scholarly journals Computational techniques for the evaluation of inhomogeneity parameters on transient conduction in functionally graded layers

2019 ◽  
Vol 11 (3) ◽  
pp. 428-444
Author(s):  
Mehmet Nurullah Balci ◽  
Bariş Sabuncuoğlu
Keyword(s):  
Functionally Graded ◽  
Computational Techniques ◽  
Graded Layers ◽  
Transient Conduction

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.

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.

Investigation for the Fracture Process of WCp/Cu Functionally Graded Materials under Three-Point-Bending

2013 ◽  
Vol 683 ◽  
pp. 17-20
Author(s):  
Hai Ting Xia ◽  
Rong Xin Guo ◽  
Feng Yan ◽  
Hai Yu ◽  
Yu Bo Zhang
Keyword(s):  
Powder Metallurgy ◽  
Functionally Graded Materials ◽  
Fracture Process ◽  
Bottom Layer ◽  
Functionally Graded ◽  
Graded Materials ◽  
Bending Tests ◽  
Bending Performance ◽  
Three Point Bending ◽  
Graded Layers

In this paper, the fracture process of WCp/Cu functionally graded materials(FGMs) was investigated. The used materials were fabricated by powder metallurgy using tungsten carbide(WC) particles and copper(Cu) matrix, and had functionally graded layers. In order to investigate the fracture process of the FGM, three-point-bending tests of rectangular specimens were carried out. From the results, it can be seen that the bending performance of FGM structures with increasing WC content from head layer to the bottom layer excels that of FGM structures with decreasing WC content in three-point-bending tests.

Indentation Responses of Functionally-Graded Al2TiO5- Based Ceramics

2011 ◽  
Vol 239-242 ◽  
pp. 171-174
Author(s):  
Z Oo ◽  
I.M Low
Keyword(s):  
Fracture Resistance ◽  
Mechanical Performance ◽  
Functionally Graded ◽  
Resistant Material ◽  
High Melting Point ◽  
Aluminium Titanate ◽  
Low Thermal Expansion ◽  
Die Pressing ◽  
Graded Layers ◽  
Tailored Design

Aluminium titanate, Al2TiO5 (AT) with the pseudobrookite structure is the only compound in the alumina-titania system. It is an excellent refractory and thermal shock resistant material due to its relatively low thermal expansion coefficient (1 ´10-6 °C –1) and high melting point (1860°C). However, its low mechanical strength, hardness and fracture resistance together with susceptibility to decomposition in the temperature range 900–1200°C has limited its wider application. In this paper, the innovative tailored design of functionally- graded Al2TiO5 – based ceramics system was presented. This involves the use of a vacuum heat-treatment or die-pressing to form hard graded layers of alumina on Al2TiO5. These hard outer layers will provide hardness and wear resistance to protect the softer but damage resistant underlayers. The results will also explore unresolved issues concerning the effect of graded interfaces on their physical and mechanical performance properties.

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