Designing Joints with Graded Layers

2012 ◽  
pp. 49-59
Author(s):  
J. Stamile ◽  
I. E. Reimanis ◽  
J. Chapa-Cabrera
Keyword(s):  
Graded Layers

scholarly journals MULTILAYER COATINGS Ti/TiN, Cr/CrN AND W/WN DEPOSITED BY MAGNETRON SPUTTERING FOR IMPROVEMENT OF ADHESION TO BASE MATERIALS

2015 ◽  
Vol 55 (6) ◽  
pp. 388 ◽  
Author(s):  
Jakub Horník ◽  
Stanislav Krum ◽  
David Tondl ◽  
Maxim Puchnin ◽  
Pavel Sachr ◽  
...  
Keyword(s):  
Functionally Graded Materials ◽  
Scratch Test ◽  
Functionally Graded ◽  
Point Of View ◽  
Multilayer Coatings ◽  
Graded Materials ◽  
Protective Function ◽  
Base Materials ◽  
Graded Layers ◽  
Graded Material

The paper deals with evaluation of single and multilayer layer PVD coatings based on Cr and Ti widely used in tool application. Additionally, W and WN based coating which are not so widespread were designed and deposited as functionally graded material. The coatings properties were evaluated from the point of view of hardness and adhesion. The hardness measuring was carried out using nanoindentation method. The scratch test was performed to test adhesion. Moreover, the presence of metallic interlayer in functionally graded materials further increases the coating adhesion by gradually approaching its composition to the substrate. Coatings consisting of W and WN have showed very good adhesion. With regard to the results of the scratch test, the multilayer coatings of CrN, TiN and WN have increased adhesion and can be assumed to have their protective function improved. Results will be appliedin development of functionally graded layers for functionally graded materials.

Advances in the Characterization of Compositionally-graded Layers in Amorphous Semiconductor Solar Cells by Real Time Spectroellipsometry

1996 ◽  
Vol 420 ◽  
Author(s):  
R. W. Collins ◽  
Sangbo Kim ◽  
Joohyun Koh ◽  
J. S. Burnham ◽  
Lihong Jiao ◽  
...  
Keyword(s):  
Solar Cells ◽  
Real Time ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Interface Layer ◽  
Open Circuit ◽  
Amorphous Semiconductor ◽  
Deposition Parameters ◽  
Gas Flow Ratio ◽  
Graded Layers

AbstractWe have developed a real time spectroellipsometry data analysis procedure that allows us to characterize compositionally- graded amorphous semiconductor alloy thin films prepared by plasma-enhanced chemical vapor deposition (PECVD). As an example, we have applied the analysis to obtain the depth-profile of the optical gap and alloy composition with ≤15 Å resolution for a hydrogenated amorphous silicon-carbon alloy (a-Si1−xCx:H) film prepared by continuously varying the gas flow ratio z=[CH4]/{[CH4]+[SiH4]} in the PECVD process. The graded layer has been incorporated at the p/i interface of widegap a-Si1−xCx:H (x∼0.05) p-i-n solar cells, and consistent improvements in open-circuit voltage have been demonstrated. The importance of the graded-layer characterization is the ability to relate improvements in device performance directly to the physical properties of the interface layer, rather to the deposition parameters with which they were prepared.

Temperature-Dependent Vibration of Various Types of Sandwich Beams with Porous FGM Layers

2020 ◽  
pp. 2150016
Author(s):  
Mohsen Rahmani ◽  
Sajjad Dehghanpour
Keyword(s):  
Thermal Stresses ◽  
Equations Of Motion ◽  
Functionally Graded ◽  
Geometrical Parameters ◽  
Type I ◽  
Sandwich Beams ◽  
Temperature Dependent ◽  
The Core ◽  
Graded Layers ◽  
Lagrange Strain

By using a high order sandwich beams theory which is modified by considering the transverse flexibility of the core, free vibration characteristics of two models of sandwich beams are studied in this paper. In type-I, functionally graded layers coat a homogeneous core, and in type-II, an FG core is covered by homogeneous face sheets. To increase the accuracy of the model of the FGM properties, even and uneven porosity distributions are applied, and all materials are considered temperature-dependent. Nonlinear Lagrange strain and thermal stresses of the face sheets and in-plane strain of the core are considered. To obtain the governing equations of motion, Hamilton’s principle is used and a Galerkin method is used to solve them for simply supported and clamped boundary conditions. To verify the results of this study, they are compared with the results of literatures. Also, the effect of variation of temperature, some geometrical parameters and porosities on the frequency are studied.

Dynamic analysis of three-layer cylindrical shells with fractional viscoelastic core and functionally graded face layers

2020 ◽  
pp. 107754632096622
Author(s):  
Meisam Shakouri ◽  
Mohammad Reza Permoon ◽  
Abdolreza Askarian ◽  
Hassan Haddadpour
Keyword(s):  
Natural Frequency ◽  
Equations Of Motion ◽  
Cylindrical Shells ◽  
Ritz Method ◽  
Shear Deformation Theory ◽  
Core Layer ◽  
Functionally Graded ◽  
Viscoelastic Layer ◽  
Viscoelastic Core ◽  
Graded Layers

Natural frequency and damping behavior of three-layer cylindrical shells with a viscoelastic core layer and functionally graded face layers are studied in this article. Using functionally graded face layers can reduce the stress discontinuity in the face–core interface that causes a catastrophic failure in sandwich structures. The viscoelastic layer is expressed using a fractional-order model, and the functionally graded layers are defined by a power law function. Assuming the classical shell theory for functionally graded layers and the first-order shear deformation theory for the viscoelastic core, equations of motion are derived using Lagrange’s equation and then solved via Rayleigh–Ritz method. The obtained results are validated with those in the literature, and finally, the effects of some geometrical and material parameters such as length-to-radius ratio, functionally graded properties, radius and thickness of viscoelastic layer on the natural frequency, and loss factor of the system are considered, and some conclusions are drawn.

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