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Manufacturing of aircraft parts is often complex and time-consuming, which has led to an increased interest in new manufacturing technologies in the Swedish industry such as additive manufacturing (AM). Additive manufacturing techniques could be a solution to meet the aircrafts’ demand since it contributes to an efficient manufacturing and allows a just-in-time production of complex metal parts in their final shape. However, the use of AM aluminum for aircraft applications is in a development phase and no surface treatment process exists. Thereby, it is of high interest to further investigate surface treatments for AM alloys. Currently at Saab AB, conventional aluminum alloys are generally anodized in tartaric sulphuric acid (TSA) to improve the corrosion resistance and adhesion properties of the metal. On the behalf of Saab AB, there is also an interest in establishing powder coating as a surface treatment. This master thesis’ purpose is to investigate the anodizing and adhesion properties for the two additive manufacturing alloys - AlSi10Mg and ScalmalloyⓇ, and compare it with the conventionally produced Al alloy 2024-T3. The anodization and the powder coating is examined by using following characterization techniques: profilometry, light microscopy, scanning electron microscopy and contact angle measurements. The results from the experimental part indicated successful anodizations for all the alloys and good adhesion properties for powder coating. This research is a first step in contributing to a better understanding of the anodic coating and adhesion properties for the AM samples ScalmalloyⓇ and AlSi10Mg

The aim of this diploma thesis is to analyse the porosity of die - cast cast that were made of the alloy AISi9u3 in iron-foundry Skoda Car Mlada Boleslav. The analysis and the sample comparisons are based on my own measurements and are also connected with previous diploma thesis which deals with that issue and was drawn up at Technical University in Brno. All measurements were statistically tested.

Among the commercial aluminum alloys, aluminum 319 (Al-7wt%Si-4wt%Cu) type alloys are popularly used in automobile engine parts. These alloys have good casting characteristics and excellent mechanical properties resulting from a suitable heat treatment. To get a high strength in the 319 type alloys, grain refining, reducing the porosity, solid solution hardening, and precipitation hardening are preferred. All experimental variables such as solidification condition, composition, and heat treatment are influence on the precipitation behavior; however, precipitation hardening is the most significant because excess alloying elements from supersaturated solid solution form fine particles which act as obstacles to dislocation movement. The challenges of the 319 type alloys arise due to small size of precipitate and complex aging response caused by multi components. It is important to determine the chemical composition, crystal structure, and orientation relationship as well as precipitate morphology in order to understand the precipitation behavior and strengthening mechanism. In this study, the mechanical properties and microstructure were investigated using transmission electron microscopy and three dimensional atom probe tomography. The Mn and Mg effects on the microstructure and mechanical properties are discussed with crystallographic study on the iron intermetallic phases. The microstructural evolution and nucleation study on the precipitates in the low-Si 319 type aluminum alloys are also presented with sample preparation and analysis condition of TEM and 3DAP tomography.

The effects of pore density and distribution were investigated on the fatigue crack initiation behavior in an A713 sand cast aluminum alloy plate of 12 mm thickness. The applied stress- the number of cycles to failure (S-N) curves of the samples taken from 2 mm and 5 mm from the free surface were obtained using four-point bend fatigue testing at room temperature, frequency of 20 Hz, stress ratio of 0.1, sinusoidal waveform, and in ambient air. The fatigue strengths of both, the 2 mm and 5 mm samples were 60% of the yield strength (σy=171.9 MPa) of the alloy. Optical microscopy, SEM, and EDS mapping were used to characterize pores and particles in 2 mm and 5 mm samples. The average pore sizes of the 2 mm and 5 mm samples were measured to be 10 to 14 μm, and 14 to 32 μm, respectively. The pore number densities in 5 mm and 2 mm samples were comparable, but higher number densities of non-clustered coarse pores (gas pores) were observed in 5 mm samples. The crack population found after fatigue testing showed a Weibull function of stress level. The peaks of strength distributions of fatigue weak link density of 5 mm and 2 mm samples were measured to be 0.017 mm-2 at 67.6 % σy, and 0.01027 mm-2 at 69.5% σy. Crack populations, when normalized by number densities of gas pores (non-clustered) and number densities of shrinkage pores (clustered), giving crack nucleation rate (crack/pore, mm-2), showed a good fit with the Weibull function in 2 mm and 5 mm samples. Shrinkage and gas pores could both become the main crack initiation sites (i.e. fatigue weak links) in this alloy. Higher nucleation rates of gas pores and shrinkage pores were observed in 5 mm samples compared to those rates in 2 mm samples. At high applied stresses, the 2 mm samples showed better fatigue lives than those of 5 mm samples. Fractured surfaces were analyzed using SEM and found that the main crack initiation were predominately from pores. The pores on the fractured surfaces were counted and their depth and width were measured. It was found that the cracks may not necessarily initiate from coarse pores, but sometimes from shrinkage pores (i.e. group of pores). The depth from the free surface, the width, the size, and the orientation of pores are key factors in increasing the driving force for crack initiation and subsequently those pores turn into long cracks. Moreover, the aspect ratios of pores on the main cracks were measured and found that in 5 mm samples, some pores have an aspect ratios of less than 0.7, which means that these pores are elongated in depth and have a narrow width which increase the stress concentration on the surface, thus, increasing the driving force for crack nucleation.

Nous avons pour objectif de jeter les bases d’une technologie en totale rupture avec celles existantes pour la fabrication d’une nouvelle génération de composants électroniques à base du Carbure de Silicium pour les applications à très hautes températures (jusqu’à 600°C). Cette nouvelle technologie est basée sur l'emploi d'une nouvelle génération de matériaux pour les contacts ohmiques haute température. Nous avons ciblé la phase Ti3SiC2, qui est une phase céramique/métallique, pour former un bon contact ohmique stable et fiable à haute et très haute température. A savoir que l’aspect céramique est nécessaire pour assurer une bonne stabilité thermique à haute température, et l’aspect métallique est nécessaire pour obtenir des bonnes propriétés électriques (bonne conductivité électrique, faible résistance électrique…). Dans le but d’élaborer le Ti3SiC2 sur SiC, un film mince de 200 nm d’un alliage TixAl1-x a été déposé sur SiC-4H suivit d’un recuit sous Ar. Dans cette étude, on a fait varier la concentration du Ti et d’Al dans le dépôt métallique (Ti20Al80, Ti30Al70, Ti50Al50 et Ti), et on a aussi varié la température de recuit de 900°C à 1200°C. Des analyses structurales comme le DRX, MET, MEB et XPS ont été effectuées après recuit. Pour caractériser électriquement la couche Ti3SiC2 synthétisée sur SiC, des motifs TLM ont été réalisés. Des caractérisations électriques à température ambiante et à très haute température (jusqu’à 600°C) ont été mis en œuvre pour chaque type de dépôt et par conséquence la hauteur de barrière de potentielle a été également déterminée. Enfin, pour étudier la stabilité thermique du Ti3SiC2 sur SiC, des tests de vieillissement ont été réalisé à 600°C sous Ar. / The growth of Ti3SiC2thin films was studied onto 4H-SiC (0 0 0 1) 8◦and 4◦-off substrates by thermalannealing of TixAl1−x(0.5 ≤ x ≤ 1) layers. The annealing time was fixed at 10 min under Argon atmosphere.The synthesis conditions were also investigated according to the annealing temperature (900–1200◦C)after deposition. X-Ray Diffraction (XRD) and Transmission Electron Microscope (TEM) show that thelayer of Ti3SiC2is epitaxially grown on the 4H-SiC substrate. In addition the interface looks sharp andsmooth with evidence of interfacial ordering. Moreover, during the annealing procedure, the formationof unwanted aluminum oxide was detected by using X-Ray Photoelectron Spectroscopy (XPS); this layercan be removed by using a specific annealing procedure. Using TLM structures, the Specific Contact Resistance (SCR) at room temperature of all contacts was measured. The temperature dependence up to 600°C of the SCR of the best contacts was studied to understand the current mechanisms at the Ti3SiC2/SiC interface. Experimental results are in agreement with the thermionic field emission (TFE) theory. With this model, the barrier height of the contact varies between 0.71 to 0.85 eV.

Severe plastic deformation methods are of great interest in industrial forming applications, as they give rise to significant refinement in microstructures and improvements in mechanical and physical properties. In the &ldquo / Equal Channel Angular Extrusion (ECAE)&rdquo / , which is the most common method for production of ultrafine grained bulk samples, very high plastic strains are introduced into the bulk material without any change in cross section. This study is composed of two main parts. Part I focuses on the plastic deformation behavior of Al alloys by modeling ECAE with Msc. Marc finite element software. A series of numerical experiments were carried out for the die angles of 90&deg / , 120&deg / , and 150&deg / , different friction conditions, and different round corners. Besides, the effects of strain hardening characteristics of the material, strain hardening coefficient (K) and exponent (n) of Hollomon&rsquo / s law, on corner gap formation and strain homogeneity in equal channel angular pressing process were investigated quantitatively. The results were compared and verified with those of the upper bound analysis. The numerical results showed that the process performance can be improved by modifying the die corner curvature accordingly, without running time consuming simulations. On the other hand, the aim of Part 3 is to investigate the texture evolution, mechanical response and the corresponding mechanisms, in terms of the flow stress anisotropy and tension-compression asymmetry in the ZK60 Mg alloy. The alloy was processed using ECAE, with different processing routes and temperatures, in order to produce samples with a wider variety of microstructures and crystallographic textures. Several mechanical tests and microstructure examinations were carried out / and the flow stress anisotropy and tension-compression asymmetry of the as-received and processed samples were measured. It was found that the initial texture has a strong effect on the resulting textures / and the textures, combined with the microstructure effect, define the mechanical properties of processed samples. Thus, the tension-compression asymmetry and the flow stress anisotropy variations in the processed samples are attributed to the generated textures and it is possible to control these properties by controlling the processing route and temperature.

Fundamental understanding of atmospheric corrosion mechanisms requires an in-depth understanding on the dynamic interaction between corrosive constituents and metal/alloy surfaces. This doctoral study comprises field and laboratory investigations that assess atmospheric corrosion and metal release processes for two different groups of alloys exposed in chloride-rich environments. These groups comprise two commercial Zn-Al alloy coatings on steel, Galfan™ (Zn5Al) and Galvalume™ (Zn55Al), and four copper-based alloys (Cu4Sn, Cu15Zn, Cu40Zn and Cu5Zn5Al). In-depth laboratory investigations were conducted to assess the role of chloride deposition and alloy microstructure on the initial corrosion mechanisms and subsequent corrosion product formation. Comparisons were made with long-term field exposures at unsheltered marine conditions in Brest, France. A multitude of surface sensitive and non-destructive analytical methods were adopted for detailed in-situ and ex-situ analysis to assess corrosion product evolution scenarios for the Zn-Al and the Cu-based alloys. Scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS) were employed for morphological investigations and scanning Kelvin probe force microscopy (SKPFM) for nobility distribution measurements and to gain microstructural information. SEM/EDS, infrared reflection-absorption spectroscopy (IRAS), confocal Raman micro-spectroscopy (CRM) and grazing incidence x-ray diffraction (GIXRD) were utilized to gain information on corrosion product formation and possibly their lateral distribution upon field and laboratory exposures. The multi-analytical approach enabled the exploration of the interplay between the microstructure and corrosion initiation and corrosion product evolution. A clear influence of the microstructure on the initial corrosion product formation was preferentially observed in the zinc-rich phase for both the Zn-Al and the Cu-Zn alloys, processes being triggered by microgalvanic effects. Similar corrosion products were identified upon laboratory exposures with chlorides for both the Zn-Al and the Cu-based alloys as observed after short and long term marine exposures at field conditions. For the Zn-Al alloys the sequence includes the initial formation of ZnO, ZnAl2O4 and/or Al2O3 and subsequent formation of Zn6Al2(OH)16CO3·4H2O, and Zn2Al(OH)6Cl·2H2O and/or Zn5(OH)8Cl2·H2O. The patina of Cu sheet consists of two main layers with Cu2O predominating in the inner layer and Cu2(OH)3Cl in the outer layer, and with a discontinuous presence of CuCl in-between. Additional patina constituents of the Cu-based alloys include SnO2, Zn5(OH)6(CO3)2, Zn6Al2(OH)16CO3·4H2O and Al2O3. General scenarios for the evolution of corrosion products are proposed as well as a corrosion product flaking mechanism for some of the Cu-based alloys upon exposure in chloride-rich atmospheres. The tendency for corrosion product flaking was considerably more pronounced on Cu sheet and Cu4Sn compared with Cu15Zn and Cu5Al5Zn. This difference is explained by the initial formation of zinc- and zinc-aluminum hydroxycarbonates Zn5(OH)6(CO3)2 and Zn6Al2(OH)16CO3·4H2O on Cu15Zn and Cu5Al5Zn, corrosion products that delay the formation of CuCl, a precursor of Cu2(OH)3Cl. As a result, the observed volume expansion during transformation of CuCl to Cu2(OH)3Cl, and the concomitant flaking process of corrosion products, was less severe on Cu15Zn and Cu5Al5Zn compared with Cu and Cu4Sn in chloride-rich environments. The results confirm the barrier effect of poorly soluble zinc and zinc-aluminum hydroxycarbonates Zn5(OH)6(CO3)2 and Zn6Al2(OH)16CO3·4H2O, which results in a reduced interaction between chlorides and surfaces of Cu-based alloys, and thereby reduced formation rates of easily flaked off corrosion products. From this process also follows reduced metal release rates from the Zn-Al alloys. / Bättre molekylär förståelse för metallers atmosfäriska korrosion kräver en fördjupad kunskap i det dynamiska samspelet mellan atmosfärens korrosiva beståndsdelar och metallytan. Denna doktorsavhandling omfattar laboratorie- och fältundersökningar av korrosions- och metallfrigöringsprocesser av två grupper av legeringar som exponerats i kloridrika atmosfärsmiljöer: två kommersiella Zn-Al beläggningar på stål, Galfan™ (Zn med 5% Al, förkortat Zn5Al) och Galvalume™ (Zn55Al), samt fyra kopparbaserade legeringar (Cu4Sn, Cu15Zn, Cu40Zn och Cu5Zn5Al). Undersökningar har genomförts i renodlade laboratorie-miljöer med för-deponerade NaCl-partiklar i en atmosfär av varierande relativ fuktighet. Syftet har varit att utvärdera betydelsen av kloriders deposition och legeringarnas mikrostruktur på korrosionsmekanismen samt bildandet av korrosionsprodukter. Jämförelser av korrosionsmekanismer har även gjorts efter flerårsexponeringar av samma legeringar i en marin fältmiljö i Brest, Frankrike. Undersökningarna har baserats på ett brett spektrum av analysmetoder för detaljerade studier dels under pågående atmosfärisk korrosion (in-situ), och dels efter avslutad korrosion (ex-situ). Legeringarnas mikrostruktur och tillhörande variation i ädelhet hos olika faser har undersökts med svepelektronmikroskopi och energidispersiv röntgenmikroanalys (SEM/EDS) samt med en variant av atomkraftsmikroskopi (engelska: scanning Kelvin probe force microscopy, SKPFM). Korrosionsprodukternas tillväxt har analyserats in-situ med infraröd reflektions-absorptionsspektroskopi (IRAS), samt morfologi och sammansättning av bildade korrosionsprodukter ex-situ med SEM/EDS, konfokal Raman mikro-spektroskopi (CRM) samt röntgendiffraktion vid strykande ifall (GIXRD). Det multi-analytiska tillvägagångssättet har medfört att det komplexa samspelet mellan de skilda legeringarnas mikrostruktur, korrosionsinitiering och bildandet av korrosionsprodukter kunnat studeras i detalj. En tydlig påverkan av mikrostruktur på det initiala korrosionsförloppet har kunnat påvisas. Korrosionsinitieringen sker företrädesvis i mer zinkrika faser för såväl Zn-Al- som Cu-Zn-legeringar och orsakas av mikro-galvaniska effekter mellan de mer zinkrika, mindre ädla, faserna och omgivande faser. Deponerade NaCl-partiklar påskyndar den lokala korrosionen oberoende av mikrostruktur. Snarlika sekvenser av korrosionsprodukter har kunnat påvisas såväl efter laboratorie- som fältexponeringar. För Zn-Al-legeringar bildas först ZnO, ZnAl2O4 och/eller Al2O3, därefter Zn6Al2(OH)16CO3·4H2O och Zn2Al(OH)6Cl·2H2O och/eller Zn5(OH)8Cl2·H2O. På ren koppar bildas ett inre skikt dominerat av Cu2O, ett mellanskikt av CuCl och ett yttre skikt med i huvudsak Cu2(OH)3Cl. Beroende på legeringstillsats har även SnO2 och Zn5(OH)6(CO3)2 kunnat identifieras. En mekanism för flagning av korrosionsprodukter på kopparbaserade legeringar i kloridrika atmosfärer har utvecklats. Tendensen för flagning har visat sig vara mycket mer uttalad på ren Cu och Cu4Sn än på Cu15Zn och Cu5Al5Zn. Skillnaden kan förklaras med hjälp av det tidiga bildandet av Zn5(OH)6(CO3)2 och Zn6Al2(OH)16CO3·4H2O på Cu15Zn och Cu5Al5Zn som fördröjer bildandet av CuCl, en föregångare till Cu2(OH)3Cl. Därigenom hämmas även den observerade volymexpansionen som sker när CuCl omvandlas till Cu2(OH)3Cl, en process som visar sig vara den egentliga orsaken till att korrosionsprodukterna flagar. Resultaten bekräftar barriäreffekten hos de mer svårlösliga faserna Zn5(OH)6(CO3)2 och Zn6Al2(OH)16CO3·4H2O, vilken dels resulterar i en minskad växelverkan mellan klorider och de legeringsytor där dessa faser kan bildas, och dels i en reducerad metallfrigöringshastighet. / <p>QC 20140915</p> / Autocorr, RFSR-CT-2009-00015 Corrosion of heterogeneous metal-metal assemblies in the automotive industry / Atmospheric corrosion and environmental metal dispersion from outdoor construction materials

Recently, efforts have been made for self-powering the batteries and portable electronic devices by piezoelectric nanogenerators. The piezoelectric nanogenerators can work as a power source for nano-systems and also as an active sensor. The piezoelectric nanogenerator is a device that converts random mechanical energy into electrical energy by utilizing the semiconducting and piezoelectric properties. Also, the mechanical energy is always available in and around us for powering these nano devices. The aim of the present thesis work is to explore 1D and 2D ZnO nanostructures (nanorods and nanosheets) on metal alloy substrates for the development of piezoelectric nanogenerators in energy harvesting and sensors applications. Hydrothermal synthesis method was adopted for the growth of ZnO nanostructures. The nanogenerators were fabricated by using the optimized synthesis parameters and subsequently studied their performance for power generation and as an active speed sensor. These 1D and 2D nanostructures based nanogenerators have opened up a new window for the energy harvesting applications and sensors development. The thesis is divided into following six chapters. Chapter 1: This chapter gives a general introduction about energy harvesting devices such as nanogenerators, available energy sources, mechanical energy harvesting, ZnO material and the details on hydrothermal synthesis process. A brief literature survey on different applications of piezoelectric nanogenerators is also included. Chapter 2: A novel flexible metal alloy (Phynox) and its properties along with its applications are discussed in this chapter. Details on the synthesis of 1D ZnO nanorods on Phynox alloy substrate by hydrothermal method are presented. Further, the optimization of parameters such as growth temperature, seed layer annealing and substrate temperature effects on the synthesis of ZnO nanorods are discussed in detail. As-synthesized ZnO nanorods have been characterized using XRD, FE-SEM, TEM and XPS. Chapter 3: It reports on the fabrication of piezoelectric nanogenerator on Phynox alloy substrate as power generating device by harvesting the mechanical energy. Initially, the performance of the nanogenerator for power generation due to finger tip impacts was studied and subsequently its switching polarity test was also carried out. Output voltage measurements were carried out using the in-house developed experimental setup. Stability test was also carried out to see the robustness of the nanogenerator. Finally, the output voltage response of the nanogenerator was studied for its use as an active speed sensor. Chapter 4: Synthesis of Al doped 2D ZnO nanorsheets on Aluminum alloy (AA-6061) substrate by hydrothermal method is reported in this chapter. The optimized parameters such as growth temperature and growth time effects on the synthesis of ZnO nanosheets are discussed. As-synthesized ZnO nanosheets were characterized using XRD, FE-SEM, TEM and XPS. The Al doping in ZnO is confirmed by EDXS and XPS analysis. Chapter 5: Cost effective fabrication of Al doped 2D ZnO nanosheets based nanogenerator for direct current (DC) power generation is reported in this chapter. The performance of the nanogenerator for DC power generation due to finger tip impacts was studied and subsequently its switching polarity test was also carried out. Output voltage measurements were carried out using the in-house developed experimental setup. Stability test was also carried out to see the robustness of the nanogenerator. Finally, the DC output voltage response of the nanogenerator was studied for its use as an active speed sensor. Chapter 6: The first section summarizes the significant features of the work presented in this thesis. In the second section the scope for carrying out the further work is given.

Aluminium alloys, which are the most widely used materials in the aircraft and aerospace industries, find their applications due to high strength–to-density ratio, resistance to catastrophic fracture, high degree of toughness, fabricability including good weldability and availability. High strength aluminum alloys are used in different forms like sheets, forgings and extruded rods, welded and machined components in the aerospace industry. One major application of the aluminium alloys in the space sector is in the launch vehicle and satellite sub-systems. The Indian Space Research Organization has met major challenges of indigenization of suitable aluminium alloys, for example, Al-Cu alloys (like AA2219) and Al–Zn-Mg alloys (like AA7075 and AFNOR 7020). Many failures of the metallic sub-systems made of different grades of aluminum alloys have confirmed that high levels of residual stresses and unacceptable microstructures have played a role. Crystallographic texture in these materials has a very significant role to play in the performance of these materials in service. The anisotropy in the mechanical properties caused by crystallographic texture would add to the woes of the existing problems of residual stresses and directionality in the microstructure. In this context, a detailed study of crystallographic texture and residual stresses of high strength aluminium alloys is mandatory. It is also important to study the influence of texture on the anisotropy in mechanical properties. The present research programme aims at addressing some of these aspects. The entire work has been divided in three major sections, namely macro and micro texture analysis, non-destructive measurement of residual stresses using X-ray Diffraction (XRD) and the Ultrasonic Testing (UST) and the study of anisotropy in the mechanical properties arising due to the above two factors. The thesis composition is as follows. In Chapter I, a detailed survey of the literature has been presented wherein basic physical metallurgy for different aluminum alloys of interest has been given. Thereafter, details of texture measurement by the X-ray diffraction and Electron Back Scatter Diffraction (EBSD) are presented. This is followed by a detailed review on the texture studies carried out in aluminium alloys under various conditions. Literature review on the two non-destructive methods, namely the X-ray diffraction and ultrasonic method has been carried out in detail. In order to account for microstructural changes, Differential Scanning Calorimetry (DSC) was carried out. Recent work on the mechanical property anisotropy arising due to high degree of mechanical working in aluminium alloys has been reviewed. Chapter II includes the experimental details involved in the course of the present investigation. The procedural details of cold rolling and associated microstructural changes are given in this chapter. This is followed by the texture measurement methods. Experimental details of the bulk texture measurement using the X-ray diffraction and micro texture measurements by the Electron Back Scatter Diffraction (EBSD) in the SEM are described. Details of the texture computation procedure as well as micro texture analysis methods are also presented. Basic principles of the non-destructive methods of measuring residual stresses, viz., the X-ray diffraction and the Ultrasonic testing, including the theory of measurements, are dealt with. Finally, the details of measurements of anisotropy in mechanical properties, including simulation carried out, for the three alloys are delineated. Chapter III deals with the results of the crystallographic texture measurements carried out on the cold rolled and artificially aged aluminium alloys. Results obtained from the pole figure analysis, Orientation Distribution Function (ODF) method and estimation of the various fibres present in the cold rolled material and the volume fraction of the texture components are discussed in detail for the three aluminium alloys. Results of the micro texture measurements using the EBSD are presented, explained and analyzed in detail. A comparison of the inverse pole figures (IPFs), Image Quality (IQ) maps, Misorientation angle, Grain Orientation Spread (GOS), Kernal Average Misorientation (KAM), CSL boundaries, Grain size and Grain boundary character distribution (GBCD) for materials cold rolled to different reduction for each of the alloys are done and analyzed. Conclusions are drawn regarding the evolution of texture from the above analysis. Deformation texture components Cu, Bs and S increase from the starting material as the rolling percentage increases. On the other hand, recrystallization texture components of Goss and Cube are observed to be weak. AFNOR 7020 developed the strongest texture followed by the AA7075 and AA2219 alloys. The Bs component is stronger in AFNOR 7020 alloy. This is attributed to the shear banding. Average KAM value increases as the cold working in the material increases confirming that the material contains high dislocation density at higher working percentages. Chapter IV deals with residual stresses in the aluminium alloys. Measurement of residual stresses has been carried out on the same sheets and plates, wherever it was possible, using the two methods. The residual stresses have been measured in two mutually perpendicular directions of the aluminium alloy sheets. Residual stress measurements by the ultrasonic method using the Critically Refracted Longitudinal (LCR) wave technique is also used to measure the subsurface stresses non-destructively. Acousto Elastic Coefficients (AEC) is determined for the alloys, in uniaxial tension. Using the AEC for the alloys, the RS at a depth of 3mm are evaluated using a 2MHz probe. Results of the stresses measured by the two methods have been discussed. The trends and anisotropy in the stress values due to texture are discussed and compared with the literature available. Surface residual stresses by the XRD method show compressive stresses at a majority of the locations. Residual stresses measured by the ultrasonic technique, which has a depth of penetration of about 3mm, have shown tensile stresses on many locations. Residual stresses are influenced by the crystallographic texture. Anisotropy in stress values in the longitudinal and transverse directions is demonstrated. In Chapter V, the anisotropy in mechanical properties for the three alloys is discussed in detail. The anisotropy in the three directions, namely the parallel, transverse and 45 deg orientation to the rolling directions is evaluated. The Lankford parameter, otherwise known as Plastic Anisotropy Ratio “r”, has been measured from the tensile tests of the alloy samples in the cold rolled conditions. These have been compared with the computed “r” from the XRD ODF data using the VPSC simulations and found to be qualitatively matching. These trends are discussed with the available literature on the anisotropy of the mechanical properties for aluminium alloys. Samples subjected to high cold rolling show anisotropy of UTS, YS and ‘n’ values. Experimentally measured “r” values in all the deformation conditions match the trend qualitatively with the simulated ones. The maximum anisotropy was observed at 45o orientation to the rolling direction in all the three alloys. Chapter VI gives the summary of the results from the study and the suggestions for future work.