Gilmar Batalha - Academia.edu (original) (raw)
Papers by Gilmar Batalha
Materiali in Tehnologije, Oct 2, 2023
The production of carbide parts (cermet) by additive manufacturing, such as laser powder bed fusi... more The production of carbide parts (cermet) by additive manufacturing, such as laser powder bed fusion (L-PBF), has been a great challenge due to the complex optimization of process parameters to improve density, porosity, microcracks or abnormal growth of grains and obtain a microstructure as homogeneous as possible. This work aims to compare the evolution of the microstructure when using the conventional route of powder metallurgy, i.e., liquid phase sintering (LPS) with the L-PBF direct additive manufacturing process, considering the NbC-based carbide material. Sample compositions were prepared in w/%, samples were compacted under 50-125 MPa, without polymeric binders, and they were sintered under a vacuum at temperatures of 1330°C and 1370°C. For the L-PBF process, a vibrating device made it possible to improve the fluidity of the mixtures of three alloys, NbC-30Co, NbC-30Ni and NbC-30(Co, Ni). The mixtures exhibited low sphericity, low fluidity and compressibility, which were improved with a roller compactor. Thin powder mixture deposition layers were evenly applied and well distributed across the powder bed to avoid defects and cracks during sintering. The L-PBF process parameters varied including a power of 50-125 W and a laser scanning speed of 25-125 mm•s-1. Different microstructures, identified with a light microscope (LM) and a scanning electron microscope (SEM), and properties obtained with the two processes, direct (L-PBF) and indirect sintering (LPS), were compared.
The International Journal of Advanced Manufacturing Technology, Sep 27, 2023
Anais do Congresso Internacional de Engenharia Mecânica e Industrial
Densification and mechanical characteristics or WC-Co ! Cemented Carbides, were investigated by d... more Densification and mechanical characteristics or WC-Co ! Cemented Carbides, were investigated by dilatomerry, Hardness and bending tests, as a function o£ the two principal micro-structural parameters: the cobalt content and the particle size of carbide crystals. Vickers hardness of the studied compositions showed a linear variation with the increase of the cobalt content. By three point bending, the transverse rupture strenght increases with the cobalt conte however, for larger grain size reaches a maximum, eventually redüced by brittle phases and incomplete dispersion.. The results of brittle fracture tests were statiscally analised and fitted better to the "Weakest Link Model" (Weibull distribution) than the "Chain Model" (Gaussicin dis t ribution) .
HAL (Le Centre pour la Communication Scientifique Directe), May 1, 2021
Stacks materials are frequently applied in aeronautical industries due to its great combination p... more Stacks materials are frequently applied in aeronautical industries due to its great combination properties. Although, as per different machinabilities, choosing the cutting parameters for drilling stacks is far from simple. Usually, in industries, the machining parameters are set to suit the most hard to machine material in a stack, which increases the cutting time and productivity. Smart machining techniques contribute to the development of drilling stacks materials by adapting the parameters to the identified material. The goal in the present work is to create a map for identification based on the specific force analysis using two metallic materials: aluminum and titanium alloys, often found in aeronautic stacks. The resultant map shows distinct regions for these materials proving it could be applied to use on smart drilling techniques.
Sensors, Feb 10, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Eng, Nov 17, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Elsevier eBooks, 2014
"Comprehensive Materials Processing "provides students and professionals with a one-sto... more "Comprehensive Materials Processing "provides students and professionals with a one-stop resource consolidating and enhancing the literature of the materials processing and manufacturing universe. It provides authoritative analysis of all processes, technologies, and techniques for converting industrial materials from a raw state into finished parts or products. Assisting scientists and engineers in the selection, design, and use of materials, whether in the lab or in industry, it matches the adaptive complexity of emergent materials and processing technologies. Extensive traditional article-level academic discussion of core theories and applications is supplemented by applied case studies and advanced multimedia features. Coverage encompasses the general categories of solidification, powder, deposition, and deformation processing, and includes discussion on plant and tool design, analysis and characterization of processing techniques, high-temperatures studies, and the influence of process scale on component characteristics and behavior. Authored and reviewed by world-class academic and industrial specialists in each subject fieldPractical tools such as integrated case studies, user-defined process schemata, and multimedia modeling and functionalityMaximizes research efficiency by collating the most important and established information in one place with integrated applets linking to relevant outside sources
Materiali in Tehnologije, Oct 2, 2023
The production of carbide parts (cermet) by additive manufacturing, such as laser powder bed fusi... more The production of carbide parts (cermet) by additive manufacturing, such as laser powder bed fusion (L-PBF), has been a great challenge due to the complex optimization of process parameters to improve density, porosity, microcracks or abnormal growth of grains and obtain a microstructure as homogeneous as possible. This work aims to compare the evolution of the microstructure when using the conventional route of powder metallurgy, i.e., liquid phase sintering (LPS) with the L-PBF direct additive manufacturing process, considering the NbC-based carbide material. Sample compositions were prepared in w/%, samples were compacted under 50-125 MPa, without polymeric binders, and they were sintered under a vacuum at temperatures of 1330°C and 1370°C. For the L-PBF process, a vibrating device made it possible to improve the fluidity of the mixtures of three alloys, NbC-30Co, NbC-30Ni and NbC-30(Co, Ni). The mixtures exhibited low sphericity, low fluidity and compressibility, which were improved with a roller compactor. Thin powder mixture deposition layers were evenly applied and well distributed across the powder bed to avoid defects and cracks during sintering. The L-PBF process parameters varied including a power of 50-125 W and a laser scanning speed of 25-125 mm•s-1. Different microstructures, identified with a light microscope (LM) and a scanning electron microscope (SEM), and properties obtained with the two processes, direct (L-PBF) and indirect sintering (LPS), were compared.
The International Journal of Advanced Manufacturing Technology, Sep 27, 2023
Anais do Congresso Internacional de Engenharia Mecânica e Industrial
Densification and mechanical characteristics or WC-Co ! Cemented Carbides, were investigated by d... more Densification and mechanical characteristics or WC-Co ! Cemented Carbides, were investigated by dilatomerry, Hardness and bending tests, as a function o£ the two principal micro-structural parameters: the cobalt content and the particle size of carbide crystals. Vickers hardness of the studied compositions showed a linear variation with the increase of the cobalt content. By three point bending, the transverse rupture strenght increases with the cobalt conte however, for larger grain size reaches a maximum, eventually redüced by brittle phases and incomplete dispersion.. The results of brittle fracture tests were statiscally analised and fitted better to the "Weakest Link Model" (Weibull distribution) than the "Chain Model" (Gaussicin dis t ribution) .
HAL (Le Centre pour la Communication Scientifique Directe), May 1, 2021
Stacks materials are frequently applied in aeronautical industries due to its great combination p... more Stacks materials are frequently applied in aeronautical industries due to its great combination properties. Although, as per different machinabilities, choosing the cutting parameters for drilling stacks is far from simple. Usually, in industries, the machining parameters are set to suit the most hard to machine material in a stack, which increases the cutting time and productivity. Smart machining techniques contribute to the development of drilling stacks materials by adapting the parameters to the identified material. The goal in the present work is to create a map for identification based on the specific force analysis using two metallic materials: aluminum and titanium alloys, often found in aeronautic stacks. The resultant map shows distinct regions for these materials proving it could be applied to use on smart drilling techniques.
Sensors, Feb 10, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Eng, Nov 17, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Elsevier eBooks, 2014
"Comprehensive Materials Processing "provides students and professionals with a one-sto... more "Comprehensive Materials Processing "provides students and professionals with a one-stop resource consolidating and enhancing the literature of the materials processing and manufacturing universe. It provides authoritative analysis of all processes, technologies, and techniques for converting industrial materials from a raw state into finished parts or products. Assisting scientists and engineers in the selection, design, and use of materials, whether in the lab or in industry, it matches the adaptive complexity of emergent materials and processing technologies. Extensive traditional article-level academic discussion of core theories and applications is supplemented by applied case studies and advanced multimedia features. Coverage encompasses the general categories of solidification, powder, deposition, and deformation processing, and includes discussion on plant and tool design, analysis and characterization of processing techniques, high-temperatures studies, and the influence of process scale on component characteristics and behavior. Authored and reviewed by world-class academic and industrial specialists in each subject fieldPractical tools such as integrated case studies, user-defined process schemata, and multimedia modeling and functionalityMaximizes research efficiency by collating the most important and established information in one place with integrated applets linking to relevant outside sources