Irina Hussainova

Tallinn University of Technology | TTU · Department of Materials Engineering

The use of electronic devices that incorporate multilayer ceramic capacitors (MLCCs) is on the rise, requiring materials with good electrical properties and a narrow band gap. This study synthesized yttrium-substituted barium titanate (Ba1–xYxTiO3, BYT) using a sol–gel process at 950 °C with varying concentrations of yttrium (0 ≤ x ≤ 0.3). X-ray di...

Self-lubricating coatings extend the efficient dry-operational life of cutting and forming tools. In the current work, millimeter-thick NiCrBSi coatings with 10 wt% metal sulfide i.e. Ni3S2, CuS, or Bi2S3 were fabricated on a stainless steel substrate by laser cladding (in-situ alloying). Thermodynamic modelling utilizing the calculation of phase d...

The BTO, BFTC, and BCTF compounds were synthesized by the sol–gel method. The XRD study revealed the formation of single-phase tetragonal perovskite structures with the space group (P4mm). The crystalline parameters were studied as a function of Fe and Co contents and occupation of Ba and/or Ti sites by Fe and Co in the BTO lattice. It was found th...

In this study, we prepared a homogeneous fine powder of barium titanate (BaTiO 3 , BT) doped with different concentrations of strontium (x = 0, 0.05, 0.125, 0.15, 0.20, and 0.3) and having the composition Ba 1-x Sr x TiO 3 (barium strontium titanate, BSr x T). XRD patterns and Rietveld refinement revealed the existence of a single tetragonal phase...

3D printing technologies have expanded the possibilities of fabricating new composite materials with tailored properties, which depend on both the materials selected and the structural design at multiple length scales. Here, a catalyst-free CVD method has been used to produce hybrid materials representing 3D printed cellular α-Al2O3 substrates deco...

Strontium and Yttrium-doped and co-doped BaTiO3 (BT) ceramics with the stoichiometric formulas BaTiO3, B1-xSrxTiO3, Ba1-xYxTiO3, BaTi1-xYxO3, Ba1-xYxTi1-xYxO3, and Ba1-xSrxTi1-xYxO3 (x=0.075) noted as BT, BSrT, BYT, BTY, BYTY, and BSrTY have been synthesized through sol-gel method. X-ray diffraction (XRD) patterns of the prepared ceramics, calcined...

The scaffolds, which morphologically and physiologically mimic natural features of the bone, are of a high demand for regenerative medicine. To address this challenge, bioactive porous silicon/wollastonite (SC) scaffold has been developed for potential bone tissue engineering applications. Additive manufacturing through the selective laser melting...

It is a well-established fact, that the tribological performance of titanium and its alloys at high temperatures is poor, especially for self-mated titanium‑titanium pairs. Previous work has shown a significant improvement in mechanical and high temperature tribological behaviour (700–900 °C) for pure Ti sintered with TiB2 ceramic, occasioned by th...

Deep-UV (180-280 nm) phosphors have attracted tremendous interest in tri-band-based white light-emitting diode (LED) technology, bio- and photochemistry, as well as various medical fields. However, the application of many UV-emitting materials has been hindered due to their poor thermal or chemical stability, complex synthesis, and environmental ha...

This computational study addresses new biomimetic load-bearing implants designed to treat long bone critical-sized defects in a proximal diaphysis region. The design encompasses two strategies: a Haversian bone-mimicking approach for cortical bone and lattices based on triply periodic minimal surfaces (TPMS) for trabecular bone. Compression tests a...

In this work, hexagonal boron nitride powder was used for the lubrication of an interface of TiB2/Ti composite protected by an AlCrN coating and a ceramic Si3N4 ball. The wear behaviour of this tribo-pair in an oscillating motion was studied with an SRV tribotester at the temperature range from room temperature to 900 °C. The action of hexagonal bo...

Increasing attention is focused on developing biomaterials as temporary scaffolds that provide a specific environment and microstructure for bone tissue regeneration. The aim of the present work was to synthesize silicon-doped biomimetic multi-phase composite scaffolds based on bioactive inorganic phases and biocompatible polymers (poly(ε-caprolact...

Additive manufacturing is a rapid prototyping technology to produce complex three-dimensional scaffolds suitable for personalized medicine. In the present study, the laser powder bed fusion through a selective laser melting (SLM) approach has been applied to optimized fabrication of bio-mimicking scaffolds by using hydroxyapatite (HAp, 50 and 70 wt...

This article presents novel graphene‐based absorber materials which can be directly integrated in terahertz waveguide systems. A simple, low‐cost integration method is developed, allowing graphene augmented inorganic nanofibers to be embedded inside a metallic waveguide. In contrast to existing absorbers, the ability to embed such materials in a me...

Aluminum (Al) and its alloys are the second most used materials spanning industrial applications in automotive, aircraft and aerospace industries. To comply with the industrial demand for high-performance aluminum alloys with superb mechanical properties, one promising approach is reinforcement with ceramic particulates. Laser powder-bed fusion (LP...

The bioactive properties of hydroxyapatite (HAp) facilitate bone regeneration, however, its physico-chemical and bioactive properties can be further enhanced by ionic substitutions within the crystalline lattice. In this work, substitution with Sr²⁺ and Ag ⁺ ions was investigated for the improvement of osseointegration and antibacterial activity in...

Understanding the complex nature of wear behavior of materials at high-temperature is of fundamental importance for several engineering applications, including metal processing (cutting, forming, forging), internal combustion engines, etc. At high temperatures (up to 1000 °C), the material removal is majorly governed by the changes in surface react...

This work reports on the spark plasma sintering (SPS) of self-propagating high-temperature-synthesis (SHS)-derived Ni-W and Ni-W-2wt%hBN (4:1 molar ratio of metals) powders. The synthesis was carried out from a mixture of NiO and WO3 using Mg + C combined reducers through a thermo-kinetic coupling approach. Experiments performed in the thermodynami...

A strategy of doping by multi-walled carbon nanotubes (MWCNT) to enhance mechanical strength and the electrical conductivity of ceramic fibers has nowadays attracted a great deal of attention for a wide variety of industrial applications. This study focuses on the effect of MWCNTs on rheological properties of metal alkoxide precursors used for the...

In this study, for the first time, hexagonal structured molybdenum aluminosilicide Mo(Si,Al)2 has been successfully in-situ produced with the help of laser powder bed fusion (LPBF) of a blended powder mixture of 90 wt% MoSi2-10 wt.%AlSi10Mg feedstock. Applying triple scanning for upskin changed the top surface morphology, suggesting that applicatio...

Materials based on iron oxide are still the most widely used red pigments. Although the synthetic iron oxide pigment industry has matured, there have been continuous efforts for more circular economy-based methods for the production of pigments. In this study, hematite has been extracted by a hydrothermal method from mill-scale steel slag and the b...

Modeling the self-sustained high-temperature synthesis (SHS) reaction via thermal dilution and transformation of the reaction heterogeneous media into a moderate exothermic one has unlimited potential for designing inorganic powders of a certain morphology beneficial for advanced consolidation. Thermal/inert dilution of the high-exothermic mixtures...

The aim of the study was to investigate effect of Ti/TiB2 composite composition and manufacturing technology parameters on the tribological behaviour of AlCrN coating-composite system. The AlCrN coating was deposited by PVD (Physical Vapour Deposition) method. The composites were manufactured by spark plasma sintering (SPS) from three variants of p...

This paper provides an overview on the recent development of coatings and modified surfaces to minimize wear between contact surfaces in high-temperature working environments. The aim of this work was to study the wear of various types of coatings deposited by the PVD (Physical Vapour Deposition) method on TiB2/Ti composites manufactured by Spark P...

The implementation of a powder bed selective laser processing (PBSLP) technique for bioactive ceramics, including selective laser sintering and melting (SLM/SLS), a laser powder bed fusion (L-PBF) approach is far more challenging when compared to its metallic and polymeric counterparts for the fabrication of biomedical materials. Direct PBSLP can o...

The capability of self-propagating high-temperature synthesis (SHS) to produce powders that are characterized by a high sintering ability, owing to high heating and cooling rates inherent to the exothermic reaction, is of a special interest for the industry. In particular, SHS-derived powders comprise a significant defect concentration in order to...

Interest in luminescent materials has been continuously growing for several decades, looking for the development of new systems with optimized optical properties. Nowadays, research has been focused on the development of materials that satisfy specific market requirements in optoelectronics, radioelectronics, aerospace, bio-sensing, pigment applica...

Mo(Si,Al)2-based composites are promising candidates to be used as heating elements, high temperature coatings and structural materials. In this work, powders mixture of 90 wt.% MoSi2 and 10 wt.% AlSi10Mg was subjected to a laser powder-bed fusion (LPBF) to produce Mo(Si,Al)2-based composites. The effect of process parameters on morphological featu...

Metallic cellular structures with triply periodic minimal surfaces (TPMS) is a great approach to enhance multifunctionality for several engineering disciplines. In the present study, we aimed to generate metal-based Neovious, Schoen I-WP and Schwarz Primitive structures, leveraging on TPMS based design methods. Neovious, Schoen I-WP and Schwarz Pri...

Metallic cellular structures with triply periodic minimal surfaces (TPMS) is a great approach to enhance multifunctionality for several engineering disciplines. In the present study, we aimed to generate metal-based Neovious, Schoen I-WP and Schwarz Primitive structures, leveraging on TPMS based design methods. Neovious, Schoen I-WP and Schwarz Pri...

Functionally gradient materials (FGM) are progressive materials, where the final characteristics are sequentially changing with dimensions. Direct fabrication of functionally gradient Ti6Al4V-TiB composite was performed by spark plasma sintering (SPS) technique. Powder mixtures of six different ratios of Ti-alloy and TiB2 were subjected to sinterin...

The aim of the work was to investigate the adhesion of AlCrN coating deposited by PVD method on TiB 2 /Ti composites manufactured by Spark Plasma Sintering (SPS). The composites were produced from three kinds of mixtures of powders: (1) Ti and TiB 2 , (2) Ti6Al4V and TiB 2 and (3) Ti and B. Each of the mixtures was prepared at 50/50 wt. % ratio of...

Near full dense C40 hexagonal structured Mo(Si 1-x Al x ) 2 -based composite coupons with 7 mm diameter by 7 mm height were prepared by selective laser melting (SLM) of MoSi 2 -30 wt.% AlSi10Mg powder mixture and subjected to isothermal oxidation. As a reference, MoSi 2 bulk sample was prepared by spark plasma sintering (SPS) technique. The quantit...

The remarkable tunability of 2D carbon structures combined with their non-toxicity renders them interesting candidates for thermoelectric applications. Despite some limitations related to their high thermal conductivity and low Seebeck coefficients, several other unique properties of the graphene-like structures could out-weight these weaknesses in...

Graphene is currently attracting attention for radiation absorption particularly at gigahertz and terahertz frequencies. In this work, composites formed by graphene-augmented γ-Al 2 O 3 nanofibers embedded into the α-Al 2 O 3 matrix are tested for X-band absorption efficiency. Composites with 15 and 25 wt % of graphene fillers with shielding effect...

Titanium alloys and composites are of great interest for a wide variety of industrial applications; however, most of them suffer from poor tribological performance, especially at elevated temperatures. In this study, spark plasma sintering was utilized to produce a fully dense and thermodynamically stable TiB–Ti composite with a high content of cer...

The challenge to develop new robust materials inspired the current research on a microwave synthesis and subsequent spark plasma sintering of a lightweight superhard B4C-27wt.%ReB2 ceramic composite. A strategy for fabricating high density parts was developed by sintering the microwave synthesized B4C-ReB2 composite without additives. The bulk mate...

Although Ti-based composites find wide industrial applications, their tribological behaviour, especially at elevated and high temperatures, is not conclusively evaluated. In this work, a sliding wear performance of metal – ceramic composite of 50wt.%Ti–50wt.%TiBw, which were in-situ produced by spark plasma sintering, was studied. Microstructural e...

Despite a high demand for green energy sources, low performance of solid oxide fuel cells (SOFC) hinders the potential for its practical application. Zirconia-graphene composites are promising candidates as solid electrolytes for SOFC enabling efficient heat transfer and effective ion char ge carriers movement. Herein, we report the change in elect...

Nanofibrous substrates and scaffolds are widely being studied as matrices for 3D cell cultures, and disease models as well as for analytics and diagnostic purposes. These scaffolds usually comprise randomly oriented fibers. Much less common are nanofibrous scaffolds made of stiff inorganic materials such as alumina. Well-aligned matrices are a prom...

Advantages and industrial importance of C40 Mo(Si1-x,Alx)2 structure for technical applications have been widely proven. This work details Mo(Si1-x,Alx)2 composite preparation by reactive selective laser melting of (Mo + 2Si) + 30 wt%AlSi10Mg powder. During the process, Mo(Si1-x,Alx)2 (x = 0.33) nucleates and grows as the primary phase alongside in...

Development of new near infrared luminescent (NIR) emitters improves our understanding of their fundamental structure - property relationships. The ability to use eficcient energy transfer to convert ultraviolet or visible light photons to enhance the NIR emission has attracted a great deal of attention in down-conversion applications. Taking advan...

Mo(Si1−x,Alx)2 composites were produced by a pulsed laser reactive selective laser melting of MoSi2 and 30 wt.% AlSi10Mg powder mixture. The parametric study, altering the laser power between 100 and 300 W and scan speed between 400 and 1500 mm·s −1 , has been conducted to estimate the effect of processing parameters on printed coupon samples' qual...

The laser power bed fusion approach has been successfully employed to manufacture Mo(Si,Al)2-based composites through the selective laser melting of a MoSi2-30 wt.% AlSi10Mg mixture for high-temperature structural applications. Composites were manufactured by leveraging the in situ reaction of the components during printing at 150–300 W laser power...

The irruption of additive manufacturing techniques opens the possibility to develop three-dimensional structures with complex geometries and high precision. In the current investigation a newly designed composite combining silicon (30, 40 and 50 wt%) with a bioactive glass and printed into scaffolds was obtained, using a direct selective laser melt...

Selective laser melting was exploited to fabricate lattice structures from TiB2-Ti powder mixtures of high ceramic content (50wt.%TiB2). The lattice structures of 0.8 mm unit cell size were nitridized to produce TiB2-TiN ceramic-ceramic composite. During processing, TiB2 is partially transformed into TiB. Lattice structures of the TiB2-TiB-TiN comp...

Here we report a novel strategy to consolidate layered alumina demonstrating the directional electrical and thermal conductivity. The material was produced via incorporation of alumina nanofibers (20±2 nm in diameter) decorated by several layers of graphene wrapped around longitudinal axes of the fibers. The graphenated fibers, obtained with the he...

Implementation of layered structures with strong nanoscale optimized interfaces, enables engineering of materials with functional properties. In this work, anisotropic functional multi-layered structures are produced by integration of a thin hybrid inter-layer of graphene-augmented-nanofibers/alumina into α-alumina through an ex-situ strategy of pr...

The scaffolds, which morphologically and physiologically mimic natural features of the bone, are of high demand for regenerative medicine. To address this challenge, we have developed innovative bioactive porous silicon- wollastonite substrates for bone tissue engineering. Additive manufacturing through selective laser melting approach has been exp...

One of the main limitations for widespread additive manufacturing is availability and processability of the precursor materials feedstock. For the first time, this study reports the development of a “pomegranate-like” structured TiB2-Si ceramic-metalloid powder feedstock suitable for selective laser melting (SLM) of ceramic-based composite. The pow...

An increasing need in customized ceramics and ceramic-metal composites has driven the development of powders feedstock and procedures for utilization of additive manufacturing for production of mechanically reliable composites. However, processing of materials with a high fraction of ceramic particles is still in its infancy. Herein we report on 3D...

ZrC-TiC-MoSi 2 ceramic composite was consolidated by spark plasma sintering at 1850-1900°C temperature, for 5-10 min of dwell time under 50 MPa of applied pressure. The influence of MoSi2 addition on the mechanical performance and microstructure of ZrC-TiC composite was investigated. Compared with ZrC-TiC, the sinterability of ZrC-TiC-MoSi 2 was im...

Among persistent luminescence materials, one of the most studied systems is SrO-Al2O3 due to its chemical stability and the longest green-afterglow duration. This research is focused on the synthesis of SrAl2O4:Eu,Dy textured layers by the screen-printing. The novelty of the approach is the employment of molten salt to promote crystal growth. The r...

Calcia-alumina binary compounds doped with rare earths and some transition metals cations show persistent luminescence from the visible to the infrared range. Specifically, the blue light can be obtained through the Eu2+ activator center in a potential host, such as dodecacalcium hepta-aluminate (Ca12Al14O33) and monocalcium aluminate (CaAl2O4). By...

Calcia-alumina binary compounds doped with rare earths and some transition metals cations show persistent luminescence from the visible to the infrared range. Specifically, the blue light can be obtained through the Eu2+ activator center in a potential host, such as dodecacalcium hepta-aluminate (Ca12Al14O33) and monocalcium aluminate (CaAl2O4). By...

Utilization of microwave-assisted (MW) synthesis and subsequent spark plasma sintering as an efficient and rapid synthetic route toward the preparation and consolidation of ultrahard B4C boron carbide without additives is reported. Magnesium dodecaboride (MgB12) and carbon were used as raw materials for stepwise MW synthesis of B4C at irradiation p...

In the scope of transition to closed carbon cycle economy hydrogen is becoming a major energy carrier and the development of novel functional materials for its production and storage is of great interest. Liquefied petroleum gas (LPG) is one of the primary options for this purpose due to high energy density and well-developed production and transpo...

Engineered bone tissue or scaffold is a potential alternative to the common use of bone grafts due to limitless supply and no disease transmission. We present a novel way to manufacture the highly efficient bioceramics combining osteoinductive and bioactive elements using additive manufacturing through selective laser melting without polymer based...