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1
DEPARDIEU, GILLES. "Proprietes optiques des nanocomposites al-aln." Paris 6, 1995. http://www.theses.fr/1995PA066580.
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Le developpement rapide de nouveaux materiaux composites est une occasion de mieux comprendre leur interaction avec les rayonnements electromagnetiques. De nombreuses applications en decoulent comme la realisation de capteurs selectifs, de revetements pour des applications esthetiques ou de furtivite. Cette etude presente une synthese des modeles anciens jusqu'aux plus modernes des proprietes optiques des materiaux heterogenes desordonnes. En particulier, sont discutees l'application des theories du groupe de renormalisation et de la percolation, ainsi que les differentes variantes de theories de milieux effectifs. L'etude est menee sur un composite original: l'al-aln. L'importance de la morphologie 3d est soulignee, et celle-ci est prise en compte dans le modele propose, a l'aide d'outils de traitement d'image et de la programmation hyperparallele. Une comparaison theorie - experience permet enfin de valider le nouveau modele de renormalisation optique 3d
2
BANAL, RYAN GANIPAN. "MOVPE Growth of AlN and AlGaN/AlN Quantum Wells and their Optical Polarization Properties." 京都大学 (Kyoto University), 2009. http://hdl.handle.net/2433/78005.
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TABARY, PATRICK. "Etude du diagramme de phases al#2o#3-aln." Paris 11, 1997. http://www.theses.fr/1997PA112219.
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Cette etude du diagramme al#2o#3-aln pour des compositions moyennes comprises entre 0 et 50%mol aln a ete realisee par plusieurs techniques incluant le dosage par microsonde de castaing, la microscopie electronique en transmission, la diffraction des neutrons et l'analyse thermique differentielle a haute temperature. Les principaux elements du nouveau diagramme sont les temperatures de fusion des phases spinelles (entre 2045 et 2085c), la composition du point eutectique 12h+liquide+gamma-alon (40%mol aln) et le domaine de stabilite en composition de la phase phi'-alon au voisinage de la fusion (de 10 a 20%mol aln). Les temperatures d'equilibre des polytypes 21r, 12h et 27r ont ete reevaluees et une nouvelle phase du systeme quaternaire al#2o#3-aln-al#4c#3 a ete decrite. A l'aide de la met, de la diffraction des r. X et des neutrons nous avons determine les mailles, la position des lacunes et les maclages des phases modulees phi' et delta-alon, et confirme l'existence de domaines d'antiphase. La modelisation thermodynamique du diagramme a l'aide du programme thermocalc a ete realisee apres description des sous-reseaux des phases phi' et delta-alon et en introduisant les enthalpies de fusion des phases spinelles obtenues par atd. L'evaluation des contraintes residuelles dans le materiau a montre l'influence de la relaxation plastique au cours du refroidissement. Le procede industriel de nitruration de l'aluminium en presence d'alumine a ete reproduit en laboratoire et a une echelle semi-industrielle. Les temperatures d'initiation de la reaction, les temperatures maximales atteintes et les taux de nitruration ont ainsi pu etre determines.
4
Troadec, Carole. "Composite à matrice métallique Al-AlN : de la poudre au matériau." Grenoble INPG, 1996. http://www.theses.fr/1996INPG4205.
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Cette etude s'inscrit dans le cadre de l'elaboration de composites a matrice metallique aluminium/nitrure d'aluminium, par metallurgie des poudres. Deux types de poudres sont utilisees: une poudre dite composite synthetisee par nitruration directe de l'aluminium par l'azote et une poudre dite melange obtenue a partir d'un melange de poudres commerciales elementaires aluminium et nitrure d'aluminium. Ces deux types de poudres subissent un broyage hautement energetique par melangeur planetaire sous argon, puis sont frittes par compression a chaud en phase solide. La microstructure de ces materiaux, etudiee en met et nanoanalyse edx, est relativement heterogene, constituee de zones denses polycristallines et de zones a forte porosite constituees de nanocristaux. La taille de ces zones microporeuses est superieure dans les materiaux melanges et varie en fonction du taux de nitrure d'aluminium et du temps de broyage. Les zones denses sont composees de grains d'aluminium entoures de nanocristaux de nitrure d'aluminium, avec des aiguilles d'alumine et quelques cristaux d'oxynitrure d'aluminium. L'ordre de grandeur des cristaux (<1 m) est confirme par diffraction des rayons x. Les proprietes physico-chimiques (coefficient de dilatation, conductivites thermique et electrique) et mecaniques (durete, module de young, limite d'elasticite, contrainte a la rupture) different en fonction du type des poudres de depart et evoluent avec la teneur en aln. Le comportement des deux types de materiaux differe egalement en usure et en corrosion. Ces nouveaux materiaux ont dans l'ensemble, a teneur en renfort similaire, des proprietes equivalentes a celles des materiaux al/sic ou al/al#2o#3
5
Řihák, Radek. "Depozice Al a AlN ultratenkých vrstev na křemíkový a grafenový substrát." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254277.
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This master's thesis deals with preparation and analysis of ultrathin films of aluminum and aluminum nitride. Films were prepared by effusion cells designed in previous bachelor's thesis. Cell construction and testing is included in this thesis. Behavior of aluminum on silicon dioxide, silicon and graphene was studied. Preparation of aluminum nitride by effusion cell and nitrogen ion source is described.
6
Nepal, Neeraj. "Deep ultraviolet photoluminescence studies of Al-rich AlGaN and AlN epilayers and nanostructures." Diss., Manhattan, Kan. : Kansas State University, 2006. http://hdl.handle.net/2097/221.
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Al, Tahtamouni Talal Mohammed Ahmad. "MOCVD growth and characterization of al-rich ALN/ALGAN epilayers and quantum wells." Diss., Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/431.
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8
Xiao, Xiaoling, and S3060677@student rmit edu au. "Characterization of nano-structured coatings containing aluminium, aluminium-nitride and carbon." RMIT University. Applied Sciences, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20081217.100453.
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There is an every increasing need to develop more durable and higher performing coatings for use in a range of products including tools, devices and bio-implants. Nano-structured coatings either in the form of a nanocomposite or a multilayer is of considerable interest since they often exhibit outstanding properties. The objective of this thesis was to use advanced plasma synthesis methods to produce novel nano-structured coatings with enhanced properties. Coatings consisting of combinations of aluminum (Al), aluminum nitride (AlN) and amorphous carbon (a-C) were investigated. Cathodic vacuum arc deposition and unbalanced magnetron sputtering were used to prepare the coatings. By varying the deposition conditions such as substrate bias and temperature, coatings with a variety of microstructures were formed. A comprehensive range of analytical methods have been employed to investigate the stoichiometry and microstructure of the coatings. These include Transmission Electron Microscopy (TEM), Scanning Transmission Electron Microscopy (STEM), Electron Energy Loss Spectroscopy, Auger Electron Spectroscopy, X-ray diffraction and Raman spectroscopy. In addition to the investigation of microstructure, the physical properties of the coatings were measured. Residual stress has been recognized as an important property in the study of thin film coatings since it can greatly affect the quality of the coatings. For this reason, residual stress has been extensively studied here. Hardness measurements were performed using a nano indentation system, which is sensitive to the mechanical properties of thin films. This thesis undertook the most comprehensive investigation of the Al/AlN multilayer system. A major finding was the identification of the conditions under which layers or nanocomposite form in this system. A model was developed based on energetics and diffusion limited aggregation that is consistent with the experimental data. Multilayers of a-C and Al were also found to form nanocomposites. No hardness enhancement as a function of layer thickness or feature size was observed in either the Al/AlN or a-C/a-C systems. It was found that the most important factor which determines hardness is the intrinsic stress, with films of high compressive stress exhibiting the highest hardness. Nano-structured multilayers of alternating high and low density a-C were investigated. For a-C multilayers prepared using two levels of DC bias, evidence of ion beam induced damage was observed at the interfaces of both the low and high density layers. In addition, the structure of the high density (ta-C, known as tetrahedral amorphous carbon) layers was found to be largely unchanged by annealing. These results extend our understanding of how a-C form from energetic ion beams and confirms the thermal stability of ta-C in a multilayer. This thesis also presented the first attempt to synthesis a-C multilayered films with a continuously varying DC bias in sinusoidal pattern. The resulting films were shown to have a structurally graded interface between layers and verified that ion energy and stress are the most important factors which determine the structure of a-C films.
9
Ive, Tommy. "Growth and investigation of AlN/GaN and (Al,In)N/GaN based Bragg reflectors." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=978915607.
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Burghartz, S. [Verfasser]. "Thermophysikalische Eigenschaften von α-Al₂O₃, MgAl₂O₄ und AlN im Tieftemperaturbereich / S. Burghartz." Karlsruhe : KIT-Bibliothek, 1995. http://d-nb.info/1099432189/34.
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Ive, Tommy. "Growth and investigation of AlN/GaN and (Al,In)N/GaN based Bragg reflectors." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2006. http://dx.doi.org/10.18452/15395.
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Die Synthese von AlN/GaN- und (Al,In)N/GaN-Braggreflektoren wird untersucht. Die Strukturen wurden mittels plasmaunterstützter Molekularstrahlepitaxie auf 6H-SiC(0001)-Substraten abgeschieden. Ferner wurde der Einfluß der Si-Dotierung auf die Oberflächenmorphologie sowie die strukturellen und elektrischen Eigenschaften der AlN/GaN-Braggreflektoren untersucht. Es wurden rißfreie Braggreflektoren mit einer hohen Reflektivität (R>99%) und einem bei 450 nm zentrierten Stopband erhalten. Die Si-dotierten Strukturen weisen eine ohmsche I-V-Charakteristik im gesamten Meßbereich sowie einen spezifischen Widerstand von 2-4 mOhmcm2 auf. Die Ergebnisse der (Al,In)N-Wachstumsversuche wurden in einem Phasendiagramm zusammengefaßt, welches den optimalen Parameterraum für (Al,In)N klar aufzeigt.We study the synthesis of AlN/GaN and (Al,In)N/GaN Bragg reflectors. The structures were grown by plasma-assisted molecular beam epitaxy (MBE) on 6H-SiC(0001) substrates. In addition, we study the impact of Si-doping on the surface morphology and the structural and electrical properties of the AlN/GaN Bragg reflectors. Crack-free and high-reflectance (R>99%) Bragg reflectors were achieved with a stopband centered at 450 nm. The Si-doped structures exhibit ohmic I-V behavior in the entire measurement range. The specific series resistance is 2-4 mOhmcm2. The results of the (Al,In)N growth experiments are summarized in a phase diagram which clearly shows the optimum growth window for (Al,In)N.
12
Rudolph, Pascale. "Physikalische Chemie der Laser-Material-Wechselwirkung mit Ba-Al-Borosilikatglas, AlN, SiC, SiC-TiC-TiB2." [S.l.] : [s.n.], 2001. http://www.diss.fu-berlin.de/2002/31/index.html.
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Sperisen, Thierry. "Composites Al₂O₃/TiN préparés à partir de mélanges AlN/TiO₂ : mécanismes de la réaction et propriétés /." Lausanne, 1990. http://library.epfl.ch/theses/?nr=846.
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14
Granon, Arielle. "Étude du frittage réactif dans le système Al₂O₃-AlN-MgO : application à l'élaboration d'une céramique spinelle oxynitrurée transparente." Grenoble INPG, 1994. http://www.theses.fr/1994INPG4202.
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La céramique spinelle oxynitrure d'aluminium et de magnésium est obtenue transparente dans le visible et l'infra-rouge par frittage réactif d'un mélange de poudres d'alumine, nitrure d'aluminium et oxyde de magnésium. L'oxynitrure d'aluminium et de magnésium se forme par réaction en phase solide entre une structure spinelle hôte (aluminate de magnésium ou oxynitrure d'aluminium) et du nitrure d'aluminium ou de l'oxyde de magnésium. Son apparition est généralement effective au dessus de 1350 0c mais peut être observée a 1200c (par réaction oxyde de magnésium oxynitrure d'aluminium). La présence de nitrure d'aluminium induit le départ d'espèces gazeuses magnésium et azote par réaction avec l'oxyde de magnésium ou l'aluminate de magnésium. Ces départs affaiblissent les teneurs en azote et de magnésium de la solution solide et modifient la microstructure. Mais ce départ peut être limite en utilisant un environnement stabilisateur constitue d'oxyde de magnésium et de nitrure d'aluminium. La microstructure des matériaux est étroitement liée aux matières premières. Un caractère binodal est note lorsque la structure hôte spinelle aluminate de magnésium est présente au départ alors qu'une taille de grains fins et homogènes est observée si le spinelle hôte est forme in situ. Des recuits successifs en dessous de 1750c ne modifient que légèrement la taille des grains. Une post compression isostatique à chaud est nécessaire pour éliminer la fine porosité résiduelle et l'évolution microstructurale différé selon les matières premières, les conditions de pré-traitement par frittage sous charge et la température de post compression isostatique à chaud
15
石井, 良太. "GaN およびAlNの励起子変形ポテンシャルの同定と(Al,Ga)N系歪量子構造の物性予測." 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/174940.
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16
Yu, Kuan-Hung. "Optical Spectroscopy of GaN/Al(Ga)N Quantum Dots Grown by Molecular Beam Epitaxy." Thesis, Department of Physics, Chemistry and Biology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-19821.
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GaN quantum dots grown by molecular beam epitaxy are examined by micro-photoluminescence. The exciton and biexciton emission are identified successfully by power-dependence measurement. With two different samples, it can be deduced that the linewidth of the peaks is narrower in the thicker deposited layer of GaN. The size of the GaN quantum dots is responsible for the binding energy of biexciton (EbXX); EbXX decreases with increasing size of GaN quantum dots. Under polarization studies, polar plot shows that emission is strongly linear polarized. In particular, the orientation of polarization vector is not related to any specific crystallography orientation. The polarization splitting of fine-structure is not able to resolve due to limited resolution of the system. The emission peaks can be detected up to 80 K. The curves of transition energy with respect to temperature are S-shaped. Strain effect and screening of electric field account for blueshift of transition energy, whereas Varshni equation stands for redshifting. Both blueshifting and redshifting are compensated at temperature ranging from 4 K to 40 K.
17
Widmann, Frédéric. "Epitaxie par jets moléculaires de GaN, AlN, InN et leurs alliages : physique de la croissance et réalisation de nanostructures." Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10234.
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Ce travail a porte sur la croissance epitaxiale des nitrures d'elements iii gan, aln, et inn, en utilisant l'epitaxie par jets moleculaires assistee par plasma d'azote. Nous avons optimise les premiers stades de la croissance de gan ou aln sur substrat al#2o#3 (0001). Le processus utilise consiste a nitrurer la surface du substrat a l'aide du plasma d'azote, afin de la transformer en aln, puis a faire croitre une couche tampon d'aln ou de gan a basse temperature, avant de reprendre la croissance de gan ou aln a haute temperature (680 a 750c). Nous avons en particulier etudie les proprietes d'une couche de gan en fonction de la temperature a laquelle est realisee l'etape de nitruration. Lorsque les conditions de demarrage de la croissance sont optimisees, nous avons pu observer des oscillations de rheed pendant la croissance de la couche de gan. Nous avons etudie l'effet du rapport v/iii sur la morphologie de surface et les proprietes optiques et structurales de cette couche. Nous avons propose l'utilisation de l'indium en tant que surfactant pour ameliorer ces proprietes. Nous avons ensuite aborde la realisation de superreseaux gan/aln dont nous avons optimise les interfaces. Les mecanismes de relaxation des contraintes de aln sur gan et gan sur aln ont ete etudies. Nous avons egalement elabore les alliages algan et ingan, comme barrieres quantiques dans les heterostructures. Nous avons montre que la relaxation elastique des contraintes de gan en epitaxie sur aln donne lieu a la formation d'ilots de tailles nanometriques, qui se comportent comme des boites quantiques. Leur densite et leur taille dependent de la temperature de croissance, et des conditions de murissement apres croissance. Les proprietes optiques de ces ilots sont gouvernees a la fois par les effets de confinement quantique et par le fort champ piezo-electrique induit par la contrainte dans les ilots.
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Mohammad, Rezek Mahmoud Salim. "The Electronic Band Structure Of Iii (in, Al, Ga)-v (n, As, Sb) Compounds And Ternary Alloys." Phd thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606292/index.pdf.
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In this work, the electronic band structure of III (In, Al, Ga) - V (N, As, Sb)
compounds and their ternary alloys have been investigated by density functional
theory (DFT) within generalized gradient approximation (GGA) and empirical
tight binding (ETB) calculations, respectively.
The present DFT-GGA calculations have shown direct band gap structures
in zinc-blende phase for InN, InAs, InSb, GaN, and GaAs. However, indirect
band gap structures have been obtained for cubic AlN, AlSb and AlAs com-
poundshere, the conduction band minima of both AlN and AlAs are located at X symmetry point, while that of AlSb is at a position lying along Gamma- X direction. An important part of this work consists of ETB calculations which have been parameterized for sp3d2 basis and nearest neighbor interactions to study the band gap bowing of III(In
Al)- V(N
As
Sb) ternary alloys. This ETB model provides a satisfactory electronic properties of alloys within reasonable calculation time compared to the calculations of DFT. Since the present ETB energy parameters reproduce successfully the band structures of the compounds at ¡
and X symme- try points, they are considered reliable for the band gap bowing calculations of the ternary alloys. In the present work, the band gap engineering of InNxAs1¡
x, InNxSb1¡
x, InAsxSb1¡
x, Al1¡
xInxN, Al1¡
xInxSb and Al1¡
xInxAs alloys has been studied for total range of constituents (0 <
x <
1). The downward band gap bowing seems the largest in InNxAs1¡
x alloys among the alloys considered in this work. A metallic character of InNxAs1¡
x, InNxSb1¡
x and InAsxSb1¡
x has been ob- tained in the present calculations for certain concentration range of constituents (N
As) as predicted in the literature. Even for a small amount of contents (x), a decrease of the electronic e®
ective mass around ¡
symmetry point appears for InNxAs1-x, InNxSb1-x and InAsxSb1-x alloys manifesting itself by an increase of the band curvature. The calculated cross over from indirect to direct band gap of ternary Al alloys has been found to be consistent with the measurements. As a last summary, the determinations of the band gaps of alloys as a function of contents, the concentration range of con- stituents leading to metallic character of the alloys, the change of the electronic effective mass around the Brillioun zone center (Gamma) as a function of alloy contents, the cross over from indirect to direct band gap of the alloys which are direct on one end, indirect on the other end, are main achievements in this work, indispensable for the development of mate- rials leading to new modern circuit components.
19
Rossner, Ulrike. "Epitaxie des nitrures de gallium et d'aluminium sur silicium par jets moléculaires : caractérisation structurale et optique." Université Joseph Fourier (Grenoble), 1995. http://www.theses.fr/1995GRE10181.
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Les nitrures de gallium et d'aluminium ont ete elabores par epitaxie par jets moleculaires (mbe) sur des substrats de silicium. La phase cubique de ces nitrures a ete obtenue sur le si(001). Elle est initiee par une carburation de la surface du silicium precedante a la croissance des nitrures: cette carburation permet de recouvrir completement la surface des substrats par des cristallites de sic cubique. La phase hexagonale du gan et de l'ain a ete observee sur le si(111). Pour la croissance du gan hexagonal, des couches tampons d'ain ont ete utilisees. Le nitrure d'aluminium a ete caracterise structuralement (par rheed, diffraction x et microscopie electronique). Pour le nitrure de gallium, semiconducteur a grand gap (3. 4 ev) qui constituait le but principal de notre travail, une etude structurale detaillee ainsi qu'une etude optique (par photoluminescence et cathodoluminescence) ont ete realisees. L'azote reactif pour la croissance des nitrures a ete obtenu par deux methodes differentes: par la creation d'un plasma d'azote par resonance cyclotron-electronique (ecr-mbe) ou par la decomposition de l'ammoniac sur la surface de l'echantillon (gas-source-mbe). Pour travailler en ecr-mbe, une source de plasma a ete developpee et caracterisee: elle est concue telle que le rapport ions/atomes neutres d'azote soit faible pour minimiser l'endommagement eventuel des nitrures par des ions energetiques
20
Lee, Chan-Shang, and 李慶雄. "Investigation of microstructure and mechanical property of Al/AlN composite." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/95671974583660049875.
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Yang, Tsung-yeh, and 楊宗燁. "PROCESSING OF Al/SiC-AlN ALLOY COMPOSITE FOR HEAT SINK APPLICATION." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/86803526744535924474.
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碩士大同大學
材料工程學系(所)
101
High content of silicon carbide-reinforced aluminum composite was widely used because its high thermal conductivity, low coefficient of thermal expansion. However, current performance of Al/SiC substrate will not be enough to meet the thermal management requirement in the future. Further improvements on the thermal conductivity of Al/SiC composites is a must. Adding AlN into SiC to fabricate Al/SiC-AlN appears to be a potential way to improve thermal conductivity of the composites. In the first part of this study, Al/SiC was fabricated using various particle sizes and different purities of silicon carbide by squeeze casting method. The influences of processing parameters such as temperature, particle size, casting pressure were also investigated. In the second part of study, -150+325 mesh silicon carbide was blended with 20μm aluminum nitride with different weight fraction and were used to fabricate Al/SiC-AlN composites. In order to investigate the effects of surface condition of AlN on the thermal properties, silicon alkoxide-coated aluminum nitride was used in third part of the study. The results showed that the best squeeze casting conditions were：temperature, 800℃; pressure, 50MPa; holding time, 10 minutes. The powder particle size range should be narrow. With this condition, the best relative density of composites of Al/SiC-AlN could reach 97%. The microstructure and XRD analyses showed SiC and AlN distributed uniformly and there was no Al4C3 phase detected. In the Al/SiC specimen, the Al/LgSiC had the highest thermal conductivity which could reach 189 W/mK but the flexural strength was only 225 MPa; In contrast, Al/FbSiC had the lowest thermal conductivity of 129 W/mK but the highest flexural strength was up to 343 MPa. Due to the poor wettability and high thermal resistant between Al alloy and AlN, the thermal conductivity of Al/gSiC-AlN decreased with the AlN content. On the contrary, as the amount of surface coated AlN increased in Al/gSiC-sAlN, the thermal conductivity increased to a highest value of 208W/mK. The flexural strength of Al/gSiC-AlN and Al/gSiC-sAlN increase as the content of aluminum nitride increase. But Al/gSiC-sAlN had higher flexural strength than Al/gSiC-AlN. The highest flexural strength reached 303MPa.
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Chen, Chia-Wei, and 陳佳緯. "Fabrication of AlN Films Deposited on Al Substrate by Microwave Plasma." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/97673611134893326479.
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碩士龍華科技大學
工程技術研究所
101
In this study, the microwave plasma nitriding method will be carried out for the aluminum nitride surface treatment way to explore the formation and research. Research methods to change process parameters include base temperature, reaction gas ratio,microwave power to microwave plasma nitriding treatment. Analysis results base temperature 550℃, reaction gas ratio N2:H2=50:150sccm, microwave power 1000W to better nitridation reaction Finally, In this study, the best parameters are: microwave power 1000W, Reaction gas N2:H2=50:150sccm and base temperature 550℃to microwave plasma nitriding treatment, nitrided aluminum plate specimen analysis,the results showed that nitrogen ratio can be as high as 23.38% and a thickness of 15μm.
23
Yao, Li-Ren, and 姚力仁. "Low-vacuum preparation of Al and AlN thin films by magnetron sputtering." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/80713755696017924667.
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Chang, Wei-kai, and 張為凱. "Applying PIII process to study the Growth Mechanism of AlN / Al Alloys." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/32806901530820154554.
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碩士國立臺灣科技大學
機械工程系
101
The objective of this study is to investigate the growth mechanism of AlN on Aluminum alloys by applying Nitrogen Plasma Immersion Ion Implantation (N-PIII) technique to treat the surface layer of the aluminum alloy. AA7005、commercially pure aluminum (1N30) and super high purity aluminum(5N) are used as the substrate material in this study. Effects of bias voltage 10 kV, 20kV and 30kV of N-PIII process on the thickness, growth rate and microstructure of the modified layer was studied. The influences post-process heat-treatment on the microstructure and the surface characteristics of the modified layer were investigated and analyzed. Nano-indentation test and Glow Discharge Spectrometer (GDS) test were conducted on the treated specimens to obtain the depth evolution profiles of the hardness and the depth profiles of nitrogen element from the surface of specimen, respectively. The friction coefficients of the modified layer were measured by Flat-on-Flat method. Specimens being N-PIII treated were subjected to heat treatments. Then, nano-indentation test, GDS test, Flat-on-Flat test were conducted on these heat-treated specimens to examine the effects of post-process heat treatment on the surface properties of the modified layer. Experimental results showed that the penetration depth of nitrogen ion is related to the bias voltage and the impurity contents of aluminum alloy. The higher bias voltage, the deeper penetration depth and the larger nitrogen ions dosage. High bias voltage can significantly increase the surface hardness of treated specimens; the effect is highly profound in 5N specimens. After the heat-treatment, internal nitrogen in the specimen would diffuse to the external, and reduce the width of modified layer. This phenomenon can promote the formation of aluminum nitride, and to get better surface property. The microstructure observation showed that, after heat treatment bubbles were generated in the white layer which is a compound layer of AlN, εnitrateγ'nitrate. The generate of bubbles will severely affect the flatness of the aluminum nitride layer, increasing the coefficient of friction of the specimen. Specimen subjected to PIII treatment plus laser surface heat treatment, failed to improve the surface hardness, and the value of surface hardness reduced to the hardness values of unmodified specimen.
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Chang, S. T., and 張韶廷. "A Study of the Mechanical Properties on Squeeze Casting AlN/Al Composites Materials." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/22323163057277296616.
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碩士國立成功大學
材料科學及工程學系
87
Aluminum Nitride (AlN) has been used for substrate application because its extremely high conductivity, good electrical resistance and low thermal expansion coefficient. This ceramic is also know as good millitary armor material for reasons that is still under investigation. One drawback with this material for structural application is its low fracture toughness. Aluminum metal is therefore added into AlN in this study for the purpose of improving toughness. This study is on mechanical properties of AlN/Al composites. The experimental process is described as follows. First, sintering porous AlN preform in N2、1500℃、1 hour, then by squeeze casting process, molten pure Al was infiltrated into AlN preform to make AlN/Al composite. The produce materials were subjected to examination, microstructure, physical and mechanical properties.
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Chang, Cheng-Chieh, and 張政傑. "Study on the Effect of AlN/Al Diffusion Bonding with Rare Earth Element." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/23xzcv.
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碩士國立臺北科技大學
製造科技研究所
106
In this study, the effect of adding different content of La of titanium film on AlN substrate was examined. Then, substrate direct bonding with AlN/Al. Ceramic surface was pre-metallized by Physical Vapor Deposition (PVD). The effect of different content on substrate were examined by heat treatment (350℃-550℃) and XRD measurement. Solid-state diffusion bonding carried out through vacuum hot press at the temperature of 350℃, 450℃ and 550℃ for 2 hours. Bonding mechanism, tensile bonding effect, thermal resistance properties and mechanical properties were inspected. The XRD results show that the TiN phase generate after heat treatment at 550 °C. This proves that the rare earth element La can increase the wettability and enhance the reaction with AlN, resulting in a relatively stable TiN phase. Observing cross section of the sample through EPMA, atomic diffusion distance will be increased by adding more content of La. Adding the content of 2 wt% La, increasing the diffusion distance by 67%.Moreover, the results from TEM indicated that the primary interfacial reaction layers were composed of AlN/TiN/Al3Ti/CuTi/Al4Cu9,Al2Cu,AlCu/Al. Through the thermal resistance detection and analysis, it is reveal that the thermal resistance value is 0.54℃/W at 450℃, and the thermal resistance value becomes higher due to the thickening of the reaction layer at 550℃. The thermal resistance value is 0.72℃ /W. The tensile strength at a temperature of 350 ° C is 6.14 ~ 8.51 MPa, and tensile strength is greatly increased over 28 MPa of 450 ° C.
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Huang, Kuo-Hsiung, and 黃國雄. "Production of Ultrafine Al Powders and its Application on the Sintering of AlN Substrates." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/73528197765693413689.
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Ching-HsinLin and 林靜欣. "Process Development for Combustion Synthesis of AlN Powder Using Al Reactant with Different Morphology." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/63075999281471129810.
Full textAbstract:
碩士國立成功大學
化學工程學系碩博士班
98
Process development for combustion synthesis of AlN powder using Al reactant with different morphology. The reactant of experiment is different from the aluminium powder used in laboratory, the raw materials used are A-2 and A-3. A-2: The raw materials used are the 75 μm flaky aluminium powder, using programmble temperature and humidity chamber to take the surface treatment of aluminium powder. A combustion synthesis reaction was ignited by heating and lead air to fire, produce AlN under the appropriate reaction condition, the conversion ratio of product is in above 99. A-3: 15 ~ 85 μm gray irregular particle form aluminium powder, added with aluminium nitrogen process a combustion synthesis reaction, then produce AlN. The conversion ratio of product is 97.97. It is APS, GPS and phosphoric acid to take the nitrogen aluminium powder surface treatment used in the laboratory, analyze its ESCA picture, and then analyze ESCA picture of the commercial aluminium nitrogen powder.
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Nagendra, N. "Processing, Microstructure And Fracture Characteristics Of High Volume Fraction Al2O3/(Al-AlN)Matrix Composites." Thesis, 1997. http://etd.iisc.ernet.in/handle/2005/1796.
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Lin, Chen-feng, and 林辰峰. "The study of estimate life of LED modules on the AlN, Al2O3 and Al substrates." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/436e84.
Full textAbstract:
碩士國立中央大學
光電科學與工程學系
102
This study is to establish the aluminum nitride substrate, the alumina substrate and the aluminum substrate LED module to estimate its lumen maintenance of life model. Refer to IES LM-80-08 lumen maintenance light measurement methods. The aluminum nitride substrates, alumina substrates, aluminum substrates, each type for 10 pcs, placed under 55 and 85 degrees environment. Using the IES LM-79-08 light emitting diodes electrical and photometric characteristics measuring method, every 1000 hours recording lumen maintenance until 6000 hours. The resulting data use IES TM-21-11 estimate diode light source LED lumen maintenance performed life prediction module. LED modules to build three different models to estimate the life of the substrate, and the results can be applied in future in situ temperature measurement test (ISTMT) combined interpolation method to estimate the overall life of the lighting system. The result of curve fitting L70(6K)：At 55 °C, AlN substrate is 36,642 hours, Al2O3 substrate is 27116 h, Al substrate is 26932 h, At 85 °C, Al2O3 substrate is 5422 h, AlN substrate is 5379 h, Al substrate is 5035 h. Data interpolating the temperature 70 ° C results, AlN substrate is 13724 h, Al2O3 substrate is 11886 h, Al substrate is 11401 h.
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Jaw, Jyh-Hong, and 趙志鴻. "Growth Mechanisms and Wear Behavior of AlN Crystals in Fe-Mn-Al-C Alloys after Nitridation." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/46707170788982266308.
Full textAbstract:
博士國立臺灣科技大學
機械工程系
92
The nitriding kinetics and the interface microstructure of the high toughness austenitic Fe-Mn-Al-C-(Cr) alloys were studied at 900, 1000, and 1050°C in a flowing atmosphere of pure nitrogen for 1, 9, 16, and 25 hr. The wear behavior of the alloys with/without nitridation as also examined. The plate-shaped h.c.p. AlN is the major product of the chemical reaction in the nitriding process of the alloys. The growth kinetics of the nitride layer obeys the parabolic law. On the one hand, the N atoms diffuse into the alloy matrix by volume diffusion. AlN is a stoichiometric ionic-compound which can prevent the diffusion of N atoms. Because the area fraction of AlN increased with increasing Al content, the area for N atoms diffusion decreased. Thus, the more the Al content in alloys, the less the depth of the nitride layer. On the other hand, the N atoms diffuse to the front of the AlN crystals at the reaction front quickly along in the phase interface between the AlN crystal and the matrix. Then AlN formed via the chemical reaction between N and Al. The more the Al content in alloys, the more the number of the trapped N atoms, and the less the diffusion depth of the N atoms. Therefore, it is pointed out that the depth of the nitride layer decreased with increasing Al content again. The orientation relationship between the AlN and f.c.c. matrix is (0001)AlN // (1-11)matrix, (2-1-10)AlN // (110)matrix, and [01-10]AlN // [-112]matrix. The ledge mechanism controls the growth behavior of the AlN in the alloy matrix. The terrace planes of the ledge structure are (0001)AlN // {111}matrix, and the ledge planes are {01-10}AlN // {-112}matrix. There are four different {111} planes in the f.c.c. crystal structure, and just only one (0001) plane in the h.c.p. AlN. The result in the AlN precipitated in the form of Widmanstätten-plate structure. The hardness of the raw alloys of the Fe-Mn-Al-C systems increased with increasing Al content. When oxide film was absent on the worn surface, the wear resistance increased with increasing hardness of the raw alloy. However, when oxide was absent on the worn surface, the governing wear mechanisms were abrasion, surface fatigue, shear fracture, or delamination, which cause severe wear. On the contrary, when oxide formed on the worn surface due to the alloys have been nitridized or the Al content was smaller in alloys, the governing wear mechanism was tribooxidation, which causes less wear.
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Ive, Tommy [Verfasser]. "Growth and investigation of AlN/GaN and (Al,In)N/GaN based Bragg reflectors / von Tommy Ive." 2005. http://d-nb.info/978915607/34.
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Chiang, Li-Wei, and 姜禮維. "Effect of the AuSn Eutectic Bonding Joint by Studying the Underneath Al/AlN Multiple Strain Release Layers." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/3u5xs3.
Full textAbstract:
碩士國立虎尾科技大學
光電與材料科技研究所
101
In this thesis, the Al/AlN multiple-layer films were used as the strain release layers between glass substrate and AuSn eutectic metal. Due to a great amount of heterostructural interface change, it is beneficial to increase the material toughness, stop the fissure expansion, and enhance the abrasion resistance. In addition, Al is a soft metal with extraordinary ductility, and AlN, as a ceramic material, shows extremely high heat transfer coefficient and hardness. The integration of these two materials can form a structure that is applicable to create the strain release layers so as to enhance the later deposited film reliability. This study utilized sputtering to deposit one set, two sets, and three sets of Al/AlN multiple-layer films onto the glass substrates, and finalize an Al cap layer. After the aluminum film surfaces were chemically processed. The electroplating technique was used to prepare the required AuSn eutectic bonding layers. The optimized shear stress and bonding temperature were discussed for various release layers. It was found that the optimal bonding temperature and shear stress increased with increasing the number of film layers. Subsequently, the SEM and XRD analysis were performed on various films to find more the optimal eutectic phase ζ (Au5Sn). In the final, the photolithography was used to define the pattern of flip-chip LED bounding carrier. The encapsulated LED sample was operated at 20 mA, and the forward voltage was measured as 4.09 V.
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Rudolph, Pascale [Verfasser]. "Physikalische Chemie der Laser-Material-Wechselwirkung mit Ba-Al-Borosilikatglas, AlN, SiC, SiC-TiC-TiB2 / von Pascale Rudolph." 2001. http://d-nb.info/964150204/34.
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Lumbantoruan, Franky Juanda, and 盧釩達. "The Growth of Ultrathin Al(Ga,In)N/AlN/GaN Heterostructures by MOCVD for High Electron Mobility Transistor Applications." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/aq76sm.
Full textAbstract:
博士國立交通大學
材料科學與工程學系所
107
Due to the characteristic of wide bandgap, high breakdown field, high electron mobility and excellent thermal conductivity, GaN has turned into one of candidates to exceed the limit of silicon to pursue the groundbreaking high-frequency, high-efficiency, and high power density conversion. GaN high electron mobility transistors (HEMT) have already attracted a lot of attentions due to the generation 2 Dimensional Electron Gas at the interface. Compared to AlGaN as the barrier layer, the use of InAlN and InAlGaN as barrier layer is attractive due to the higher free carrier at the interface attributed to the strong polarization of barrier layer. The objective of this thesis is to investigate, understand and control the mechanism that limits the performance of AlGaN/GaN and InAlGaN/GaN transistors. Particular attention will be given to the optimization growth condition for both AlGaN barrier layer and InAlGaN barrier layer and the gate leakage analysis for InAlGaN HEMT. In the first part, we report the influence of TMAl preflow to the AlN buffer layer and GaN thin film was studied by Optical Microscope, Atomic Force Microscope, X-ray diffraction and Transmission Electron Microscope. Different duration of TMAl preflow lead to substantially differences of the AlN buffer layer and GaN film properties in terms of surface morphology and crystal quality. With the optimum duration of TMAl preflow, crystal quality and surface roughness of GaN can be improved In the second part we describe the effect of NH3 flow rate during the AlGaN barrier layer growth on the material properties of AlGaN/GaN HEMT. NH3 flow rate during AlGaN barrier growth not only affects the growth efficiency and surface morphology of the AlGaN barrier layer but also the influences the concentration of carbon impurity in the AlGaN barrier layer. Carbon, origination from the metal precursor, plays a role in the electron compensation for AlGaN/GaN HEMT. Optimized NH3 flow results in the improvement of surface morphology and recovered free carrier 2 Dimensional Electron Gas. In the third part, the gate leakage mechanism for InAlGaN/GaN high electron mobility transistors is systematically studied using temperature-dependent gate current- voltage characteristics. The gate current of the InAlGaN/GaN HEMT was analyzed by fitting the experimental data using Themionic Emission (TE), Poole Frenkel (PF) and Fowler-Nordheim (FN) tunneling. The results show that (1) reverse leakage current in the thin InAlGaN barrier layer is dominated by FN tunneling due to triangular barrier formation; (2) for thicker barrier layer, the reverse leakage current at low electric field (<2.23MV/cm) is dominated by PF emission; (3) at high electric field near the threshold voltage the FN tunneling dominates. Finally, the effects of the growth temperature on the structural and electrical properties of the InAlGaN/GaN heterostructures grown on c-plane sapphire substrates are investigated. It is observed that the Gallium incorporation increases with the increase of the growth temperature. Meanwhile, the surface roughness decreases from 0.49 nm to 0.34 nm with the increase of growth temperature. The variation of structural properties, composition and surface morphology influences the transport properties of the InAlGaN/GaN heterostructures. The experiement shows that optimized temperature window is between 900°C and 950°C.
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Tsai, Bing-Fu, and 蔡秉富. "The Effect of AlN Layer on the Electrical Properties of Ni-Cr-Si-Al Thin Film by DC Magnetron Sputtering." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/89392747959657533480.
Full textAbstract:
碩士國立高雄應用科技大學
機械與精密工程研究所
101
In this study, aluminum nitride and nickel-chromium-silicon- aluminum thin films are prepared using DC magnetron sputtering deposition, respectively. To obtain different compositions of AlN thin film, the sputtering conditions are adjusted such as sputtering power, concentration of nitrogen ratio and annealing temperature. The effects of sputtering parameters on the phase transformation, microstructure and mechanical property, and electrical property of AlN and Ni-Cr-Si-Al thin films are investigated. The results show that as-deposited films with amorphous structure are observed using X-ray diffraction analysis. When 500 W sputtering power is applied to prepare AlN thin films, the AlN peaks are appeared at 500 ℃ annealing. The AlN crystalline is enhanced in thin films at 600 ℃ annealing. In addition, pure AlN phase with hexagonal can be obtained at 500 ℃ annealing when the sputtering power is enhanced from 500 W to 800 W. In mechanical analysis, the micro-hardness is increased from 32 Hv (500 W) to 70 Hv (800 W), and the scratch width is decrease from 90 μm (500 W) to 15μm (800 W). Based on the optimum processes of AlN thin films, the Ni-Cr-Si-Al thin films are deposited on AlN thin film/Al2O3 substrates. The effects of Ar/N2 ratio, sputtering power and annealing temperature of AlN thin film on the electrical properties of Ni-Cr-Si-Al thin films are investigated. The results showed that the resistivity of Ni-Cr-Si-Al thin films with AlN film as middle layer is 9962 μΩ-cm with -205 ppm/℃TCR after 360 ℃/4 h annealing. However, the resistivity of Ni-Cr-Si-Al thin films without AlN film as middle layer is 10789 μΩ-cm with -180 ppm/℃TCR after 360 ℃/4 h annealing.