Farhad Saba

Shanghai Jiao Tong University | SJTU · State Key Laboratory of Metal Matrix Composites

Achieving a uniform dispersion and high efficiency in metal matrix nanocomposites (MMNCs) with a high-content of nano-reinforcements is still a challenging issue. Flake dispersion, a fabrication process combining flake powder metallurgy with high-shear dispersion, is proposed to alleviate the problem. In this regard, flake Al powders with a large s...

Ultra-short carbon nanotubes (CNTs) have many unique features but cutting CNTs to below 100 nm is still challenging. Herein, we explore a new high-speed shearing process based on the shearing force-assisted compressing force process to cut CNTs, which is different from the conventional mechanical process based on compressing force. The optimal bala...

To overcome strength-ductility trade-off in particulate metal matrix composites (PRMMCs), we developed a novel and controllable strategy, for the first time, via a combination of micro/nano-reinforcements and ultrafine/coarse-grained (UFG/CG) matrices. A powder assembly was developed to fabricate micro B4Cp/6061Al composites, which features UFG/CG...

Marine fouling is a worldwide challenge with huge damages on industrial structures, side effects on economics of industries, and environmental and safety-related hazards. Different approaches have been used for combating fouling in the marine environment. Meanwhile, nanocomposite polymer coatings are a novel generation of antifouling coatings with...

Controlling the location of carbon nanotubes (CNTs) within Al matrix is still challenging. To clarify the factors/mechanisms affecting the spatial distribution of CNTs, Short and Long CNTs were chosen as reinforcements, and their locations were characterized after ball milling, sintering and hot extrusion in order to study the effect of length-scal...

Ti3AlC2 MAX phase ceramic particles were used to reinforce Ti-6.5Al-2Zr-1Mo-1 V (TA15) alloy. The composites with a network architecture were prepared by low-energy ball milling (LEBM) and spark plasma sintering techniques. The effects of Ti3AlC2 content (0.5–2.0 wt%) on the microstructure, mechanical properties and wear resistance of the composite...

A smart approach was adopted to fabricate a heterogeneous 1.5 wt.% CNT/Al matrix possessing enhanced mechanical properties. The heterostructured-composite showed an excellent ultimate compressive strength of 372.19 MPa, which was approximately 33% and 76% higher than that of its homogeneous counterpart (279.83 MPa) and the monolithic Al (211.56 MPa...

In the present study, we reported a powder processing technique for fabricating a heterogeneous AlSi10Mg matrix reinforced by CNTs with enhanced comprehensive mechanical properties. The as-designed composite with 2 wt.% CNT exhibited excellent compressive yield strength of 211 MPa, which was 384% higher than that of the as-received AlSi10Mg (44 MPa...

Graphene (GR) was selected as a reinforcing phase to strengthen Ti6Al4V (TC4) alloy with incorporation of TiC nanoparticles at the interface of GR/Ti to reduce the interfacial reaction. The GR/TiC-TC4 composites with 3D-network architecture were fabricated by 3D dynamic mixing and spark plasma sintering (SPS) techniques. Experimental results showed...

This research is going to propose a simple, effective, but smart and controllable approach by introducing a novel microstructural design to produce hybrid-Al composite with multi-scale architecture and evaluate its effects on the micro- and macro-mechanical properties of the composite. In this regard, the influence of microstructural features on th...

The inherent defects of traditional graphite bulks, such as microcracks and brittleness, have a severe impact on their application performances. The introduction of graphene (Gr) into graphite materials is considered as an effective strategy to improve their properties. Herein, Gr reinforced graphite bulk composites with nanodiamonds (NDs) as a mat...

Novel three-dimensional (3D) hierarchical macro- to nano-porous titanium (Ti) and TiMo alloys with sufficient compressive strength (CS) were prepared using NaCl spacer and dealloying methods. The dealloying process was implemented by the heat treatment of TiCu and TiMoCu master alloys in Mg powders. The 3D-hierarchical porous structures were compos...

Novel three-dimensional (3D) hierarchical macro- to nano-porous titanium (Ti) and TiMo alloys with sufficient compressive strength (CS) were prepared using NaCl spacer and dealloying methods. The dealloying process was implemented by the heat treatment of TiCu and TiMoCu master alloys in Mg powders. The 3D-hierarchical porous structures were compos...

Novel three-dimensional (3D) hierarchical macro- to nano-porous titanium (Ti) and TiMo alloys with sufficient compressive strength (CS) were prepared using NaCl spacer and dealloying methods. The dealloying process was implemented by the heat treatment of TiCu and TiMoCu master alloys in Mg powders. The 3D-hierarchical porous structures were compos...

Nanocomposite coatings based on adding inorganic nanofillers in polymer matrix are a new class of corrosion protection methods which show superior corrosion resistance and mechanical performance compared to conventional composite coatings. Inorganic nanomaterials such as metal nanopowders, metal oxides, nano-glass flakes, nitrides and carbides, and...

Particulate reinforced metal matrix composites (PRMMCs) have a great potential for many structural and functional applications including defense, aerospace and automotive industries due to their high specific strength and modulus, low thermal expansion as well as multifunctional properties. However, incorporating micron-sized ceramic particles in t...

Nanodiamonds were annealed in a spark plasma sintering (SPS) furnace to synthesize onion-like carbon (OLC) powder, and thereafter, OLC-reinforced titanium (Ti) matrix composites with 0.1-1.0 wt. % OLCs were fabricated through SPS. Experimental results showed that OLCs were partially in-situ reacted with the Ti matrix forming nano- to submicron TiC...

Defective nanotube and disarrays of CNT walls (Intersecting CNT walls): The defective structures such as inter-wall sp3 bridging in CNTs could enhance their inter-wall shear strength, improving the load transferring from the surface to the inner walls.

NDs structural changes under pulsed DC field with pressure and without pressure

Reinforcement size dependence of mechanical properties and strengthening mechanisms in diamond reinforced titanium metal matrix composites:Diamond particulates-reinforced titanium matrix composites were fabricated by spark plasma sintering (SPS) technique at different reinforcement sizes of 5, 100 and 200 nm as well as 3 μm. Microstructure and comp...

Linking the inner-walls of MWCNTs through TiC nanolumps by using rapid SPS mehod

Formation of TiC-modified CNTs as well as TiC nanotubes and TiC nanorods by a novel pressureless-SPS technique at 1050 C after just 5 minutes

TiC nanorods were formed through pressureless spark plasma sintering of Ti+crushed CNT/raw CNT

Ni–20Cr alloy with Ni-coated and uncoated hybrid particle size (nano- and micron) ZrO2 reinforcements (11, 15 and 19 wt %) were used to prepare oxide dispersion strengthening (ODS) superalloy by powder metallurgy. The resultant composite powders were consolidated through spark plasma sintering (SPS) method. The effect of Ni-coating and the size of...

Effect of CNT defect sites on the formation of ceramic nanoparticles; Some defects including open tips, bamboo defects and so on...

TiC nanolumps can link the inner-walls of MWCNTs, making them contributed to the strengthening mechanisms

Among the composite materials, the endeavors for developing light-weight metal matrix composites (MMCs) with an excellent performance have been conducted for structural applications...

Achieving a uniform dispersion of carbon nanotubes (CNTs) in metal matrix composites (MMCs) is a vital prerequisite for enhancing the mechanical properties of the samples. In this work, a novel strategy called little by little (LbL) adding was successfully adopted in order to achieve a uniform dispersion of CNTs. The Al composite powders reinforced...

The pulsed DC field-induced thermal stability of nanodiamonds (NDs) and their transformation to carbon onions lack detailed understanding. In this study, a comprehensive study was conducted, analyzing the thermal stability of NDs and the optimum conditions required for the formation of carbon onions, using spark plasma sintering (SPS) utilizing ON-...

This book describes spark plasma sintering (SPS) in depth. It addresses fundamentals and material-specific considerations, techniques, and applications across a broad spectrum of materials. The book highlights methods used to consolidate metallic or ceramic particles in very short times. It highlights the production of complex alloys and metal matr...

A novel strategy called LbL was successfully adopted in order to achieve a uniform dispersion of carbon nanotubes (CNTs) in Al matrix composite with intact structures...

The aim of this work was to perform surface modification of carbon nanotubes (CNTs) in order to utilize them as reinforcements into aluminum matrix nanocomposites. The surface modification of carbon nanotubes was carried out through a three-stage process. At stage 1, mechanical crushing of Ti and MWCNTs was performed via ultrasonication and wet mil...

Diamond particulates reinforced titanium matrix composites (TiMMCs) were fabricated by spark plasma sintering technique at different reinforcement sizes of 5, 100, 200 nm and 3 μm. The dependence of reinforcement size on the mechanical and tribological properties in the TiMMCs was studied, paying particular attention to the nanoscale effects. The e...

نانولوله‌های کربنی چند جداره به دلیل خواص مکانیکی بسیارخوب به عنوان یک تقویت‌کننده‌ی مناسب برای کامپوزیت‌های زمینه پلیمری، سرامیکی و فلزی در نظرگرفته می‌شوند. دراین تحقیق، اثرروش پلاسمای جرقه‌ای (SPS) و درصد وزنی نانولوله کربنی روی ریزساختار و خواص مکانیکی نانوکامپوزیت Al/CNT مورد بررسی قرار گرفت. نانوکامپوزیت آلومینیوم تقویت‌شده حاوی درصدهای متفاو...

The aim of this work was to perform surface modification of carbon nanotubes (CNTs) in order to utilize them as reinforcements into aluminum matrix nanocomposites. The surface modification of carbon nanotubes was carried out through a three-stage process. At stage (I), mechanical crushing of Ti and MWCNTs was performed via ultrasonication and wet m...

Aluminum-matrix composites dual-reinforced by TiC/CNTs were fabricated using a combination of mechanical milling and spark plasma sintering (SPS) techniques. Composition, structure and morphology of the samples were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM) and high resolution transmission electr...

In the present study, single-phase TiC nanotubes and nanorods were synthesized by a novel pressureless spark plasma sintering (SPS) technique using carbon nanotubes (CNTs) and titanium powders at 1050 °C for 5 min. Moreover, formation mechanism of the resultant nanomaterials was clarified in detail. X-ray diffraction (XRD), transmission electron mi...

Carbon nanotubes (CNTs) have created an enormous amount of excite- ment in research laboratories across the world due to their extraordinary mechanical properties and unique electronic properties. This is evident from the exponential growth over the last decade in journal publications and conference presentations on all subjects related to CNTs....

In this study, a novel method was developed for surface modification of CNTs through a pressureless spark plasma sintering. TiC:CNT mixing ratio was changed in the range of 1:2–5:2 to find the optimum ratio. Thereafter, by changing the amount of nanotubes in the optimal mixing ratio (4:2), the effect of modified-CNT content (0.5–5 wt%) on the mecha...

The aim of this work is to identify relationships between the input variables and the process responses and to develop predictive models that could be used in the design of coating AISI D2 steel substrate with TiC powder by a ball milling process. A ‘one-factor design’ combining a response surface methodology with a modified cubic model was employe...

We present a novel route to fabricate 3D nanoporous α-Ti foams by dealloying of TiCu master alloy in solid state using Mg powders. Pure open-cell nanoporous α-Ti foams are fabricated with BET surface area of 34.4 ± 0.8 m²/g and pore size in the range of 2–50 nm. The dealloying using powders is a solid state chemical reaction process to form Cu2Mg p...

Carbon nanotubes (CNTs), generally do not completely impart their exceptional properties in aluminum-matrix composites because of the poor interfacial bonding between these nanofillers and the matrix. In the present study, surface modification of CNTs with nanocrystalline titanium carbide (TiC) was performed through a pressureless-spark plasma sint...

In this work, two methods including mechanical milling (MM) and pulsed laser deposition (PLD) followed by MM were employed for coating of Ti samples by TiC powder. The objective of the present study is finding the relationships between the input variables and the process responses as well as making the predictive model used in the design of TiC coa...

Multiwalled carbon nanotubes (MWCNTs) were surface modified with titanium carbide (TiC) nanocrystalline particles by a novel pressureless spark plasma sintering method. The microstructure and properties of the nano-TiC modified MWCNTs were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, thermal gr...

In this work, a novel surface coating technique, namely pulsed laser deposition (PLD), along with a high-energy mechanical milling (MM) methods were used to deposit well-bonded TiC coatings on a titanium grade (II) substrate. For this reason, TiC particles were coated on titanium plates, with and without PLD layer, using ball milling process at dif...

In this work, a novel surface coating technique, namely pulsed laser deposition (PLD), along with a highenergy mechanical milling (MM) methods were used to deposit well-bonded TiC coatings on a titanium grade (II) substrate. For this reason, TiC particles were coated on titanium plates, with and without PLD layer, using ball milling process at diff...

In the present study, mechanical alloying (MA) was used to deposit well-bonded TiC coatings on D2 steel substrates from titanium and carbon powders. The effect of milling duration and ball-to-powder mass ratio (BPMR), as well as the effect of substrate hardening has been investigated. Microstructure of the coated samples was studied by scanning ele...

In this study TiC coating was formed on AISI-D2 steel by mechanical milling. In this regard, steel sample, balls and the powder were placed within a milling vial. Ball milling were carried out with annealed and quench-tempered samples using TiC powder having particle sizes of 44 and 200 μm for 5, 10, 15, 20, 50 and 100 h. During milling treatment,...