Microstructural Evolution in Al-Ti Multilayered Film with Annealing

1999 ◽  
Vol 5 (S2) ◽  
pp. 836-837
Author(s):  
R. Mitra ◽  
W.A. Chiou ◽  
A.Madan ◽  
R. Hoffman ◽  
J.R. Weertman
Keyword(s):  
Magnetron Sputtering ◽  
Ingot Metallurgy ◽  
Multilayered Film ◽  
Multilayered Structures ◽  
Multilayered Films ◽  
Specific Strength ◽  
The Past ◽  
High Specific Strength ◽  
Significant Interest ◽  
Deposited Film

There has been a significant interest in the development of dispersion-hardened aluminum for many years for high specific strength and modulus. Such materials are usually processed by powder or ingot metallurgy routes. In this study, Al3 Ti dispersion hardened Al was obtained by annealing Al-Ti multilayers. Al-Ti multilayered films have been characterized in the past by observing the structure of the layers, as well as tensile properties and hardness. This paper reports the structure of Al-Ti multilayers and the evolution of matrix and dispersoid microstructure on annealing.The Al-Ti multilayered structures were prepared by magnetron sputtering using Al and Ti as targets and either Si (100) or NaCl as substrates. The bi-layer thickness was maintained around 16 nm with Ti constituting 12% of the total. The substrate was alternately moved below the Al and Ti targets for the purpose of deposition. The as-deposited film on the substrate and NaCl salts were annealed at 400°C for periods between 1 and 24 h in a vacuum (10−5 torr) furnace.

Precipitation in Al-Li-Cu Alloys

1981 ◽  
Vol 39 ◽  
pp. 44-45
Author(s):  
J. E. O'Neal ◽  
K. K. Sankaran
Keyword(s):  
Electron Microscopy ◽  
Age Hardening ◽  
Precipitation Behavior ◽  
Zone Formation ◽  
Specific Strength ◽  
Hardening Behavior ◽  
Cu Alloys ◽  
High Specific Strength ◽  
Transmission Electron ◽  
Structural Applications

Al-Li-Cu alloys combine high specific strength and high specific modulus and are potential candidates for aircraft structural applications. As part of an effort to optimize Al-Li-Cu alloys for specific applications, precipitation in these alloys was studied for a range of compositions, and the mechanical behavior was correlated with the microstructures.Alloys with nominal compositions of Al-4Cu-2Li-0.2Zr, Al-2.5Cu-2.5Li-0.2Zr, and Al-l.5Cu-2.5Li-0.5Mn were argon-atomized into powder at solidification rates ≈ 103°C/s. Powders were consolidated into bar stock by vacuum pressing and extruding at 400°C. Alloy specimens were solution annealed at 530°C and aged at temperatures up to 250°C, and the resultant precipitation was studied by transmission electron microscopy (TEM).The low-temperature (≲100°C) precipitation behavior of the Al-4Cu-2Li-0.2Zr alloy is a combination of the separate precipitation behaviors of Al-Cu and Al-Li alloys. The age-hardening behavior at these temperatures is characteristic of Guinier-Preston (GP) zone formation, with additional strengthening resulting from the coherent precipitation of δ’ (Al3Li, Ll2 structure), the presence of which is revealed by the selected-area diffraction pattern (SADP) shown in Figure la.

scholarly journals Surface Stoichiometry and Depth Profile of Tix-CuyNz Thin Films Deposited by Magnetron Sputtering

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3191
Author(s):  
Arun Kumar Mukhopadhyay ◽  
Avishek Roy ◽  
Gourab Bhattacharjee ◽  
Sadhan Chandra Das ◽  
Abhijit Majumdar ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Film Surface ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Relative Composition ◽  
Transmission Electron ◽  
Deposited Film ◽  
Deposited Films

We report the surface stoichiometry of Tix-CuyNz thin film as a function of film depth. Films are deposited by high power impulse (HiPIMS) and DC magnetron sputtering (DCMS). The composition of Ti, Cu, and N in the deposited film is investigated by X-ray photoelectron spectroscopy (XPS). At a larger depth, the relative composition of Cu and Ti in the film is increased compared to the surface. The amount of adventitious carbon which is present on the film surface strongly decreases with film depth. Deposited films also contain a significant amount of oxygen whose origin is not fully clear. Grazing incidence X-ray diffraction (GIXD) shows a Cu3N phase on the surface, while transmission electron microscopy (TEM) indicates a polycrystalline structure and the presence of a Ti3CuN phase.

scholarly journals Structure and Characterization of TiC/GLC Multilayered Films with Various Bilayers Periods

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 787
Author(s):  
Weiqi Wang ◽  
Xiaoming Ling ◽  
Rui Wang ◽  
Wenhao Nie ◽  
Li Ji ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Chemical Compositions ◽  
Closed Field ◽  
Multilayered Structures ◽  
Multilayered Films ◽  
Sputtering Deposition ◽  
X Ray ◽  
Mechanical And Tribological Properties ◽  
Self Organizing

The spontaneously self-organizing multilayered graphite-like carbon (denoted as GLC) /TiC films with various bilayer periods in the range of 13.3–17.5 nm were deposited on silicon and 1Cr18Mn8Ni5N stainless steel substrates using closed field magnetron sputtering deposition facility. The microstructures and chemical compositions of the prepared multilayered films were characterized by scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy respectively. The self-organizing multilayered structures in all of the films consisted of titanium carbide layers and sp2-rich carbon layers periodically alternate arrangement. The TiC contents and bilayer periods of the multilayered films can be controlled by means of adjusting of sputtering current of graphite target. Furthermore, the mechanical and tribological performances of the prepared films were appraised by nano-indentor, scratch measures, and ball-on-plate tribometer respectively. The results indicated that multilayer structure endowed the as-deposited TiC/GLC films outstanding mechanical and tribological properties, especially the multilayer film with 15.9 nm bilayer period deposited at 10 A sputtering current showed the excellent adhesion strength and hardness; Simultaneously it also exhibited the lowest average friction coefficient in the humid environment owing to its high content of sp2 hybrid carbon.

Influence of the Flux Ratio N2/Ar on the Formation of Mo-N Modification Layers on Ti6Al4V by Plasma Reactive Sputtering

2009 ◽  
Vol 610-613 ◽  
pp. 1128-1131
Author(s):  
Xiu Yan Li ◽  
Ying Zhang ◽  
Bin Tang ◽  
Zhong Xu
Keyword(s):  
Substrate Surface ◽  
Surface Hardness ◽  
Flux Ratio ◽  
Reactive Sputtering ◽  
Load Bearing Capacity ◽  
Specific Strength ◽  
The Poor ◽  
High Specific Strength ◽  
Composition Structure ◽  
Oriented Parallel

Ti6Al4V alloy is promising biology material with outstanding properties of low density, high specific strength, and exceptional corrosion resistance. However, one of its disadvantages is the poor tribological property. In this paper Mo-N hard surface modification layers were formed on Ti6Al4V at 900°C substrate temperature by plasma reactive sputtering. The flux ratio N2/Ar is an important parameter and its influence on the composition, structure and hardness of the Mo-N layers is studied. The Mo-N layers are duplex layers, composed of diffusing layer and surface coating. The component of Mo and N elements in the diffusing layer changes gradually which can enhance the load-bearing capacity to the coating and ensure the durability of the coating. With the increase of the flux ratio N2/Ar, the content of N element in the Mo-N layers increases. The Mo-N layers were polycrystalline γ- Mo2N with (200) plane oriented parallel to the substrate surface. The surface hardness of the formed layers is in the range HK1330-1430. The hardness of the Mo-N layers increases with the increase of the flux ratio N2/Ar and the reason is that the content of N element in the Mo-N layers increases.

Research Progress of the Surface Oxidation of Titanium and its Alloys

2013 ◽  
Vol 748 ◽  
pp. 188-191
Author(s):  
Hui Jun Yu
Keyword(s):  
Titanium Alloys ◽  
Biomedical Applications ◽  
Influence Factors ◽  
Surface Oxidation ◽  
Research Progress ◽  
Corrosion Resistant ◽  
Specific Strength ◽  
Existing Problems ◽  
High Specific Strength ◽  
Micro Arc Oxidation

Titanium and titanium alloys possess some attractive properties, such as excellent corrosion and erosion resistance, low densities, high specific strength and modulus, enabling them extensively used in aeronautical, marine, chemical and biomedical applications and so on. Nevertheless, Recent years, the corrosion resistance of titanium and titanium alloys is required to elevate in some fields, proper surface modification such as surface oxidation can solve the problems effectively. In this paper, the recent investigations of thermal oxidation and micro-arc oxidation to improve the corrosion resistant of titanium and its alloys are reviewed. The structures, properties and their influence factors of the coatings are analysed systematically. And the existing problems and the future prospect of the further researches is mentioned.

Strengthening Evaluation in a Composite Mg-RE Alloy Using TEM

2011 ◽  
Vol 678 ◽  
pp. 75-84 ◽  
Author(s):  
Marcello Cabibbo
Keyword(s):  
Electron Microscopy ◽  
Metal Matrix ◽  
Room Temperature ◽  
Strengthening Mechanism ◽  
Composite Alloy ◽  
Specific Strength ◽  
High Specific Strength ◽  
Transmission Electron ◽  
Sic Ceramic

Magnesium alloys containing rare earth elements are known to have high specific strength and corrosion resistance. The addition of SiC ceramic particles makes the metal matrix composite stronger with better wear and creep resistance and a still good machinability. The role of the reinforcement particles to the enhanced strength can be quantitatively evaluated using transmission electron microscopy (TEM). This paper presents a quantitative strengthening evaluation in a SiC Mg-RE composite alloy. The different contributions were determined by TEM inspections. The microstructure strengthening mechanism was studied after room temperature compression specimens. The way of combining the different contributions and the comparison to the measured yield stress, is also discussed and justified.

High Specific Strength Carbon Foam Prepared from Sucrose and Multi-Walled Carbon Nanotube

2015 ◽  
Vol 830-831 ◽  
pp. 545-548
Author(s):  
Rajaram Narasimman ◽  
Sujith Vijayan ◽  
Kuttan Prabhakaran
Keyword(s):  
Compressive Strength ◽  
Carbon Nanotube ◽  
Cellular Structure ◽  
Carbon Foam ◽  
Specific Strength ◽  
High Specific Strength ◽  
Multi Walled Carbon Nanotube ◽  
Uniform Dispersion ◽  
Carbon Foams ◽  
Maximum Compressive Strength

Multi-walled carbon nanotube (MWNT) reinforced carbon foams were prepared by thermo-foaming of MWNT dispersions in molten sucrose followed by dehydration and carbonization. The rheological studies showed that the uniform dispersion of MWNT was achieved up to 1.5 wt.%. The carbon foams showed cellular structure. The density of the carbon foams increased with an increase in the MWNT concentration up to 0.25 wt.% and then remained more or less constant. The maximum compressive strength of 4.9 MPa was achieved at the MWNT concentration of 0.5 wt.%.

scholarly journals Pediatric Integrative Medicine: Vision for the Future

Children ◽  
2018 ◽  
Vol 5 (8) ◽  
pp. 111 ◽  
Author(s):  
Anna Esparham ◽  
Sanghamitra Misra ◽  
Erica Sibinga ◽  
Timothy Culbert ◽  
Kathi Kemper ◽  
...  
Keyword(s):  
Integrative Medicine ◽  
Professional Education ◽  
Chronic Conditions ◽  
Pediatric Population ◽  
Family Education ◽  
Pediatric Care ◽  
The Past ◽  
Significant Interest ◽  
Important Time ◽  
Ecologically Sustainable

Pediatric integrative medicine (PIM) is of significant interest to patients, with 12% of the general pediatric population and up to 80% of children with chronic conditions using PIM approaches. The field of PIM has evolved over the past 25 years, approaching child health with a number of guiding principles: preventive, context-centered, relationship-based, personalized, participatory, and ecologically sustainable. This manuscript reviews important time points for the field of PIM and reports on a series of meetings of PIM leaders, aimed at assessing the state of the field and planning for its future. Efforts in the first decade of the 2000s led to increased visibility in academic and professional pediatric organizations and through international listservs, designed to link those interested in and practicing PIM, all of which continue to flourish. The PIM leadership summits in recent years resulted in specific goals to advance PIM further in the following key areas: research, clinical practice, professional education, patient and family education, and advocacy and partnerships. Additionally, goals were developed for greater expansion of PIM professional education, broader support for pediatric PIM research, and an expanded role for PIM approaches in the provision of pediatric care.

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