Article
Materials Science, Multidisciplinary
A. S. Grenadyorov, V. O. Oskirko, A. N. Zakharov, I. M. Goncharenko, V. A. Semenov, S. V. Rabotkin, A. A. Solovyev
Summary: This paper discusses the effect of hydrogen-free active screen plasma nitriding on AISI 316L austenitic stainless steel. The results show that the active screen can form hard diffusion layers at lower temperatures and improve corrosion resistance. However, with longer process time, the corrosion resistance decreases.
METALS AND MATERIALS INTERNATIONAL
(2023)
Article
Engineering, Mechanical
M. Naeem, J. C. Diaz-Guillen, Ayesha Khalid, I Guzman-Flores, R. Munoz-Arroyo, Javed Iqbal, R. R. M. Sousa
Summary: In this study, high-temperature plasma nitriding was used to improve the surface hardness and wear resistance of AISI-1045 steel. Post-oxidation treatment was applied to the nitrided samples to investigate its effect. The results showed that the nitrided sample had a white layer, while post-oxidation transformed it into hematite and magnetite phases. The hardness of the nitrided samples significantly increased, although post-oxidation caused a slight decrease. The thickness of the nitrided layer and oxide layer increased with post-oxidation treatment. The nitrided sample exhibited abrasive wear, while the post-oxidized sample showed outstanding wear resistance with an adhesive wear mechanism.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
Xiao Tao, Thomas John Collins, Qingshuo Ao, Huibin Liu, Behnam Dashtbozorg, Xiaoying Li, Hanshan Dong
Summary: In this study, Fe-24Mn-2Al-0.45C TWIP steel was investigated after active screen plasma nitriding (ASPN) treatment at temperatures ranging from 350-480 degrees C. The study revealed a selective oxidation mechanism on TWIP steel during ASPN treatment at 480 degrees C, resulting in a different hardness-depth profile compared to lower temperatures.
Article
Chemistry, Physical
Tomasz Borowski
Summary: Through nitrocarburising treatment, the corrosion resistance of AISI 316L steel was enhanced, and the nitro-carbon expanded austenite layer exhibited higher corrosion resistance compared to the nitrogen austenite layer. After the breakdown of the passive layer, there was a more significant deceleration of pitting in the nitrocarburised layer compared to the nitrogen austenite layer.
Article
Materials Science, Coatings & Films
Santiago Dominguez-Meister, Inigo Ibanez, Anastasia Dianova, Marta Brizuela, Inigo Braceras
Summary: Nitriding processes can enhance the properties of titanium surfaces, with hollow cathode assisted active screen plasma proving to be an effective and fast technique. The study investigates the impact of process parameters on the surface microstructure, finishing, and hardness of titanium. Results show that nitriding can produce titanium nitride surfaces with thicknesses exceeding those of PVD coatings, and monitoring electrical contact resistance can provide valuable information on surface status evolution.
SURFACE & COATINGS TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Shun Hamashima, Akio Nishimoto
Summary: This study investigated the effect of a Ni screen on active screen plasma nitriding (ASPN) and voltage-assisted active screen plasma nitriding (S-DCPN). The results showed that using a Ni screen increased the diffusion of nitrogen atoms and nickel atoms in the sample. ASPN-treated samples with the Ni screen had lower surface hardness and higher corrosion resistance, while S-DCPN-treated samples with the Ni screen had higher surface hardness and lower corrosion resistance.
MATERIALS TRANSACTIONS
(2022)
Article
Chemistry, Physical
Chengwei Zhang, Kai Wen, Yan Gao
Summary: The microstructure and formation mechanism of the nitrided layer on surface nanocrystalline TA17 titanium alloy were studied. The nitrided layer consisted of an outer TiN layer formed by deposition of titanium nitride particles and an inner Ti2N layer formed by nitrogen diffusion into the titanium substrate. The Ti2N layer was an Al-depleted zone, indicating its formation mode of nitrogen diffusion. The TiN layer of the shot-peened sample was mainly composed of equiaxed nanograins and a small amount of columnar grains, compared to the columnar grains in the original sample. The formation of equiaxed nanocrystalline TiN was attributed to the presence of high-energy grain boundaries on the shot-peened surface.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Yasuhiro Hoshiyama, Keisuke Chiba, Tomoki Maruoka
Summary: Spheroidal graphite cast iron after ASPN treatment shows improvements in hardness, abrasion resistance, fatigue strength, and corrosion resistance. Longer treatment time results in more significant enhancements in performance.
Article
Materials Science, Multidisciplinary
Kenzo Sumiya, Shinkichi Tokuyama, Akio Nishimoto, Junichi Fukui, Atsushi Nishiyama
Summary: Low-temperature active-screen plasma nitriding (ASPN) was successfully applied to improve the bending rigidity and corrosion resistance of a small-diameter thin pipe made of austenitic stainless steel. Increasing nitriding temperature led to thicker nitriding layer, higher surface hardness, and increased bending load. Corrosion was observed only near the tip of the nitrided samples at high nitriding temperatures during salt spray test.
Article
Materials Science, Coatings & Films
Zhen Huang, Zi-Xin Guo, Lei Liu, Yuan-Yuan Guo, Jun Chen, Ze Zhang, Jin-Long Li, Yan Li, Yan-Wen Zhou, Ying-Shuang Liang
Summary: Nitriding of AISI 316L austenitic stainless steel under various pulsed bias conditions resulted in different phase structures, thicknesses, and hardness of the nitrided layer, which in turn affected the corrosion resistance of the material.
SURFACE & COATINGS TECHNOLOGY
(2021)
Article
Metallurgy & Metallurgical Engineering
Suman Patel, B. Ganguli, S. K. Chaudhury
Summary: The study found that active screen plasma nitriding of 347H austenitic stainless steel at higher temperatures results in higher hardness and lower wear loss compared to nitriding at lower temperatures, primarily due to the formation of a higher amount of hard nitride phase(s) in the nitrogen-enriched layer.
TRANSACTIONS OF THE INDIAN INSTITUTE OF METALS
(2022)
Article
Engineering, Chemical
Yukyhiro I. Oikava, Bruna C. E. S. Kurelo, Giuseppe Pintaude, Viviane T. Mazur, Xiaoying Li, Hanshan Dong
Summary: This investigation explores the friction and wear behaviors of active-screen plasma-nitrided Inconel 718 alloy in reciprocating tests under saline solution. The results show that the presence of a nitrided layer significantly reduces wear when using a steel ball as a counterbody. However, the nitrided layer does not affect the friction or wear rate of Inconel 718 when a ceramic ball is used, and abrasive wear becomes the primary mechanism.
Article
Chemistry, Physical
Xiao Tao, Yepeng Yang, Jiahui Qi, Biao Cai, W. M. Rainforth, Xiaoying Li, Hanshan Dong
Summary: Nitrogen-expanded austenite (γN), also known as S phase, is a metastable phase that has been extensively studied on AISI 304/316 stainless steel following low temperature N diffusion treatments. Nitrogen absorption and Si segregation were observed on the surface of FeCrNiSi0.5 medium entropy alloy (MEA) after active screen plasma nitriding (ASPN) treatment. The sluggish Cr segregation in the N-modified MEA surface could be attributed to Si-induced nanoprecipitation and the high equimolar Ni/Cr content in the host matrix.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Alessandro Schiavi, Claudio Origlia, Alessandro Germak, Andrea Prato, Gianfranco Genta
Summary: This study describes the experimental method and calculation model for determining the indentation moduli, work, and creep of metallic materials using macro-scale forces at room temperature. Various measurements and analysis methods were used to accurately determine these properties, with illustrative tests conducted on metal and alloy samples. Discussions were made regarding the suitability of the proposed methods and analysis.
Article
Materials Science, Coatings & Films
R. Tima, F. Mahboubi
Summary: Plasma nitriding treatment has been found to enhance the hardness and wear resistance of electroless nickel-boron coatings, with the best results achieved at a temperature of 350 degrees Celsius. Nitrogen doping suppresses grain growth, and the precipitation of h-BN phase during treatment reduces the coefficient of friction in sliding wear tests.
SURFACE & COATINGS TECHNOLOGY
(2021)
Article
Materials Science, Ceramics
M. Rocha, Francisca P. Araujo, S. Castro-Lopes, Idglan S. de Lima, Edson Cavalcanti Silva-Filho, Josy Anteveli Osajima, Carla S. Oliveira, Bartolomeu C. Viana, Luciano C. Almeida, Y. Guerra, R. Pena-Garcia
Summary: In this study, the influence of Fe and Pr addition on the structural, optical, and antibacterial properties of spherical ZnO nanoparticles synthesized via sol gel method was investigated. The lattice constants values increased while the average crystallite size decreased with varying Pr concentration. Raman and FTIR spectroscopies confirmed the single-phase formation of ZnO and the presence of oxygen vacancies. The samples exhibited agglomerated spherical morphology and the textural properties were affected by the inclusion of Fe. The synthesized materials showed promising antimicrobial activity against Escherichia coli and Staphylococcus aureus due to nanomaterial-bacteria interactions.
CERAMICS INTERNATIONAL
(2023)
Article
Physics, Multidisciplinary
Gustavo Portela de Deus, Renan Matos Moncao, Larissa Solano de Almeida, Luciana Sgarbi Rossino, Thercio Henrique de Carvalho Costa, Maxwell Santana Liborio, Michelle Cequeira Feitor, Romulo Ribeiro Magalhaes de Sousa
Summary: This study evaluates the nitriding and deposition of niobium and vanadium films on steel substrates, and investigates their properties and characteristics.
BRAZILIAN JOURNAL OF PHYSICS
(2023)
Article
Physics, Condensed Matter
Ediones Maciel de Sousa, Antonio Bruno de Vasconcelos Leitao, Petteson Linniker Carvalho Serra, Jayane Oliveira Borges, Maria Leticia Vega, Joao Victor Barbosa Moura, Thercio Henrique de Carvalho Costa, Rubens Maribondo do Nascimento, Romulo Ribeiro Magalhaes de Sousa, Cleanio da Luz Lima
Summary: This paper investigates the growth of molybdenum trioxide thin films on AISI 316 steel using the cathodic cage plasma deposition (CCPD) technique at low temperature. The study reveals that the films deposited under 50:50 and 80:20 gases composition crystallize in the orthorhombic phase without secondary phases, with thicknesses of 5 μm and 1 μm respectively. Vickers microhardness measurements show that low temperature plasma deposition maximizes the surface hardness of AISI 316 steel with excellent adhesion and plasticity.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Geosciences, Multidisciplinary
Francisco Irineudo Bezerra, Joao Herminio da Silva, Enzo Victorino Hernandez Agressot, Paulo Tarso C. Freire, Bartolomeu Cruz Viana, Marcio Mendes
Summary: Studies have improved our understanding of preservation at the Crato fossil Lagerstatte. The high degree of preservation is a result of mineralization through diffusion of ions and bacteria envelopment, mainly pyritization. However, intense weathering can diminish or obscure morphological fidelity, and little attention has been paid to post-diagenetic processes.
GEOLOGICAL MAGAZINE
(2023)
Article
Materials Science, Multidisciplinary
Jefferson F. D. F. Araujo, Andre L. A. Reis, Elder Yokoyama, Christian D. Medina, G. Fredy G. Osorio, Cleanio Luz-Lima, Anna De Falco, Caique D. A. Lima, Joao Felipe C. Silva, Lanna I. M. Sinimbu, Frederico Gutierrez, Walmir E. Pottker, Felipe A. La Porta, Leonardo A. F. Mendoza, Tahir, Tommaso Del Rosso, Antonio C. Bruno
Summary: A magnetic microscope using Hall effect sensors was constructed in this study, which was built on a gradiometric configuration with a spatial resolution of 620 μm and a magnetic moment sensitivity of 80 nAm². It can generate magnetic fields on samples by employing a small permanent magnet, and the intensity of the applied field can be adjusted by changing the distance between the magnet and the sample. The microscope achieved a spatial field uniformity of 99.7% within a 5.0 mm radius at a distance of 500 μm from the sample surface. The automation of the microscope using the LabVIEW(R) platform makes it a versatile and affordable equipment for laboratories.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Adriano S. S. Soares, Francisca P. P. Araujo, Robson Franca, Josy A. A. Osajima, Yuset Guerra, Samuel Castro-Lopes, Edson C. C. Silva-Filho, Francisco E. E. Santos, Luciano C. C. Almeida, Bartolomeu C. C. Viana, Ramon R. Pena-Garcia
Summary: In this study, Co-doped ZnO structures were synthesized using the co-precipitation method, and the influence of pH on their structural, optical, morphological properties, and photocatalytic response towards ibuprofen was investigated. It was found that the growth of ZnO structures was affected by the pH, and the substitution of Co2+ ions in the host lattice led to an increase in lattice constants. The samples synthesized at pH = 7 exhibited spherical nanoparticles that self-assembled into hexagonal disk-like structures, while nanorods were observed for samples synthesized at pH = 10 and 13. Photoluminescence spectra analysis revealed the presence of structural defects, mainly single and doubly ionized oxygen vacancies, which, together with pH and dopant, contributed to variations in the optical band gap. Lastly, the photocatalytic response towards Ibuprofen under UV irradiation was enhanced in the presence of H2O2, suggesting improved photocatalytic properties of Co-doped ZnO under optimized conditions.
JOURNAL OF MATERIALS RESEARCH
(2023)
Article
Chemistry, Inorganic & Nuclear
Caique Diego de Abreu Lima, Roniel dos Santos Sousa, Antonio Werbeson Miranda, Joao Victor Barbosa Moura, Gardenia de Sousa Pinheiro, Bartolomeu Cruz Viana, Iara Souza Lima, Thiago Mielle Brito Ferreira Oliveira, Oswaldo Baffa, Jefferson Ferraz Damasceno Felix Araujo, Cleanio da Luz Lima
Summary: This study investigated the synthesis, characterization, and thermal stability of pure and Al ion-exchange titanate nanotubes (Na2Ti3O7 and NaxAlyTi3O7, respectively). The results revealed the obtainment of sodium titanate and aluminum titanate nanotubes with different average lengths and diameters. The presence of Al ions in the crystal lattice affected the energy exchange between the unpaired species and the lattice. The thermal stability of sodium titanate nanotubes was influenced by sodium ions, while the incorporation of Al3+ ions into the nanotube lamellae decreased the thermal stability of aluminum titanate nanotubes.
SOLID STATE SCIENCES
(2023)
Article
Metallurgy & Metallurgical Engineering
Francisco Rafael Campos de Macedo, Romulo Ribeiro Magalhaes de Sousa, Jose Wellinton Nogueira Jr, Cleanio Luz-Lima, Maxwell Santana Liborio, Anderson de Oliveira Lobo, Vladimir Jesus Trava-Airoldi, Fernanda Roberto Marciano, Michelle Cequeira Feitor, Thercio Henrique de Carvalho Costa, Rubens Maribondo do Nascimento
Summary: Plasma nitriding is widely used to improve material properties, but it often leads to nonuniformity. Cathodic cage plasma nitriding (CCPN) eliminates defects and a duplex treatment of CCPN and TiN deposition is used on SINTER30 tool steel for the first time. Vickers microhardness tests and other characterization methods show that TiN post-coating achieves higher surface hardness and all groups exhibit increased microhardness compared to untreated substrates. The prior plasma nitriding treatment enhances substrate surface hardening, and the best condition is simultaneous duplex treatment with the sample inside the titanium cage. Suitable TiN layers improve film adhesion, correlated to load-bearing capacity.
STEEL RESEARCH INTERNATIONAL
(2023)
Article
Materials Science, Ceramics
C. Alves, J. Matilla-Arias, F. Guerrero, S. Castro-Lopes, Y. Guerra, Bartolomeu C. Viana, E. Padron-Hernandez, Joao M. Soares, R. B. da Silva, Marcos G. Ghislandi, R. Pena-Garcia
Summary: In this study, the influence of La3+ cations insertion on the crystallography, morphology, and magnetic properties of Y3Fe5-xLaxO12 compound was investigated using the sol-gel method. The Rietveld refinement method was used to confirm the Fe3+ by La3+ cations replacement and quantify the structural parameters. The results showed that La3+ cations insertion significantly affected the lattice constant, crystallite size, microstrain, sites occupancy, bond angles and distances of the YIG crystal structure.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Y. Guerra, L. Leal, M. Cabrera-Baez, E. Padron-Hernandez, S. Castro-Lopes, Bartolomeu C. Viana, G. Abreu, J. Caland, P. Matos-Rodrigues, F. Santos, J. Matilla-Arias, R. Pena-Garcia
Summary: Yttrium iron garnet (YIG) has appropriate physical properties for applications in microwave, magneto-optical devices, and spintronics. This study investigated the cation's distribution, valence states, and oxygen vacancies in Y2.98Er0.02Fe5-yCryO12 compound. Transmission electron microscopy and selected area electron diffraction confirmed the coral type structures and crystalline nature of YIG. X-ray photoelectron spectroscopy was used to identify valence states and oxygen vacancies, while electron paramagnetic resonance measurements detected the magnetic contributions of Fe and Cr ions. The saturation magnetization decreased with an increase in Cr content, which was explained by a phenomenological model.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Multidisciplinary
Keyla R. B. da Silva Costa, Marcel Leiner de Sa, Francilio de Carvalho Oliveira, Dalton Dittz, Bianca Sousa Leal, Joao Marcelo de Castro e Sousa, Guilherme J. P. Abreu, Tainara G. de Oliveira, Suziete B. S. Gusmao, Anupama Ghosh, Yuset Guerra, Bartolomeu C. Viana
Summary: Sodium titanate nanotubes (NaTiNT) were synthesized and intercalated with gallium and/or cerium ions, forming a complex heterostructure. These hybrid nanomaterials showed increased cytotoxic activity in melanoma cells, indicating their potential in health applications. The ion exchange reactions preserved the original tubular structure of the nanotubes but resulted in significant changes in their surface and interlamellar environment.
JOURNAL OF NANOPARTICLE RESEARCH
(2023)
Article
Physics, Multidisciplinary
M. V. M. Filho, M. Naeem, R. M. Moncao, J. C. Diaz-Guillen, H. M. Hdz-Garcia, T. H. C. Costa, Kashif Safeen, Javed Iqbal, K. H. Khan, R. R. M. Sousa
Summary: In this study, a cathodic cage plasma deposition (CCPD) system equipped with a vanadium cathodic cage is used to deposit vanadium nitride coating on AISI-420 steel. The aim of this study is to improve the tribological and mechanical properties of the steel. The results show that the vanadium nitride coating has a polycrystalline structure and can significantly enhance the hardness and adhesion of the sample. Moreover, the coating is able to reduce the wear rate and friction coefficient, leading to improved mechanical properties of the steel.
Article
Spectroscopy
R. F. Silva, C. Luz-Lima, P. T. C. Freire, F. E. A. Melo, G. S. Pinheiro
Summary: The properties of C7H12N2O5 crystal were studied under high-temperature conditions using vibrational spectroscopy and thermal analysis techniques. The results showed that the material undergoes a reversible order-disorder phase transition at 373 K, where changes in the vibrational spectra, especially in the vibrational modes of the hydrogen bonds, were observed. The phase transition of the α-Asp-Ala crystal (around 373 K) involves changes in hydrogen bonds, possibly the rupture of at least one of them, and a change in the molecular conformation in the unit cell.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2023)
Article
Spectroscopy
A. N. C. Ferreira, W. C. Ferreira, A. V. Duarte, C. C. Santos, P. T. C. Freire, C. Luz-Lima, J. V. B. Moura
Summary: In this study, the temperature-dependent behavior of monoclinic silver dimolybdate (m-Ag2Mo2O7) microrods was investigated using in situ Raman scattering. The m-Ag2Mo2O7 microrods were synthesized by conventional hydrothermal method at 423 K for 24 h. The structural phase transition from monoclinic to triclinic structure was observed at 698 K-723 K, accompanied by the melting process at 773 K. No morphological changes were observed during the structural phase transition at 723 K, while the growth of nanowires was observed on the Ag2Mo2O7 microrods in the triclinic structure at 773 K.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2023)
