Muhamad Yajid - Academia.edu (original) (raw)

Papers by Muhamad Yajid

Research paper thumbnail of Preparation and corrosion resistance of a nanocomposite plasma electrolytic oxidation coating on Mg-1%Ca alloy formed in aluminate electrolyte containing titania nano-additives

Journal of Alloys and Compounds, 2016

Research paper thumbnail of The Effect of Argon Controlled Pre-Oxidation on TGO Formation of NiCoCrAlYTa/YSZ

Key Engineering Materials, 2016

Research paper thumbnail of Synthesis and Characterization of Rice Husk Ash Derived - Silica Aerogel Beads Prepared by Ambient Pressure Drying

Key Engineering Materials, 2016

Research paper thumbnail of Microstructural characterisation of air plasma sprayed nanostructure ceramic coatings on Mg-1%Ca alloys (bonded by NiCoCrAlYTa alloy)

Ceramics International, 2015

Research paper thumbnail of Deposition of duplex MAO layer/ nanostructured titanium dioxide composite coatings on Mg-1%Ca alloy using a combined technique of air plasma spraying and micro arc oxidation

Journal of Alloys and Compounds, 2015

Research paper thumbnail of Fabrication and properties of triplex NiCrAlY/nano Al2O3.13%TiO2/nano TiO2 coatings on a magnesium alloy by atmospheric plasma spraying method

Journal of Alloys and Compounds, 2015

Research paper thumbnail of Improvement of Corrosion Resistance of Binary Mg-Ca Alloys Using Duplex Aluminum-Chromium Coatings

Journal of Materials Engineering and Performance, 2015

Research paper thumbnail of The Role of Nanostructured Al2O3 Layer in Reduction of Hot Corrosion Products in Normal YSZ Layer

ABSTRACT YVO4 crystals and monoclinic ZrO2 are known as hot corrosion products that can considera... more ABSTRACT YVO4 crystals and monoclinic ZrO2 are known as hot corrosion products that can considerably reduce the lifetime of thermal barrier coatings during service. The hot corrosion resistance of two types of air plasma sprayed thermal barrier coating systems was investigated: an Inconel 738/NiCrAlY/YSZ (yttria-stabilized zirconia) and an Inconel 738/NiCrAlY/YSZ/nano-Al2O3 as an outer layer. Hot corrosion test was accomplished on the outer surface of coatings in molten salts (45% Na2SO4 + 55% V2O5) at 1000°C for 52 hour. It was found that nanostructured alumina as outer layer of YSZ/nano-Al2O3 coating had significantly reduced the infiltration of molten salts into the YSZ layer and resulted in lower reaction of fused corrosive salts with YSZ, as the hot corrosion products had been substantially decreased in YSZ/nano-Al2O3 coating in comparison with normal YSZ coating after hot corrosion process.

Research paper thumbnail of Improved Thermally Grown Oxide Scale in Air Plasma Sprayed NiCrAlY/Nano-YSZ Coatings

Oxidation has been considered as one of the principal disruptive factors in thermal barrier coati... more Oxidation has been considered as one of the principal disruptive factors in thermal barrier coating systems during service. So, oxidation behavior of thermal barrier coating (TBC) systems with nanostructured and microstructured YSZ coatings was investigated at 1000 ∘ C for 24 h, 48 h, and 120 h. Air plasma sprayed nano-YSZ coating exhibited a trimodal structure. Microstructural characterization also demonstrated an improved thermally grown oxide scale containing lower spinels in nano-TBC system after 120 h of oxidation. This phenomenon is mainly related to the unique structure of the nano-YSZ coating, which acted as a strong barrier for oxygen diffusion into the TBC system at elevated temperatures. Nearly continues but thinner Al 2 O 3 layer formation at the NiCrAlY/nano-YSZ interface was seen, due to lower oxygen infiltration into the system. Under this condition, spinels formation and growth on the Al 2 O 3 oxide scale were diminished in nano-TBC system compared to normal TBC system.

Research paper thumbnail of Investigation of three steps of hot corrosion process in Y2O3 stabilized ZrO2 coatings including nano zones

Journal of Rare Earths, 2014

Phase transformation of tetragonal ZrO 2 to monoclinic phase and also increment of bond coat oxid... more Phase transformation of tetragonal ZrO 2 to monoclinic phase and also increment of bond coat oxidation kinetic (TGO thickening) can substantially restrict the life time of thermal barrier coating systems (TBCs). So, nanostructured and conventional Y 2 O 3 stabilized ZrO 2 coatings were evaluated in fused V 2 O 5 -Na 2 SO 4 salts during thermal exposure in air. Microstructural characterization showed lower hot corrosion products (monoclinic zirconia, YVO 4 crystals) formation and reduction of TGO thickness in thermal barrier coating system consisting of nanostructured Y 2 O 3 stabilized ZrO 2 (YSZ) top coat. It was found that inhomogeneities, pores and micro-cracks played a principal role in the molten salts infiltration into the YSZ coating during three steps of hot corrosion process. In the nanostructured YSZ coating with tri-model structure, nano zones which surrounded by fully molten parts could fill the aforementioned defects and could act as barrier for the oxygen and corrosive molten salts penetration into the TBC.

Research paper thumbnail of Microstructural consideration on quantitative analysis of thermal treatment: Application to decarburization of steel

Journal of King Saud University - Engineering Sciences, 2013

Abstract Microstructural consideration is implemented in the calculation using commercial finite ... more Abstract Microstructural consideration is implemented in the calculation using commercial finite element analysis to study the effect of thermal treatment for engineering applications. As a typical example, decarburization problem has been studied in the paper. The modeling analysis is then to be compared with the experimental results. The simulation of phase such as singleγ-Fe, mixture of γ-Fe and α-Fe, and the mixture of α-Fe and Fe 3 C are performed by altering the heat treatment temperature. The simulated models have good agreement ...

Research paper thumbnail of Aluminum-Copper Bilayers Thin Films Deposited at Room Temperature by RF Magnetron Sputtering

Applied Mechanics and Materials, 2014

Research paper thumbnail of Energy density mechanics applied to coating blistering problems

Theoretical and Applied Fracture Mechanics, 2011

The use of fracture mechanics outside the area of mechanics, including materials science, is evid... more The use of fracture mechanics outside the area of mechanics, including materials science, is evidence that the concept is capable of handling failures involving almost any types of crack propagations. This paper outlines the simple method on how to use fracture mechanics concepts in coating study by using a concrete example that is easy to follow. The example presented here is the use of fracture mechanics to develop equation governing the blister propagation using the concept pioneered by Sih, the SED concept. Despite being simple, ...

Research paper thumbnail of Plasmon energy chemical phase mapping of reactive multilayers

physica status solidi (RRL) – Rapid Research Letters, 2008

Research paper thumbnail of Reactive Multilayers Examined by HRTEM and Plasmon EELS Chemical Mapping

Microscopy and Microanalysis, 2009

We examine chemical mapping of reaction phases in a Cu-Al multilayer system using low-loss electr... more We examine chemical mapping of reaction phases in a Cu-Al multilayer system using low-loss electron energy loss spectroscopy spectrum imaging and image spectroscopy techniques. The sensitivity of the plasmon peak position and shape to various crystal structures and phases is exploited using postprocessing of spectra into second derivative plasmon maps and line scans. Analytical transmission electron microscopy is complemented by studies of the orientation relationship of the multilayer system using high-resolution electron microscopy of interfaces and selected area diffraction. The techniques have been applied to the Cu-Al multilayer sample and sharply bound epitaxial phases are found, before and after heat treatment.

Research paper thumbnail of Plasmon Resonance Chemical Phase Mapping of Reactive Multilayers

Microscopy and Microanalysis, 2008

Research paper thumbnail of Effect of Y2O3 stabilized ZrO2 coating with tri-model structure on bi-layered thermally grown oxide evolution in nano thermal barrier coating systems at elevated temperatures

Journal of Rare Earths, 2014

ABSTRACT Bi-layered thermally grown oxide (TGO) layer plays a major role in the spallation of Y2O... more ABSTRACT Bi-layered thermally grown oxide (TGO) layer plays a major role in the spallation of Y2O3 stabilized ZrO2 (YSZ) layer form the bond coat in the thermal barrier coating (TBC) systems during oxidation. On the other hand, bi-layered TGO formation and growth in the TBC systems with nanostructured YSZ have not been deeply investigated during cyclic oxidation. Hence, Inconel 738/NiCrAlY/normal YSZ and Inconel 738/NiCrAlY/nano YSZ systems were pre-oxidized at 1000 °C and then subjected to cyclic oxidation at 1150 °C. According to microstructural observations, nanostructured YSZ layer over the bond coat should have less micro-cracks and pinholes, due to the compactness of the nanostructure and the presence of nano zones that resulted in lower O infiltration into the nanothermal barrier coating system, formation of thinner and nearly continuous mono-layered thermally grown oxide on the bond coat during pre-oxidation, lower spinels formation at the Al2O3/YSZ interface and finally, reduction of bi-layered thermally grown oxide thickness during cyclic oxidation. It was found that pre-heat treatment and particularly coating microstructure could influence microstructural evolution (bi-layered TGO thickness) and durability of thermal barrier coating systems during cyclic oxidation.

Research paper thumbnail of Nanoscale sculpting of ferromagnetic structures by electron beam ablation

Journal of Physics: Conference Series, 2010

Abstract. We report an electron beam (e-beam) fabrication method to produce sub-5 nm structures, ... more Abstract. We report an electron beam (e-beam) fabrication method to produce sub-5 nm structures, eg nanohole-arrays, nanojunctions and nanotips inside a TEM. The method is demonstrated using ferromagnetic nickel cross-sectional TEM specimens as well as electrochemically etched nickel tips. Different e-beam shapes and electron guns are compared, including point versus line focus and field-emission versus LaB6 guns. As an extension of this 2-D patterning of nanostructures, a 3-D nanofabrication technique has ...

Research paper thumbnail of Nanostructured reactive metallic multilayers

Journal of Physics: Conference Series, 2010

ABSTRACT Metallic multilayers have been used in cross-sectional TEM specimen geometry to explore ... more ABSTRACT Metallic multilayers have been used in cross-sectional TEM specimen geometry to explore nanostructuring routes using ion and electron beams (top-down) as well as self-organised nanopatterning (bottom-up). Intermetallic alloy formation during heat treatment is studied for binary and ternary layer compositions. A choice of pillars (0D), 1D and 2D layer geometries are used to explore dimensionality effects.

Research paper thumbnail of Heating and EELS experiments of CuAl reactive multilayers

Journal of Physics: Conference Series, 2008

Research paper thumbnail of Preparation and corrosion resistance of a nanocomposite plasma electrolytic oxidation coating on Mg-1%Ca alloy formed in aluminate electrolyte containing titania nano-additives

Journal of Alloys and Compounds, 2016

Research paper thumbnail of The Effect of Argon Controlled Pre-Oxidation on TGO Formation of NiCoCrAlYTa/YSZ

Key Engineering Materials, 2016

Research paper thumbnail of Synthesis and Characterization of Rice Husk Ash Derived - Silica Aerogel Beads Prepared by Ambient Pressure Drying

Key Engineering Materials, 2016

Research paper thumbnail of Microstructural characterisation of air plasma sprayed nanostructure ceramic coatings on Mg-1%Ca alloys (bonded by NiCoCrAlYTa alloy)

Ceramics International, 2015

Research paper thumbnail of Deposition of duplex MAO layer/ nanostructured titanium dioxide composite coatings on Mg-1%Ca alloy using a combined technique of air plasma spraying and micro arc oxidation

Journal of Alloys and Compounds, 2015

Research paper thumbnail of Fabrication and properties of triplex NiCrAlY/nano Al2O3.13%TiO2/nano TiO2 coatings on a magnesium alloy by atmospheric plasma spraying method

Journal of Alloys and Compounds, 2015

Research paper thumbnail of Improvement of Corrosion Resistance of Binary Mg-Ca Alloys Using Duplex Aluminum-Chromium Coatings

Journal of Materials Engineering and Performance, 2015

Research paper thumbnail of The Role of Nanostructured Al2O3 Layer in Reduction of Hot Corrosion Products in Normal YSZ Layer

ABSTRACT YVO4 crystals and monoclinic ZrO2 are known as hot corrosion products that can considera... more ABSTRACT YVO4 crystals and monoclinic ZrO2 are known as hot corrosion products that can considerably reduce the lifetime of thermal barrier coatings during service. The hot corrosion resistance of two types of air plasma sprayed thermal barrier coating systems was investigated: an Inconel 738/NiCrAlY/YSZ (yttria-stabilized zirconia) and an Inconel 738/NiCrAlY/YSZ/nano-Al2O3 as an outer layer. Hot corrosion test was accomplished on the outer surface of coatings in molten salts (45% Na2SO4 + 55% V2O5) at 1000°C for 52 hour. It was found that nanostructured alumina as outer layer of YSZ/nano-Al2O3 coating had significantly reduced the infiltration of molten salts into the YSZ layer and resulted in lower reaction of fused corrosive salts with YSZ, as the hot corrosion products had been substantially decreased in YSZ/nano-Al2O3 coating in comparison with normal YSZ coating after hot corrosion process.

Research paper thumbnail of Improved Thermally Grown Oxide Scale in Air Plasma Sprayed NiCrAlY/Nano-YSZ Coatings

Oxidation has been considered as one of the principal disruptive factors in thermal barrier coati... more Oxidation has been considered as one of the principal disruptive factors in thermal barrier coating systems during service. So, oxidation behavior of thermal barrier coating (TBC) systems with nanostructured and microstructured YSZ coatings was investigated at 1000 ∘ C for 24 h, 48 h, and 120 h. Air plasma sprayed nano-YSZ coating exhibited a trimodal structure. Microstructural characterization also demonstrated an improved thermally grown oxide scale containing lower spinels in nano-TBC system after 120 h of oxidation. This phenomenon is mainly related to the unique structure of the nano-YSZ coating, which acted as a strong barrier for oxygen diffusion into the TBC system at elevated temperatures. Nearly continues but thinner Al 2 O 3 layer formation at the NiCrAlY/nano-YSZ interface was seen, due to lower oxygen infiltration into the system. Under this condition, spinels formation and growth on the Al 2 O 3 oxide scale were diminished in nano-TBC system compared to normal TBC system.

Research paper thumbnail of Investigation of three steps of hot corrosion process in Y2O3 stabilized ZrO2 coatings including nano zones

Journal of Rare Earths, 2014

Phase transformation of tetragonal ZrO 2 to monoclinic phase and also increment of bond coat oxid... more Phase transformation of tetragonal ZrO 2 to monoclinic phase and also increment of bond coat oxidation kinetic (TGO thickening) can substantially restrict the life time of thermal barrier coating systems (TBCs). So, nanostructured and conventional Y 2 O 3 stabilized ZrO 2 coatings were evaluated in fused V 2 O 5 -Na 2 SO 4 salts during thermal exposure in air. Microstructural characterization showed lower hot corrosion products (monoclinic zirconia, YVO 4 crystals) formation and reduction of TGO thickness in thermal barrier coating system consisting of nanostructured Y 2 O 3 stabilized ZrO 2 (YSZ) top coat. It was found that inhomogeneities, pores and micro-cracks played a principal role in the molten salts infiltration into the YSZ coating during three steps of hot corrosion process. In the nanostructured YSZ coating with tri-model structure, nano zones which surrounded by fully molten parts could fill the aforementioned defects and could act as barrier for the oxygen and corrosive molten salts penetration into the TBC.

Research paper thumbnail of Microstructural consideration on quantitative analysis of thermal treatment: Application to decarburization of steel

Journal of King Saud University - Engineering Sciences, 2013

Abstract Microstructural consideration is implemented in the calculation using commercial finite ... more Abstract Microstructural consideration is implemented in the calculation using commercial finite element analysis to study the effect of thermal treatment for engineering applications. As a typical example, decarburization problem has been studied in the paper. The modeling analysis is then to be compared with the experimental results. The simulation of phase such as singleγ-Fe, mixture of γ-Fe and α-Fe, and the mixture of α-Fe and Fe 3 C are performed by altering the heat treatment temperature. The simulated models have good agreement ...

Research paper thumbnail of Aluminum-Copper Bilayers Thin Films Deposited at Room Temperature by RF Magnetron Sputtering

Applied Mechanics and Materials, 2014

Research paper thumbnail of Energy density mechanics applied to coating blistering problems

Theoretical and Applied Fracture Mechanics, 2011

The use of fracture mechanics outside the area of mechanics, including materials science, is evid... more The use of fracture mechanics outside the area of mechanics, including materials science, is evidence that the concept is capable of handling failures involving almost any types of crack propagations. This paper outlines the simple method on how to use fracture mechanics concepts in coating study by using a concrete example that is easy to follow. The example presented here is the use of fracture mechanics to develop equation governing the blister propagation using the concept pioneered by Sih, the SED concept. Despite being simple, ...

Research paper thumbnail of Plasmon energy chemical phase mapping of reactive multilayers

physica status solidi (RRL) – Rapid Research Letters, 2008

Research paper thumbnail of Reactive Multilayers Examined by HRTEM and Plasmon EELS Chemical Mapping

Microscopy and Microanalysis, 2009

We examine chemical mapping of reaction phases in a Cu-Al multilayer system using low-loss electr... more We examine chemical mapping of reaction phases in a Cu-Al multilayer system using low-loss electron energy loss spectroscopy spectrum imaging and image spectroscopy techniques. The sensitivity of the plasmon peak position and shape to various crystal structures and phases is exploited using postprocessing of spectra into second derivative plasmon maps and line scans. Analytical transmission electron microscopy is complemented by studies of the orientation relationship of the multilayer system using high-resolution electron microscopy of interfaces and selected area diffraction. The techniques have been applied to the Cu-Al multilayer sample and sharply bound epitaxial phases are found, before and after heat treatment.

Research paper thumbnail of Plasmon Resonance Chemical Phase Mapping of Reactive Multilayers

Microscopy and Microanalysis, 2008

Research paper thumbnail of Effect of Y2O3 stabilized ZrO2 coating with tri-model structure on bi-layered thermally grown oxide evolution in nano thermal barrier coating systems at elevated temperatures

Journal of Rare Earths, 2014

ABSTRACT Bi-layered thermally grown oxide (TGO) layer plays a major role in the spallation of Y2O... more ABSTRACT Bi-layered thermally grown oxide (TGO) layer plays a major role in the spallation of Y2O3 stabilized ZrO2 (YSZ) layer form the bond coat in the thermal barrier coating (TBC) systems during oxidation. On the other hand, bi-layered TGO formation and growth in the TBC systems with nanostructured YSZ have not been deeply investigated during cyclic oxidation. Hence, Inconel 738/NiCrAlY/normal YSZ and Inconel 738/NiCrAlY/nano YSZ systems were pre-oxidized at 1000 °C and then subjected to cyclic oxidation at 1150 °C. According to microstructural observations, nanostructured YSZ layer over the bond coat should have less micro-cracks and pinholes, due to the compactness of the nanostructure and the presence of nano zones that resulted in lower O infiltration into the nanothermal barrier coating system, formation of thinner and nearly continuous mono-layered thermally grown oxide on the bond coat during pre-oxidation, lower spinels formation at the Al2O3/YSZ interface and finally, reduction of bi-layered thermally grown oxide thickness during cyclic oxidation. It was found that pre-heat treatment and particularly coating microstructure could influence microstructural evolution (bi-layered TGO thickness) and durability of thermal barrier coating systems during cyclic oxidation.

Research paper thumbnail of Nanoscale sculpting of ferromagnetic structures by electron beam ablation

Journal of Physics: Conference Series, 2010

Abstract. We report an electron beam (e-beam) fabrication method to produce sub-5 nm structures, ... more Abstract. We report an electron beam (e-beam) fabrication method to produce sub-5 nm structures, eg nanohole-arrays, nanojunctions and nanotips inside a TEM. The method is demonstrated using ferromagnetic nickel cross-sectional TEM specimens as well as electrochemically etched nickel tips. Different e-beam shapes and electron guns are compared, including point versus line focus and field-emission versus LaB6 guns. As an extension of this 2-D patterning of nanostructures, a 3-D nanofabrication technique has ...

Research paper thumbnail of Nanostructured reactive metallic multilayers

Journal of Physics: Conference Series, 2010

ABSTRACT Metallic multilayers have been used in cross-sectional TEM specimen geometry to explore ... more ABSTRACT Metallic multilayers have been used in cross-sectional TEM specimen geometry to explore nanostructuring routes using ion and electron beams (top-down) as well as self-organised nanopatterning (bottom-up). Intermetallic alloy formation during heat treatment is studied for binary and ternary layer compositions. A choice of pillars (0D), 1D and 2D layer geometries are used to explore dimensionality effects.

Research paper thumbnail of Heating and EELS experiments of CuAl reactive multilayers

Journal of Physics: Conference Series, 2008