and in the HAZ (heat affected zone). The main causes of the reduction of the mechanical resistance of the welded alloys were the grain growth and the precipitate dissolution. The data obtained in this study contribute in a very positive way to the development and dimensioning of new projects and technologies involving aluminum alloys.
DOI: 10.6084/m9.figshare.14321593
title: Evaluation of the effect of plastic deformation on the microstructure, hardness and magnetic properties of AISI type 316L stainless steel

description: ABSTRACT AISI 316L steel is widely used as a low cost biomaterial in prostheses and surgical equipment, among other applications. These applications are due to their good corrosion resistance in the presence of environment containing body fluids. Although this steel has the mentioned characteristics, it may be compromised with the formation of alpha prime martensite (magnetic phase) induced by plastic deformation. In this case, the present work aimed to investigate the cold rolling effects on the martensitic phase formation. For that, three different deformations were performed. The plate as received and the deformed samples were subjected to ferritoscopy, Vickers microhardness and microstructural analysis by scanning electron microscopy, SEM. It was observed that in cold deformed samples there was the magnetic phase appearance (probably alpha prime martensite) and microhardness increase, due to the hardening and the deformation induced phases presence.
DOI: 10.6084/m9.figshare.14321593.v1
title: Evaluation of the effect of plastic deformation on the microstructure, hardness and magnetic properties of AISI type 316L stainless steel

description: ABSTRACT AISI 316L steel is widely used as a low cost biomaterial in prostheses and surgical equipment, among other applications. These applications are due to their good corrosion resistance in the presence of environment containing body fluids. Although this steel has the mentioned characteristics, it may be compromised with the formation of alpha prime martensite (magnetic phase) induced by plastic deformation. In this case, the present work aimed to investigate the cold rolling effects on the martensitic phase formation. For that, three different deformations were performed. The plate as received and the deformed samples were subjected to ferritoscopy, Vickers microhardness and microstructural analysis by scanning electron microscopy, SEM. It was observed that in cold deformed samples there was the magnetic phase appearance (probably alpha prime martensite) and microhardness increase, due to the hardening and the deformation induced phases presence.
DOI: 10.6084/m9.figshare.14321596
title: Study of X-ray diffraction profiles of a Ti-13Ta-3Sn alloy obtained by mechanical alloying

description: ABSTRACT The Ti-β alloys have become highly demanded in industry, due to their good physical and chemical characteristics. In the present work, a Ti-13Ta-3Sn (%at) alloy was synthesized using mechanical alloying (MA) between the times of 2 and 100h. The alloys were characterized by X-ray diffraction (XRD) and analyzed by the Rietveld method with the MAUD software. The microstructural changes and the evolution of the Ti-α and Ti-β phases were characterized. Identifying the presence of a new metastable fcc phase and the synthesis of an alloy with 79.80%wt of Ti-β phase, both alloys with nanometric crystallite size.
DOI: 10.6084/m9.figshare.14321596.v1
title: Study of X-ray diffraction profiles of a Ti-13Ta-3Sn alloy obtained by mechanical alloying

description: ABSTRACT The Ti-β alloys have become highly demanded in industry, due to their good physical and chemical characteristics. In the present work, a Ti-13Ta-3Sn (%at) alloy was synthesized using mechanical alloying (MA) between the times of 2 and 100h. The alloys were characterized by X-ray diffraction (XRD) and analyzed by the Rietveld method with the MAUD software. The microstructural changes and the evolution of the Ti-α and Ti-β phases were characterized. Identifying the presence of a new metastable fcc phase and the synthesis of an alloy with 79.80%wt of Ti-β phase, both alloys with nanometric crystallite size.
DOI: 10.6084/m9.figshare.14321598
title: The Effects of Pin Offset for FSW of Dissimilar Materials: A Study for AA 7075 – AA 6013

description: ABSTRACT The trend in welding of dissimilar aluminum alloys oriented to new application techniques to increase the functionality and perform the welding procedure without any problem in the welded joints. The pin profile and process parameters determined for the friction stir welding greatly affect the weldability and strength of the welded joints. In addition, it is also considered that the pin offset is also an effective factor on the strength and microstructure of welded joints. In the present study, aluminum alloys AA 6013–T6 and AA 7075–T651 were welded with the FSW process applying pin offset technique. The changes in the mechanical and microstructural properties were investigated. The onion ring structure was observed in all of microstructure of weld stir zone. Except the welded joint fabricated with the tool rotational speed of 400 rpm for both without pin offset and with offset to retreating side, all the welded joints were fractured at the base metal region and heat affected zone in AA 6013 alloy. The welded joints fabricated with the tool rotational speed of 400 rpm consisted of small and large cavity-type defects. Although defects were found to occur in the welded joints, none of the welded joints were fractured at the SZ during the tensile and bending tests. The ultimate tensile strength and elongation at rupture of the dissimilar FS welded joints were ranged between 164 MPa and 179 MPa, 6.5 and 7.6%, respectively. These defects were found to affect the ductility feature of the welded joints. The pin offset direction was found to affect the volume of parent materials in the stir zone. Hence, the material volume in the onion rings changes and, the hardness distribution is also affected by the changes in the material volume.
DOI: 10.6084/m9.figshare.14321598.v1
title: The Effects of Pin Offset for FSW of Dissimilar Materials: A Study for AA 7075 – AA 6013

description: ABSTRACT The trend in welding of dissimilar aluminum alloys oriented to new application techniques to increase the functionality and perform the welding procedure without any problem in the welded joints. The pin profile and process parameters determined for the friction stir welding greatly affect the weldability and strength of the welded joints. In addition, it is also considered that the pin offset is also an effective factor on the strength and microstructure of welded joints. In the present study, aluminum alloys AA 6013–T6 and AA 7075–T651 were welded with the FSW process applying pin offset technique. The changes in the mechanical and microstructural properties were investigated. The onion ring structure was observed in all of microstructure of weld stir zone. Except the welded joint fabricated with the tool rotational speed of 400 rpm for both without pin offset and with offset to retreating side, all the welded joints were fractured at the base metal region and heat affected zone in AA 6013 alloy. The welded joints fabricated with the tool rotational speed of 400 rpm consisted of small and large cavity-type defects. Although defects were found to occur in the welded joints, none of the welded joints were fractured at the SZ during the tensile and bending tests. The ultimate tensile strength and elongation at rupture of the dissimilar FS welded joints were ranged between 164 MPa and 179 MPa, 6.5 and 7.6%, respectively. These defects were found to affect the ductility feature of the welded joints. The pin offset direction was found to affect the volume of parent materials in the stir zone. Hence, the material volume in the onion rings changes and, the hardness distribution is also affected by the changes in the material volume.
DOI: 10.6084/m9.figshare.14321599.v1
title: Variables influence on splitting tensile and unconfined compressive strength of two sedimentary stabilized-cement soils

description: ABSTRACT This paper evaluates the development of splitting tensile strength (qt) and unconfined compressive strength (qu) of two soils artificially cemented over 28 days. For this, two silty soils (yellow and purple) characteristics of the Guabirotuba Formation of Curitiba/Brazil were stabilized with initial high strength cement with percentages of 3, 5, 7 and 9% in reference to the dry mass of the soils. Specimens with 50 mm diameter and 100 mm high (volume of 196,35 cm3) were molded with the different cement contents (C), different molding dry unit weights (γd), and molding moisture (ω) constant at 23% and subjected to tests of unconfined compression and splitting tensile. The ratio of voids/lime represented by the porosity/volumetric cement content ratio (η/Civ) was used to evaluate the development of qu and qt in addition to variables such as C, η and γd. The results show an increase of the mechanical resistance with the increase of the cement content and with the decrease of the voids (i.e., higher specific dry weight and lower η). A dosing equation for qu and qt of the soils studied and mixed with cement was developed using the η/Civ ratio adjusted to an exponent 0,44 to make η/Civ-qu qt variation rates compatible. The dosage equations obtained coefficients of determination above 94%. Finally, an empirical constant of splitting/compressive ratio of 0,16 and 0,14 for the yellow and purple soil, respectively, was found.
DOI: 10.6084/m9.figshare.14321599
title: Variables influence on splitting tensile and unconfined compressive strength of two sedimentary stabilized-cement soils

description: ABSTRACT This paper evaluates the development of splitting tensile strength (qt) and unconfined compressive strength (qu) of two soils artificially cemented over 28 days. For this, two silty soils (yellow and purple) characteristics of the Guabirotuba Formation of Curitiba/Brazil were stabilized with initial high strength cement with percentages of 3, 5, 7 and 9% in reference to the dry mass of the soils. Specimens with 50 mm diameter and 100 mm high (volume of 196,35 cm3) were molded with the different cement contents (C), different molding dry unit weights (γd), and molding moisture (ω) constant at 23% and subjected to tests of unconfined compression and splitting tensile. The ratio of voids/lime represented by the porosity/volumetric cement content ratio (η/Civ) was used to evaluate the development of qu and qt in addition to variables such as C, η and γd. The results show an increase of the mechanical resistance with the increase of the cement content and with the decrease of the voids (i.e., higher specific dry weight and lower η). A dosing equation for qu and qt of the soils studied and mixed with cement was developed using the η/Civ ratio adjusted to an exponent 0,44 to make η/Civ-qu qt variation rates compatible. The dosage equations obtained coefficients of determination above 94%. Finally, an empirical constant of splitting/compressive ratio of 0,16 and 0,14 for the yellow and purple soil, respectively, was found.
DOI: 10.6084/m9.figshare.14321601
title: Excessive coverage effect (over peening) in the blasting operation of aluminum alloy “AA 7475-T7351” with steel shot

description: ABSTRACT Aluminum and its alloys are widely used in the aeronautics industry due to its high lightness and ductility, and it can add other elements, thus changing its characteristics. Fatigue is the major cause of failure of metal materials due to the dynamic and oscillating stresses of the finished materials. The objective of this work is to evaluate the effect of Shot Peening with coverage percentages 1blasting, 3 blasting and 10 blasting in fatigue life of aluminum alloy AA 7475-T351. Shot Peening is a cold surface treatment used to increase fatigue life of the alloy by inducing residual stresses of compression on the surface of the part. In the Shot Peening process, spherical steel grids of type S230 were used, in which the specimens were subjected to 1blasting, 3 blasting and 10 blasting coverage in two stress levels (42 Ksi and 50 Ksi). The results presented in the fatigue tests and electron scanning (SEM) showed the increase in the mechanical properties of all the samples, and those exposed to 1 blasting and 3 blasting presented better results.
DOI: 10.6084/m9.figshare.14321601.v1
title: Excessive coverage effect (over peening) in the blasting operation of aluminum alloy “AA 7475-T7351” with steel shot

description: ABSTRACT Aluminum and its alloys are widely used in the aeronautics industry due to its high lightness and ductility, and it can add other elements, thus changing its characteristics. Fatigue is the major cause of failure of metal materials due to the dynamic and oscillating stresses of the finished materials. The objective of this work is to evaluate the effect of Shot Peening with coverage percentages 1blasting, 3 blasting and 10 blasting in fatigue life of aluminum alloy AA 7475-T351. Shot Peening is a cold surface treatment used to increase fatigue life of the alloy by inducing residual stresses of compression on the surface of the part. In the Shot Peening process, spherical steel grids of type S230 were used, in which the specimens were subjected to 1blasting, 3 blasting and 10 blasting coverage in two stress levels (42 Ksi and 50 Ksi). The results presented in the fatigue tests and electron scanning (SEM) showed the increase in the mechanical properties of all the samples, and those exposed to 1 blasting and 3 blasting presented better results.
DOI: 10.6084/m9.figshare.14321602
title: Influence of residual stress on the sliding wear of AISI 4340 steel

description: ABSTRACT Mechanical components and structures wear out as a result of friction between surfaces in relative motion. Residual stresses play an important role for the tribological performance of components since compressive residual stresses yield positive effects on wear resistance. However, the real effect of residual stresses on the tribological performance of surfaces is not entirely clear. The objective of this work is to evaluate the residual stress behavior during a pin-on-disk wear test of quenched and tempered AISI 4340 disk specimens against a counter-body of steel AISI E 52100. Tests were performed in shot peened and non-shot peened specimens in six steps and residual stresses were evaluated after each one by X-ray diffraction technique using sin2y method. The results shown that wear rate of the shot peened specimens was approximately fifty percent lower. Shot peening induced compressive residual stresses contributed to this effect even though they were modified during the pin-on-disk test.
DOI: 10.6084/m9.figshare.14321602.v1
title: Influence of residual stress on the sliding wear of AISI 4340 steel

description: ABSTRACT Mechanical components and structures wear out as a result of friction between surfaces in relative motion. Residual stresses play an important role for the tribological performance of components since compressive residual stresses yield positive effects on wear resistance. However, the real effect of residual stresses on the tribological performance of surfaces is not entirely clear. The objective of this work is to evaluate the residual stress behavior during a pin-on-disk wear test of quenched and tempered AISI 4340 disk specimens against a counter-body of steel AISI E 52100. Tests were performed in shot peened and non-shot peened specimens in six steps and residual stresses were evaluated after each one by X-ray diffraction technique using sin2y method. The results shown that wear rate of the shot peened specimens was approximately fifty percent lower. Shot peening induced compressive residual stresses contributed to this effect even though they were modified during the pin-on-disk test.