Article
Chemistry, Analytical
Guijie Wang, Hongbin Xia, Weimin Huang, Junru Yang, Bing Liu, Liang Yuan
Summary: This paper investigates the corrosion resistance of NiTi shape memory alloy and analyzes its impedance spectrum, potentiodynamic polarization, and corrosion morphology using multiple analysis methods. The experimental results show that the corrosion resistance of the alloy improves after electrochemical polishing, and different corrosion morphologies are observed.
Article
Materials Science, Multidisciplinary
Ali Rasouli, Homam Naffakh-Moosavy
Summary: NiTi shape memory alloy (SMA) offers various industrial applications, but the formation of intermetallic compounds in the joint with Ni20Cr alloy leads to reduced mechanical properties and increased hardness. Post-weld heat treatment can alter the microstructure and mechanical properties of the welded joint and produce NiTi intermetallic phase.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Engineering, Mechanical
Chao Yu, Han M. Jiang, Di Song, Yilin Zhu, Guozheng Kang
Summary: This article introduces the functional devices made of NiTi shape memory alloys (SMAs) and serviced in a hydrogen-rich environment. Experimental results show that the martensite transformation (MT) of NiTi SMA changes significantly after charging H, due to hydrogen diffusion in the material and an additional transformation resistance caused by absorbed hydrogen atoms. In order to describe the super-elastic deformation of NiTi SMA wires in a hydrogen-rich environment, a multi-scale diffusional-mechanically coupled constitutive model is constructed.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Engineering, Mechanical
Yanqiu Zhang, Shuyong Jiang, Guilong Zhao, Kairui Guo
Summary: The mechanical behavior and phase transformation of nanocrystalline NiTi shape memory alloy under complex stress states were investigated using molecular dynamics (MD) simulation. Tension-compression asymmetry was observed in terms of transformation strain, critical transformation stress, dissipation energy density, martensite variant, and martensite domain. A new transformation yield criterion based on the Bouvet and Patoor criteria was proposed to accurately describe the transformation stress anisotropy in complex stress states.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Mechanics
Qianhua Kan, Yong Zhang, Yangguang Xu, Guozheng Kang, Chao Yu
Summary: The functional degeneration of super-elastic NiTi shape memory alloy (SMA) rods was investigated under cyclic tension-unloading and compression-unloading experiments. The results showed that the functional degeneration exhibited a strong tension-compression asymmetry, which was caused by the initial mixed textures, polarity of martensite transformation, and the interaction between martensite transformation and dislocation slipping. Furthermore, the dependence of functional degeneration on the applied stress level was discussed.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2023)
Review
Materials Science, Multidisciplinary
Woo-Chul Kim, Ka-Ram Lim, Won-Tae Kim, Eun-Soo Park, Do-Hyang Kim
Summary: This paper introduces a new alloy concept based on NiTi alloys, with both glass forming ability and shape memory characteristics. By suppressing the formation of brittle intermetallic compounds, the physical properties of shape memory alloys fabricated using glass precursor can be maximized. The structure and properties of multicomponent SMA systems are also discussed.
PROGRESS IN MATERIALS SCIENCE
(2022)
Review
Materials Science, Multidisciplinary
Woo-Chul Kim, Ka-Ram Lim, Won-Tae Kim, Eun-Soo Park, Do-Hyang Kim
Summary: A new concept has been introduced for an alloy with both glass forming ability and shape memory characteristics, which can enhance the physical properties of shape memory alloys by suppressing the formation of brittle intermetallic compounds and enabling the formation of nanocrystalline structure. The glass precursor is not only suitable for small-sized devices but also allows for production of intricate geometry through thermoplastic forming, with shape memory effect or superelasticity manifested after crystallization. The study reviews typical NiTi-based SMAs and multicomponent SMAs fabricated using glass precursor, discussing the effects of quaternary doping and the properties of multicomponent SMA systems.
PROGRESS IN MATERIALS SCIENCE
(2021)
Article
Engineering, Industrial
H. Z. Lu, H. W. Ma, W. S. Cai, X. Luo, S. G. Qu, J. Wang, R. Lupoi, S. Yin, C. Yang
Summary: This study systematically investigated the density, surface roughness, and properties of selective laser melted NiTi shape memory alloys (SMAs). The findings revealed that increasing laser energy density did not guarantee dense SMAs, and the phase composition and transformation temperatures varied with slight changes in laser power and scanning speed. Mechanical tests showed that the SLM NiTi alloys made under the optimal process parameters exhibited high tensile strength and elongation. Shape memory tests demonstrated excellent recovery rates and deformation recovery of the alloys due to the presence of high-density dislocations and Ti2Ni nanoprecipitates. These findings suggest that SLM NiTi parts have promising shape memory properties for industrial applications.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
K. N. Chaithanya Kumar, Atharva Pagare, H-G Brokmeier, M. Sankar, Nobert Schell, K. S. Suresh
Summary: The in-situ deformation of Ni rich NiTi shape memory alloy was characterized using synchrotron diffraction. The study found that applied stress affects the texture of material and restricts the stress induced martensitic transformation. A strong lattice correspondence between the austenite and martensite phases along with a strong variant selection was observed.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Polymer Science
Sneha Samal, Olga Kosjakova, David Vokoun, Ivo Stachiv
Summary: Both PMMA and NiTi possess shape memory and biocompatibility behavior. The study focuses on the preparation of PMMA-NiTi composites and the investigation of their properties. The experimental results agree well with the model, and the change in shape is attributed to the difference in coefficients of thermal expansion between PMMA and NiTi. The composite has potential applications as actuators and sensor elements.
Article
Materials Science, Multidisciplinary
Hiroyuki Kato
Summary: The study found that nickel titanium shape memory alloy has a large amount of latent heat during the martensitic transformation, making it a potential candidate for heat storage material.
JOURNAL OF MATERIALS SCIENCE
(2021)
Article
Engineering, Mechanical
Zhihao Zhao, Dongjie Jiang, Yao Xiao, Jianping Lin, Junying Min
Summary: The superelasticity of nanocrystalline NiTi alloys originates from stress-induced martensitic transformation, which may exhibit strain localization. Measuring the intrinsic response during the reverse transformation is difficult, hindering analysis of localized phase transformation phenomena. This study proposes a novel experimental methodology to extract the complete intrinsic response of SMAs and applies it to nanocrystalline superelastic NiTi, providing insights into the deformation mechanisms and paving the way for accurate analysis and design of relevant structures.
EXTREME MECHANICS LETTERS
(2023)
Article
Materials Science, Ceramics
Alberto Z. Fatichi, Mariana G. de Mello, Karina D. Pereira, Luisa G. M. Antonio, Augusto D. Luchessi, Rubens Caram, Alessandra Cremasco
Summary: The electrochemical, structural, and biological properties of self-organized amorphous and anatase/rutile titanium dioxide (TiO2) nanotubes deposited on Ti-35Nb-4Zr alloy through anodization-induced surface modification were investigated. The study found that anatase TiO2 exhibited higher surface corrosion resistance and cell viability compared to amorphous TiO2, indicating the importance of TiO2 nanotube crystallization in the material's electrochemical behavior and biocompatibility.
CERAMICS INTERNATIONAL
(2022)
Article
Nanoscience & Nanotechnology
Peng Chen, Yunfan Liu, Na Min, Meimei Wang, Xiaorong Cai, Mingjiang Jin, Xuejun Jin
Summary: In this study, an excellent two-way shape memory effect (TWSME) with large magnitude and small cyclic degradation of NiTi wires is achieved by combining martensite deformation and nanocrystallization. The wires exhibit a maximum TWSME strain of 7.37% after being pre-deformed to 11% and maintain a stable strain of 6.88% after 20 cycles. The excellent TWSME is attributed to the dislocation structures induced by martensite deformation and the nanocrystalline strengthened matrix.
SCRIPTA MATERIALIA
(2023)
Article
Engineering, Mechanical
Bo Xu, Chong Wang, Qingyuan Wang, Chao Yu, Qianhua Kan, Guozheng Kang
Summary: A new Ni-concentration dependent phase field model is proposed to investigate the elastocaloric effects (eCEs) of NiTi shape memory alloys (SMAs) with different Ni-concentration gradients and various aspect ratios. The results show that the martensite transformation start stress of NiTi SMAs increases progressively during tensile loading, leading to a small stress-strain hysteresis loop and improvement in the coefficient of performance of material (COPmat). The optimal eCE is achieved when the sample has both a small Ni-concentration gradient and a small aspect ratio, or a large Ni-concentration gradient and a large aspect ratio.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Materials Science, Ceramics
Alireza Mehrvarz, Yashar Ghazanfar-Ahari, Jafar Khalil-Allafi, Soheil Mahdavi, Mohamadreza Etminanfar
Summary: In this study, hydroxyapatite/ZnO nanocomposite coatings were developed on NiTi superelastic alloy using pulse electrodeposition technique at different current densities. Coatings formed at 6 mA/cm2 exhibited compact and uniform composite layers, with improved corrosion resistance and bioactivity.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
Hossein Maleki-Ghaleh, M. Hossein Siadati, Yadollah Omidi, Majid Kavanlouei, Jaleh Barar, Ali Akbari-Fakhrabadi, Khosro Adibkia, Younes Beygi-Khosrowshahi
Summary: Hydroxyapatite (HA) nanoparticles were prepared from natural bone and doped with zinc (Zn-HA) using solid state reaction method. The Zn-HA nanoparticles significantly improved stem cell osteogenic differentiation, making them a promising option for bone tissue engineering.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Electrochemistry
S. Ahmadiyan, J. Khalil-Allafi, M. R. Etminanfar, M. S. Safavi, M. Hosseini
Summary: The surface modification of titanium implants is crucial for both antibacterial properties and biocompatibility. The study demonstrated the importance of surface modification parameters in achieving favorable antibacterial performance and biocompatibility. The optimal approach was found to be using ethanol solvent for 2 hours etching followed by 2 hours silanisation.
TRANSACTIONS OF THE INSTITUTE OF METAL FINISHING
(2022)
Review
Chemistry, Multidisciplinary
Mir Saman Safavi, F. C. Walsh, Livia Visai, Jafar Khalil-Allafi
Summary: This article introduces the deposition techniques and biomedical applications of pure niobium oxide coatings on metallic substrates. It illustrates the properties of these coatings, including corrosion resistance, tribological characteristics and cell viability/proliferation. The critical R&D needs for improving niobium oxide coatings in the future are highlighted.
Article
Chemistry, Physical
Nazila Horandghadim, Yashar Ghazanfar-Ahari, Jafar Khalil-Allafi
Summary: In this study, antibacterial implants were developed by incorporating different amounts of multi-walled carbon nanotubes (MWCNTs) with hydroxyapatite-tantalum pentoxide (HA-Ta2O5) and applying them onto NiTi using electrophoretic deposition (EPD) method. The addition of MWCNTs increased the density of the HA-Ta2O5 coating and improved its adhesion strength to NiTi. Furthermore, the MWCNTs enhanced the antibacterial property and electrochemical behavior of the coating.
SURFACES AND INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
H. Maleki-Ghaleh, M. S. Shakeri, Z. Dargahi, M. Kavanlouei, H. Kaveh Garabagh, E. Moradpur-Tari, A. Yourdkhani, A. Fallah, A. Zarrabi, B. Koc, M. H. Siadati
Summary: The optical and electronic properties of molybdenum-doped rutile TiO2 prepared by the mechanochemical method were studied experimentally and using density functional theory (DFT). The results showed the successful incorporation of molybdenum in the crystal lattice and a reduction in the bandgap energy of rutile.
MATERIALS TODAY CHEMISTRY
(2022)
Article
Materials Science, Multidisciplinary
Hao Yu, Mohammad Sadegh Shakeri, Abbas Sabahi Namini, Seyed Ali Delbari, Quyet Van Le, Jiyoung Lee, Soo Young Kim, Sea-Hoon Lee, Ho Won Jang, Zaneta Swiatkowska-Warkocka, Mohammadreza Shokouhimehr
Summary: The microstructural characterization of TiB2-20SiC-5Si(3)N(4) composite prepared by spark plasma sintering (SPS) was investigated using HRTEM and XPS. In-situ TiN phase, TiBxNy solid solution, and h-BN phase were formed during the SPS process. Strong interfaces between TiB2, SiC, and BN phases were observed, while weak interfaces were generated due to the formation of amorphous phases. Structural defects and distortions in TiB2 and h-BN were identified as the main channels for the diffusion and transportation of boron atoms into the Si3N4 matrix for the formation of in-situ h-BN phase.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Ali Nadernezhad, Juergen Groll
Summary: A machine learning approach is used to explain the process of rendering hydrogel ink formulations printable. Thirteen critical rheological measures are identified to describe the printability, providing a qualitative and physically interpretable guideline for designing new printable materials.
Article
Materials Science, Multidisciplinary
Milad Hosseini, Jafar Khalil-Allafi, Mohamadreza Etminanfar, Mir Saman Safavi, Nora Bloise, Arash Ghalandarzadeh
Summary: This study aimed to enhance the performance of hydroxyapatite-Yttria-stabilized ZrO2 (HAp-YSZ) composite coating on Ti6Al4V implants using plasma electrolyte oxidation (PEO) technique. The concentration of YSZ nanoparticles in the electrolyte was found to influence the final characteristics of the coating. The addition of YSZ nanoparticles resulted in increased microhardness, bonding strength, and corrosion resistance of the composite coating. In vitro tests showed that the coated implants promoted apatite growth, improved cell viability and proliferation, and exhibited antibacterial activity against Escherichia coli.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
M. Abdollahi Khabisi, H. Khorsand, E. Ganjeh, M. Tahmasebi, M. H. Siadati
Summary: A Ti/Zr based solid solution with a composition of 37.5Ti-37.5Zr-15Cu-10Ni (eutectic) was successfully synthesized by mechanical alloying. The powder experienced severe deformation during the milling process, but the infrared heat treatment ensured the preservation of the nanocrystalline size. The optimal milling period was determined to be 10 hours, resulting in a crystal size of 13 nm, lattice parameter of 2.7 angstrom, and lattice strain of 0.4%.
Article
Materials Science, Multidisciplinary
Nesa Abdian, Mohamadreza Etminanfar, Seyed Omid Reza Sheykholeslami, Hamed Hamishehkar, Jafar Khalil-Allafi
Summary: Chitosan/hydroxyapatite/mesoporous SiO2-HA scaffolds were prepared and studied for drug delivery applications. The addition of mesoporous SiO2-HA particles improved the porous nature of the scaffolds. XRD results confirmed a strong interaction between chitosan and hydroxyapatite in the scaffolds. The introduction of mesoporous SiO2-HA boosted the mechanical and biological performances of the scaffolds.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Materials Science, Ceramics
Seyed Omid Reza Sheykholeslami, Jafar Khalil-Allafi, Mohamadreza Etminanfar
Summary: In this article, mesoporous SiO2/hydroxyapatite (HA) composite particles were produced and co-electrodeposited on Nitinol biomedical alloy. The characterization results showed that the composite coatings exhibited a compact morphology and hydrophobic properties, which significantly improved the corrosion resistance. Furthermore, the composite coatings provided a convenient environment for the growth and proliferation of MG-63 osteoblasts.
CERAMICS INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
F. Marashi-Najafi, J. Khalil-Allafi, S. Mahdavi
Summary: The use of functionalized nanoparticles in polymer coatings has shown promising potential for enhancing corrosion protection in biomedical applications. By characterizing the morphology, structure, and properties of various coatings, researchers have demonstrated that the inclusion of functionalized nanoparticles can significantly improve the hardness and elastic modulus of the coatings, resulting in excellent corrosion resistance.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Mir Saman Safavi, Jafar Khalil-Allafi, Amir Motallebzadeh, Cristina Volpini, Vida Khalili, Livia Visai
Summary: This study focuses on the development of surface technologies to improve the tribomechanical and biological characteristics of synthetic NiTi implants. The results show that incorporating Nb2O5 particles can lead to a more compact and hydrophilic surface. The composite coatings exhibit higher hardness and elastic modulus, as well as stronger bonding to the underlying material. The Nb2O5-reinforced HAp films have an elastic modulus close to that of cortical bone, reducing the risk of stress-shielding. Additionally, the inclusion of Nb2O5 particles also improves cell functions.
MATERIALS ADVANCES
(2023)
Review
Engineering, Manufacturing
Mir Saman Safavi, Aydin Bordbar-Khiabani, Jafar Khalil-Allafi, Masoud Mozafari, Livia Visai
Summary: Nickel-titanium (NiTi) is a shape-memory alloy with various advantages, but it faces challenges in processing and machinability. Additive manufacturing is a promising method for fabricating near-net-shape NiTi biomaterials with controlled porosity. The influence of operating parameters on mechanical properties and surface modification techniques for minimizing ion leaching are discussed.
JOURNAL OF MANUFACTURING AND MATERIALS PROCESSING
(2022)
