Article
Chemistry, Multidisciplinary
Tatsuhiko Aizawa, Imron Rsadi, Ersyzario Edo Yunata
Summary: This paper focuses on plasma diagnosis of a N-2-H-2 gas mixture for nitriding process optimization. It is found that hydrogen has a significant impact on plasma generation, with an optimum hydrogen content of 20%. Experimental results demonstrate that optimizing the hydrogen gas content can improve surface hardness and achieve low temperature nitriding under high nitrogen flux.
APPLIED SCIENCES-BASEL
(2022)
Article
Materials Science, Coatings & Films
T. Bergelt, P. Landgraf, T. Grund, G. Braeuer, T. Lampke
Summary: Nitriding is a common method to improve the surface properties of steels. This study aims to numerically describe a plasma-nitriding process for high-alloy tool steel and nitriding steel, and predict the resulting layer thickness and nitrogen distribution. The results show that the nitriding zone increases with temperature and time, and areas with carbides have lower layer thicknesses.
SURFACE & COATINGS TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Jiqiang Wu, Changjun Mao, Kunxia Wei, Jing Hu
Summary: By adding titanium in plasma nitriding process, a nitriding layer with enhanced properties can be obtained, including thicker ductile diffusion layer, thinner brittle compound layer, and higher surface hardness.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Materials Science, Multidisciplinary
Mariana Correa Rossi, Pedro Akira Bazaglia Kuroda, Larissa Solano de Almeida, Luciana Sgarbi Rossino, Conrado Ramos Moreira Afonso
Summary: This study aims to improve the microhardness and wear properties of as-cast titanium samples (CP-Ti, Ti-Al-4V, and TNZ-33) by creating a hard surface through plasma nitriding. The presence of nitrides was evaluated using XRD, and the microstructure and chemical composition were analyzed using electron microscopy and EDS. Plasma nitriding resulted in the formation of TiN on CP-Ti, TiN and Ti2N on Ti-6Al-4V, and TiN and ZrN on TNZ-33. The hardness of all materials significantly increased after nitriding, and the wear properties were improved.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Coatings & Films
Jiawei Yao, Fuyao Yan, Baofeng Chen, Ying Yang, Yueming Xu, Mufu Yan, Yanxiang Zhang
Summary: Simultaneous plasma nitriding and tempering on as-solutioned M50 steel achieves high surface hardness and through-hardened core, significantly increasing nitrided layer thickness and forming a high hardness layer, leading to reduced friction coefficient and improved wear resistance. The nitrided layer with gradient nano-structure was observed by TEM, explaining the observed supersaturation of nitrogen in the sub-surface layer as a result of spinodal decomposition.
SURFACE & COATINGS TECHNOLOGY
(2021)
Article
Materials Science, Coatings & Films
Jiaqin Liu, Xiaofang Wang, Yin Hu, Lizhu Luo, Chunli Jiang, Fan Liu, Wei Jin, Kangwei Zhu, Zhong Long, Kezhao Liu
Summary: Surface modification technologies have been used to improve the mechanical properties of Ti and its alloys. In this study, the influence of different H2/(N2 + H2) ratio on the microstructure of Ti specimens nitrided by cathodic cage plasma nitriding (CCPN) was investigated. It was found that the compound layer thickness and surface hardness increased with the introduction of H2, but the tensile properties were deteriorated due to the generation of titanium hydride during nitriding process.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Engineering, Manufacturing
Mahyar Afshar-Mohajer, Xingwei Yang, Rong Long, Min Zou
Summary: Micro/nano-hierarchical structures composed of nanohairs on top of micropillars were produced using high-resolution two-photon lithography additive manufacturing technique. Varying the tapering angle of the micropillar and the length of the nanohairs allowed control over the effective stiffness of the structures. In-situ monitoring of the structural deformation and frictional response revealed that changes in structure stiffness through 3D printing could affect the onset of sliding motion, friction force, and coupling between nanohair and micropillar deformation, providing new directions for friction and deformation control.
ADDITIVE MANUFACTURING
(2023)
Article
Nanoscience & Nanotechnology
Hee-Seon Kim, Min-Kyung Ji, Woo-Hyung Jang, Khurshed Alam, Hyun-Seung Kim, Hoon-Sung Cho, Hyun-Pil Lim
Summary: The mulberry surface developed through nitriding and anodic oxidation showed enhanced antibacterial activity compared to the control, while additional graphene oxide deposition improved biocompatibility and facilitated osteoblast adhesion, proliferation, and differentiation. The combination of the mulberry surface and graphene oxide deposition can potentially prevent peri-implantitis and promote osseointegration.
INTERNATIONAL JOURNAL OF NANOMEDICINE
(2021)
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
Engineering, Mechanical
Stefanie Hoja, Behrad Komeili Birjandi, Henning Hasselbruch, Jeremy Epp
Summary: This study investigated the effect of combining nitriding and induction hardening on the surface layer performance of gears, with a focus on wear resistance. The results showed that specimens subjected to nitriding-only treatment exhibited better wear resistance compared to those subjected to induction hardening after nitriding.
Article
Materials Science, Multidisciplinary
J. Valdes, J. Solis, R. Mercado, J. Oseguera, H. Carreon, C. Aguilar, A. Medina
Summary: After plasma nitriding treatment, the nitrided compound layer of AISI 4140 steel was approximately 5.0 μm thick, with significantly increased microhardness. As the treatment time increased, the abrasivity of the samples decreased due to the increase in nitrided phases and the formation of nanocrystalline size of nitrides.
Article
Metallurgy & Metallurgical Engineering
Junji Miyamoto, Kazushige Tokuno, Masahiro Hagino
Summary: Experimental results showed that sputtered Fe deposited as alpha-Fe or gamma'-Fe4N onto the sample surface during plasma nitriding. The depth of the nitrided layer remained the same under conditions where sputtering did not occur, but increased as the negative bias voltage V-Fe was increased. The presence of FexN on the sample surface, in addition to neutral species, resulted in greater depth of the nitrided layers compared to layers formed only by neutral species.
ISIJ INTERNATIONAL
(2021)
Article
Materials Science, Multidisciplinary
Ji Sun, Jie Li, J. M. Xie, Yang Yang, W. P. Wu, Xiang Zhou, S. H. Zhang, Q. M. Wang
Summary: The effects of arc discharge plasma nitriding on the structural, mechanical, tribological, and corrosion properties of AISI 420 stainless steel were investigated. It was found that nitriding at 400 degrees C resulted in the formation of an ε-Fe2-3N phase with unsatisfactory wear resistance but excellent corrosion properties. Nitriding at 460 degrees C led to the formation of an aN phase, which exhibited superior wear resistance but degraded corrosion performance. Nitriding at 420 and 440 degrees C resulted in desirable wear and corrosion performance.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Engineering, Multidisciplinary
Jeyachandran Vivek, P. Veerathevar Arul Kumar, Kuzhanthai Anton Savio Lewise, Viruthachaam Velmurugan
Summary: This study investigates the effects of treated graphite electrodes on frontal and lateral wear during electrical discharge machining of superalloys. The results show that the hardness of the graphite electrode produced by the duplex process is 54% higher than that of untreated graphite, and the frontal and lateral wear are reduced by 49% and 42% respectively using a 900 mu s pulse duration.
SADHANA-ACADEMY PROCEEDINGS IN ENGINEERING SCIENCES
(2022)
Article
Materials Science, Multidisciplinary
S. C. Bodner, M. Meindlhumer, T. Ziegelwanger, H. Winklmayr, T. Hatzenbichler, C. Schindelbacher, B. Sartory, M. Krobath, W. Ecker, N. Schell, J. Keckes
Summary: The mechanical properties of case modified steels are determined by the near-surface gradients of residual stresses, microstructures, phases, and chemical composition. High-energy synchrotron X-ray diffraction was used to characterize these gradients in different steels, revealing complex relationships between these parameters.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Chemistry, Multidisciplinary
Tatsuhiko Aizawa, Tomomi Shiratori, Yoshihiro Kira, Tadahiko Inohara
APPLIED SCIENCES-BASEL
(2020)
Article
Materials Science, Multidisciplinary
Tatsuhiko Aizawa, Tomoaki Yoshino, Tadahiko Inohara
Article
Crystallography
Tatsuhiko Aizawa, Tomoaki Yoshino, Ko-Ichi Ito, Tatsuya Fukuda
Article
Chemistry, Physical
Tatsuhiko Aizawa, Tomoaki Yoshino, Tatsuya Fukuda, Tomomi Shiratori
Article
Chemistry, Multidisciplinary
Tatsuhiko Aizawa, Tomoaki Yoshino, Yohei Suzuki, Tomomi Shiratori
Summary: The study investigates the effectiveness of using plasma-carburized punch in cold forging of biomedical titanium alloys, which can significantly reduce adhesion of metallic titanium and titanium oxide debris, resulting in a harder surface with carbon supersaturation. This process enhances thinning efficiency during cold forging of biomedical titanium alloys.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Physical
Tatsuhiko Aizawa, Tomoaki Yoshino, Yohei Suzuki, Tomomi Shiratori
Summary: The plasma-carburized tool steel punch effectively reduced galling and residual strains in forging pure titanium wire, resulting in a titanium ribbon with micro-pillared microtexture.
Article
Chemistry, Analytical
Tatsuhiko Aizawa, Tomomi Shiratori, Yoshihiro Kira, Tomoaki Yoshino, Yohei Suzuki
Summary: The CVD diamond coated WC and Co sintered alloy punch was trimmed using femtosecond laser machining to sharpen its edge and simultaneously nanostructure its side surface. The sharpened edge and homogeneous edge profile significantly reduced the affected layer width when piercing electrical amorphous steel sheet stack, preventing various types of damage and improving the performance of the tool.
Article
Chemistry, Analytical
Tatsuhiko Aizawa, Tomoaki Yoshino, Yohei Suzuki, Tadahiko Inohara
Summary: A new data transformation method for micro-manufacturing using a topological model for a micro-/nano-texture is proposed in this study. The method utilizes femtosecond laser printing and plasma nitriding to create customized textures on metallic products.
Article
Chemistry, Physical
Yukiya Komori, Yohei Suzuki, Kohta Abe, Tatsuhiko Aizawa, Tomomi Shiratori
Summary: The study investigated the impact zone near the punched hole and the surface of the punch by adding nanotextures to the punch and punching electrical steel sheets. The dimensional change in each layer of the stack before and after perforation was measured for comparison with the punch diameter.
Article
Chemistry, Multidisciplinary
Tatsuhiko Aizawa, Imron Rsadi, Ersyzario Edo Yunata
Summary: This paper focuses on plasma diagnosis of a N-2-H-2 gas mixture for nitriding process optimization. It is found that hydrogen has a significant impact on plasma generation, with an optimum hydrogen content of 20%. Experimental results demonstrate that optimizing the hydrogen gas content can improve surface hardness and achieve low temperature nitriding under high nitrogen flux.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Analytical
Tatsuhiko Aizawa, Hiroki Nakata, Takeshi Nasu
Summary: An acicular microtextured sheet was developed to transfer heat radiation from a high-temperature source to a cooling medium in the infrared spectrum. By modifying the copper surface with acicular micro-texturing, a semi-regular micro-/nano-cone structure was created. The sheet emitted electromagnetic waves in the far-IR wavelength and demonstrated efficient heat radiation.
Article
Materials Science, Multidisciplinary
Tatsuhiko Aizawa, Kenji Fuchiwaki
Summary: A carbon-supersaturated high-speed steel punch was used for the fine blanking of pure titanium plates, which showed no severe chemical galling even after repeated operations. The formation of agglomerated free-carbon film due to the carbon-supersaturated punch led to the slight deposition of titanium debris fragments at the punch edges. The in situ lubrication by the free carbon tribofilms resulted in completely burnished surfaces of pure titanium blanks.
C-JOURNAL OF CARBON RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Tatsuhiko Aizawa, Hiroki Naka, Takeshi Nasu, Yoshiro Nogami
Summary: Vertically aligned graphite substrate (VGS)-copper packaging with micro-texturing is effective in improving robustness against thermal gradient loading. By forming micro-groove arrays using fast-rate oxygen plasma etching, filling them with copper deposits and covering the VGS surfaces, and subjecting the specimens to thermal transient loading tests, the high rib height copper rib-structured VGS-Cu package demonstrated no delamination and sufficient robustness.
C-JOURNAL OF CARBON RESEARCH
(2022)
Article
Engineering, Mechanical
Tatsuhiko Aizawa, Tatsuya Funazuka, Tomomi Shiratori
Summary: A new near-net forging process for titanium and titanium alloys was proposed using a carbon-supersaturated punch and die. By forming carbon-based tribofilm on the contact interface between the dies and work materials, a low frictional state was maintained during the forging process, even with high thickness reduction. Work hardening was suppressed, eliminating the need for additional annealing. The galling-free forging behavior of pure titanium and beta-phase titanium alloy wires was demonstrated with reduction in thickness reaching 58% and 45% respectively.
Article
Engineering, Manufacturing
Tatsuhiko Aizawa, Yohei Suzuki, Tomoaki Yoshino, Tomomi Shiratori
Summary: This study explored the possibility of using additive manufacturing, specifically plasma-assisted 3D printing, to fabricate a pair of T-shaped punch and die. The results showed that the fabricated punch and die exhibited highly accurate piercing behavior.
JOURNAL OF MANUFACTURING AND MATERIALS PROCESSING
(2022)
