scholarly journals Calculation of Volume Fractions of In Situ TiB and Residual Stress Distributions in Functionally Graded Composite of Ti–TiB–TiB2

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4006
Author(s):  
Youfeng Zhang ◽  
Shasha He ◽  
Wanwan Yang ◽  
Jiangwei Ren ◽  
Haijuan Kong
Keyword(s):  
Residual Stress ◽  
Matrix Composite ◽  
Target Volume ◽  
Functionally Graded ◽  
Gradient Field ◽  
Stress Distributions ◽  
Volume Fractions ◽  
Functionally Graded Composite ◽  
The Matrix ◽  
Graded Material

Ti matrix composite with a polylaminate structure was successfully fabricated via spark plasma sintering (SPS) process. A temperature gradient field (TGF) was obtained during the sintering to form functionally graded material (FGM) in a vacuum under 40 MPa for 5 min. The actual volume fractions of TiB in the matrix were calculated based on the X-ray diffraction pattern. The target volume fractions of TiB were 0%, 20%, 40%, 60%, 80% and 100%. The calculated TiB volume fractions were slightly higher than the target volume fractions in layers 2–4 and lower than the target volume fractions in layers 5–6 and the deviations in layers 4 and 5 were less than 5% of the target volume. Based on the elastic axial symmetry model, the residual stress distributions in the Ti matrix composite with a polylaminate structure were simulated, indicating a relatively low thermal residual stress in the FGM.

scholarly journals Lamb Waves in a Functionally Graded Composite Plate with Nonintegral Power Function Volume Fractions

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Xiaoshan Cao ◽  
Zhen Qu ◽  
Junping Shi ◽  
Yan Ru
Keyword(s):  
Differential Equations ◽  
Lamb Waves ◽  
Variable Coefficients ◽  
Functionally Graded ◽  
Power Functions ◽  
Volume Fractions ◽  
Functionally Graded Composite ◽  
Propagation Behavior ◽  
Graded Material ◽  
Thermal Stress Relaxation

An analytical modelling is carried out to determine the Lamb wave’s propagation behavior in a thermal stress relaxation type functionally graded material (FGM) plate, which is a composite of two kinds of materials. The mechanical parameters depend on the volume fractions, which are nonintegral power functions, and the gradient coefficient is the power value. Based on the theory of elastodynamics, differential equations with variable coefficients are established. We employ variable substitution for theoretical derivations to solve the ordinary differential equations with variable coefficients using the Taylor series. The numerical results reveal that the dispersion properties in some regions are changed by the graded property, the phase velocity varies in a nonlinear manner with the gradient coefficient, nondispersion frequency exists in the first mode, and the set of cutoff frequencies is a union of two series of approximate arithmetic progressions. These results provide theoretical guidance not only for the experimental measurement of material properties but also for their nondestructive testing.

Enhancing the tensile strength of SiC reinforced aluminium- based functionally graded structure through the mixture design approach

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
M. Poornesh ◽  
Shreeranga Bhat ◽  
E.V. Gijo ◽  
Pavana Kumara Bellairu
Keyword(s):  
Tensile Strength ◽  
Composite Structure ◽  
Centrifugal Casting ◽  
Matrix Material ◽  
Stir Casting ◽  
Mixture Design ◽  
Functionally Graded ◽  
Content Type ◽  
Functionally Graded Composite ◽  
The Matrix

PurposeThis article aims to study the tensile properties of a functionally graded composite structure with Al–18wt%Si alloy as the matrix material and silicon carbide (SiC) particles as the reinforcing element. More specifically, the study's primary objective is to optimize the composition of the material elements using a robust statistical approach.Design/methodology/approachIn this research, the composite material is fabricated using a combination of stir casting and the centrifugal casting technique. Moreover, the test specimen required to study the tensile strength are prepared according to the ASTM (American Society for Testing and Materials) standards. Eventually, optimal composition to maximize the tensile property of the material is determined using the mixture design approach.FindingsThe investigation results imply that the addition of the SiC plays a crucial role in increasing the tensile strength of the composite. The optical microstructural images of the composite show the adequate distribution of the reinforcing particles with the matrix. The proposed regression model shows better predictability of tensile strength. In addition, the methodology aids in optimizing the mixture component values to maximize the tensile strength of the produced functionally graded composite structure.Originality/valueLittle work has been reported so far where a hypereutectic Al–Si alloy is considered the matrix material to produce the composite structure. The article attempts to make a composite structure by using a combination of stir casting and centrifugal casting. Furthermore, it employs the mixture design to optimize the composition and predict the model of the study, which is one of a kind in the field of material science.

Effective Thermal Conductivity of Functionally Graded Particulate Nanocomposites With Interfacial Thermal Resistance

2008 ◽  
Vol 75 (5) ◽  
Author(s):  
H. M. Yin ◽  
G. H. Paulino ◽  
W. G. Buttlar ◽  
L. Z. Sun
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Effective Thermal Conductivity ◽  
Functionally Graded ◽  
Interfacial Thermal Resistance ◽  
Conductivity Distribution ◽  
Consistent Model ◽  
The Matrix ◽  
Graded Material ◽  
Perfect Interface

By means of a fundamental solution for a single inhomogeneity embedded in a functionally graded material matrix, a self-consistent model is proposed to investigate the effective thermal conductivity distribution in a functionally graded particulate nanocomposite. The “Kapitza thermal resistance” along the interface between a particle and the matrix is simulated with a perfect interface but a lower thermal conductivity of the particle. The results indicate that the effective thermal conductivity distribution greatly depends on Kapitza thermal resistance, particle size, and degree of material gradient.

TiN/Al2O3 Functionally Graded Material Fabricated by In Situ Reaction

2008 ◽  
Vol 368-372 ◽  
pp. 1835-1837
Author(s):  
Jian Hua Nie ◽  
Ya Wei Li ◽  
Hao Yan ◽  
Yong He Liang ◽  
Yuan Bing Li
Keyword(s):  
Phase Composition ◽  
Functionally Graded Material ◽  
Functionally Graded ◽  
Initial Reaction ◽  
Tio2 Powder ◽  
Functionally Graded Composite ◽  
Epma Analysis ◽  
Graded Material ◽  
Al Powder

TiN/Al2O3 functionally graded composite was fabricated by in-situ aluminothermic reduction of TiO2 in coke bed from mixtures of TiO2 powder and metal Al powder. The reaction process, phase composition, and microstructure of sample treated at 1500°C for 3h were analyzed by XRD, SEM and EPMA. The results indicated that the thermite reduction of TiO2 involves several transitional stages and its initial reaction temperature is lowered by prior reaction between Al and TiO2. EPMA analysis showed that the TiN/Al2O3 ratio in TiN/Al2O3 functionally graded material products changes gradually across the samples without distinct interface between the different layers. The microstructure of the composite changes gradually, and the size of TiN grains increases from the verge region of samples to the centre of samples. These results above were in agreement with thermodynamic analysis.

scholarly journals Thermal and Mechanical Analyses of Dry Clutch Disk made of Functionally Graded Material.

2021 ◽  
Author(s):  
Ibrahim Ahmed Ibrahim Ali ◽  
Saeed Asiri
Keyword(s):  
Silicon Carbide ◽  
Matrix Composite ◽  
Aluminum Matrix ◽  
Friction Material ◽  
Aluminum Matrix Composite ◽  
Functionally Graded ◽  
High Wear Resistance ◽  
Graded Material ◽  
The Common ◽  
Dry Clutch

Abstract This paper presents an innovative utility of Functionally Graded Aluminum Matrix Composite (FGAMC) with Silicon Carbide as a friction material in clutches since having an acceptable friction coefficient and high wear resistance. FGAMC’s properties were calculated using rule-of-mixture and power law, represented by layered geometry. FGAMC’s behavior is examined considering statics, dynamics, thermal and wear. Analyses were done using Finite Element method, by ANSYS. Results are discussed by comparing FGAMC’s clutch to Aluminum matrix composite with 20% of Silicon Carbide clutch and E-glass clutch. Clutches design based on the common size and working conditions of clutches in mid-size and heavy automobiles. Most analyses revels FGAMC’s clutch has higher strain than AMC’s clutch with less deformation in thickness direction and less stresses. FGAMC’s clutch has higher mass leading to lower first natural frequency but with low resulted deformations. Transient analyses showed 10 times fewer maximum deformations for FGAMC’s clutch than AMC and E-glass with lower strains and higher stress but in much less area for FGAMC’s clutch. Wear which indicates working life of a clutch, have been studied using Archard Wear Equation in ANSYS, FGAMC’s clutch has 10 times lower wear with much less affected area compared to AMC and E-glass. Thermal analysis results of the three clutches are close to each other with 0.07 watts between FGAMC’s and AMC’s clutches, and 0.03 watts between FGAMC’s and E-Glass’s clutches.

scholarly journals Toward Variability Characterization and Statistic Models’ Constitution for the Prediction of Exponentially Graded Plates’ Static Response

2018 ◽  
Vol 2 (4) ◽  
pp. 59 ◽  
Author(s):  
Rafael Rosa ◽  
Maria Loja ◽  
Alda Carvalho
Keyword(s):  
Prediction Models ◽  
Shear Deformation Theory ◽  
Sampling Technique ◽  
Latin Hypercube Sampling ◽  
Functionally Graded ◽  
Geometrical Parameters ◽  
Functionally Graded Composite ◽  
Static Responses ◽  
Graded Material ◽  
Exponentially Graded

Functionally graded composite materials may constitute an advantageous alternative to engineering applications, allying a customized tailoring capability to its inherent continuous properties transition. However, these attractive characteristics must account for the uncertainty that affects these materials and their structures’ physical quantities. Therefore, it is important to analyze how this uncertainty will modify the foreseen deterministic response of a structure that is built with these materials, identifying which of the parameters are responsible for a greater impact. To pursue this main objective, the material and geometrical parameters that characterize a plate made of an exponentially graded material are generated according to a random multivariate normal distribution, using the Latin hypercube sampling technique. Then, a set of finite element analyses based on the first-order shear deformation theory are performed to characterize the linear static responses of these plates, which are further correlated to the input parameters. This work also considers the constitution of statistic models in order to allow their use as alternative prediction models. The results show that for the plates that were analyzed, the uncertainty associated with the elasticity modulus of both phases is mainly responsible for the maximum transverse deflection variability. The effectiveness of the statistical models that are built are also shown.

FABRICATION AND RESIDUAL STRESS CHARACTERIZATION OF SQUEEZE INFILTRATED Al18B4O33/Mg FUNCTIONALLY GRADED MATERIAL

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1485-1490
Author(s):  
WOOK JIN LEE ◽  
JUN SEONG YANG ◽  
YONG HA PARK ◽  
BONG GYU PARK ◽  
IK MIN PARK ◽  
...  
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Numerical Models ◽  
Functionally Graded ◽  
Mechanical Parameters ◽  
Squeeze Infiltration ◽  
Graded Material ◽  
Infiltration Technique

In this study, three types of functionally graded Al 18 B 4 O 33/ Mg composites which consisted of 2, 3 and 4 layers and where volume fractions of Al 18 B 4 O 33 were gradually changing from 0 to 35% were fabricated using squeeze infiltration technique. The mechanical parameters of each layer were measured for the analysis of residual stress. Elastic finite element numerical models were applied to the analysis of thermal residual stress. The analytic results showed that the residual stresses were significantly decreased in the macrointerface with increasing the number of layer.

Elastic-Plastic Analysis for Functionally Graded Thick-Walled Tube Subjected to Internal Pressure

2016 ◽  
Vol 8 (2) ◽  
pp. 331-352 ◽  
Author(s):  
Libiao Xin ◽  
Guansuo Dui ◽  
Shengyou Yang ◽  
Ying Liu
Keyword(s):  
Internal Pressure ◽  
Yield Criterion ◽  
Functionally Graded ◽  
Power Functions ◽  
Unknown Parameters ◽  
Volume Fractions ◽  
Elastic Plastic ◽  
Graded Material ◽  
Two Phases ◽  
Elastic Plastic Materials

AbstractThe elastic-plastic response of the functionally graded thick-walled tube subjected to internal pressure is investigated by using the relation of the volume average stresses of constituents and the macroscopic stress of composite material in micromechanics. The tube consists of two idealized isotropic elastic-plastic materials whose volume fractions are power functions of the radius. As the internal pressure increases, the deformations of one phase and two phases from elastic to plastic are analyzed. In order to simplify the calculations we assume both materials with the same Poisson's ratio. By using the assumption of a uniform strain field within the representative volume element and the Tresca yield criterion, the theoretical solutions are obtained for the case of two elastic phases and the case of two plastic phases, and the function of the radial displacement is presented for the case with both elastic and plastic phases. The yield criterion of functionally graded material is given in terms of the yield stresses and volume fractions of constituents rather than Young's modulus and yield stress with different unknown parameters of the whole material in the existing papers. Finally we also discuss the position where the plastic deformation first occurs and the conditions for which material first yields in the tube.

Processing of a Graded Ceramic Cutting Tool in the Al2O3-ZrO2-Ti(C,N) System by Electrophoretic Deposition

2005 ◽  
Vol 492-493 ◽  
pp. 705-710 ◽  
Author(s):  
Kim Vanmeensel ◽  
Guy Anné ◽  
Dongtao Jiang ◽  
Jef Vleugels ◽  
Omer Van der Biest
Keyword(s):  
Residual Stress ◽  
Electrophoretic Deposition ◽  
Functionally Graded Material ◽  
Cutting Tool ◽  
Inner Core ◽  
Processing Technique ◽  
Residual Stress Distribution ◽  
Functionally Graded ◽  
Ceramic Cutting Tool ◽  
Graded Material

In this study, the development of a functionally graded material (FGM) with hard outer surfaces and a tougher inner core was envisaged. The applicability of electrophoretic deposition (EPD) for the processing of FGM materials by continuously changing the suspension composition is shown. Optimisation of the colloidal processing technique was combined with hot pressing experiments on homogeneous composites in the Al2O3-ZrO2-Ti(C,N) system in order to create a very hard functionally graded material with beneficial residual stresses. Finally, the residual stress distribution was briefly discussed using an existing analytical model.

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