P-Type and N-Type Bi2Te3/PbTe Functional Gradient Materials for Thermoelectric Power Generation

2007 ◽  
Vol 534-536 ◽  
pp. 1493-1496 ◽  
Author(s):  
Kwang Yong Lee ◽  
Tae Sung Oh
Keyword(s):  
Power Generation ◽  
Thermoelectric Power ◽  
Output Power ◽  
Hot Pressing ◽  
Gradient Material ◽  
Mechanically Alloyed ◽  
Gradient Materials ◽  
Functional Gradient ◽  
Functional Gradient Material ◽  
P Type

The p-type (Bi0.2Sb0.8)2Te3/(Pb0.7Sn0.3)Te functional gradient material (FGM) was fabricated by hot-pressing the mechanically alloyed (Bi0.2Sb0.8)2Te3 and the 0.5 at% Na2Te-doped (Pb0.7Sn0.3)Te powders. Also, the n-type Bi2(Te0.9Se0.1)3/PbTe FGM was processed by hot-pressing the mechanically alloyed Bi2(Te0.9Se0.1)3 and the 0.3 wt% Bi-doped PbTe powders. With △T larger than 300°C, the p-type (Bi0.2Sb0.8)2Te3/(Pb0.7Sn0.3)Te FGM exhibited larger thermoelectric output power than those of the (Bi0.2Sb0.8)2Te3 and the 0.5 at% Na2Te-doped (Pb0.7Sn0.3)Te alloys. For the n-type Bi2(Te0.9Se0.1)3/PbTe FGM, the thermoelectric output power superior to those of the Bi2(Te0.9Se0.1)3 and the 0.3 wt% Bi-doped PbTe was predicted at △T larger than 300°C.

Fabrication of Functional Gradient Materials Electrode and its Application in Micro-EDM

2017 ◽  
Vol 868 ◽  
pp. 151-157
Author(s):  
Xiao Peng Li ◽  
Yuan Gang Wang ◽  
Fu Ling Zhao ◽  
Meng Hua Wu
Keyword(s):  
Electrical Discharge Machining ◽  
Gradient Material ◽  
Homogeneous Material ◽  
Tool Electrode ◽  
Micro Edm ◽  
Gradient Materials ◽  
Functional Gradient ◽  
Micro Electrical Discharge Machining ◽  
Functional Gradient Material ◽  
Edm Process

The concept and the primary preparation method of functional gradient materials are described in this paper. Functional gradient material is prepared as a tool electrode by electrochemical method and its performance is further tested in the micro electrical discharge machining (micro-EDM) experiments. Compared with the homogeneous material electrode, the functional gradient material electrode can effectively inhibit the wearing of the tool electrode and improve the distribution trend of current density during the micro-EDM process. The results disclose the prospects for functional gradient material to be used as tool electrode in the micro-EDM process.

Power generation performance of π-structure thermoelectric device using NaCo2O4 and Mg2Si elements

2013 ◽  
Vol 1490 ◽  
pp. 185-190 ◽  
Author(s):  
Tomoyuki Nakamura ◽  
Kazuya Hatakeyama ◽  
Masahiro Minowa ◽  
Youhiko Mito ◽  
Koya Arai ◽  
...  
Keyword(s):  
Power Generation ◽  
Thermoelectric Power ◽  
Thermoelectric Properties ◽  
Waste Heat ◽  
Maximum Output Power ◽  
Magnesium Silicide ◽  
Thermoelectric Device ◽  
Maximum Output ◽  
Thermoelectric Power Generation ◽  
P Type

ABSTRACTThermoelectric power generation has been attracting attention as a technology for waste heat utilization in which thermal energy is directly converted into electric energy. It is well known that layered cobalt oxide compounds such as NaCo2O4 and Ca3Co4O9 have high thermoelectric properties in p-type oxide semiconductors. However, in most cases, the thermoelectric properties in n-type oxide materials are not as high. Therefore, n-type magnesium silicide (Mg2Si) has been studied as an alternative due to its non-toxicity, environmental friendliness, lightweight property, and comparative abundance compared with other TE systems. In this study, we fabricated π-structure thermoelectric power generation devices using p-type NaCo2O4 elements and n-type Mg2Si elements. The p- and n-type sintering bodies were fabricated by spark plasma sintering (SPS). To reduce the resistance at the interface between elements and electrodes, we processed the surface of the elements before fabricating the devices. The end face of a Mg2Si element was covered with Ni by SPS and that of a NaCo2O4 element was coated with Ag by silver paste and soldering.The thermoelectric device consisted of 18 pairs of p-type and n-type legs connected with Ag electrodes. The cross-sectional and thickness dimensions of the p-type elements were 3.0 mm × 5.0 mm × 7.6 mm (t) and those of the n-type elements were 3.0 mm × 3.0 mm × 7.6 mm (t). The open circuit voltage was 1.9 V and the maximum output power was 1.4 W at a heat source temperature of 873 K and a cooling water temperature of 283 K in air.

scholarly journals Buckling of a composite bar made of a functional-gradient material with an inhomogeneous pre-stress field

2018 ◽  
Vol 226 ◽  
pp. 01014
Author(s):  
Vadim V. Eremeev ◽  
Denis V. Ivashchenko
Keyword(s):  
Stress Field ◽  
Circular Cylinder ◽  
Nonlinear Elasticity ◽  
Linear Instability ◽  
Initial Stresses ◽  
Gradient Material ◽  
Material Inhomogeneity ◽  
Functional Gradient ◽  
Functional Gradient Material ◽  
Graded Material

Within the 3D nonlinear elasticity we discuss the linear instability of a composite bar made of a functially graded material and having initial stresses. The bar consists of two layers which are inflated for a annular wedge of a circular cylinder. We present the linearized boundary0value problem and obtain its non-trivial solutions. The influence of the material inhomogeneity and the initial stresses are discussed.

scholarly journals Understanding the asymmetrical thermoelectric performance for discovering promising thermoelectric materials

2019 ◽  
Vol 5 (6) ◽  
pp. eaav5813 ◽  
Author(s):  
Hangtian Zhu ◽  
Jun Mao ◽  
Zhenzhen Feng ◽  
Jifeng Sun ◽  
Qing Zhu ◽  
...  
Keyword(s):  
Power Generation ◽  
High Temperature ◽  
Thermoelectric Power ◽  
Conversion Efficiency ◽  
Thermoelectric Materials ◽  
The Other ◽  
Thermoelectric Performance ◽  
Cold Side ◽  
P Type ◽  
The Relationship

Thermoelectric modules, consisting of multiple pairs of n- and p-type legs, enable converting heat into electricity and vice versa. However, the thermoelectric performance is often asymmetrical, in that one type outperforms the other. In this paper, we identified the relationship between the asymmetrical thermoelectric performance and the weighted mobility ratio, a correlation that can help predict the thermoelectric performance of unreported materials. Here, a reasonably high ZT for the n-type ZrCoBi-based half-Heuslers is first predicted and then experimentally verified. A high peak ZT of ~1 at 973 K can be realized by ZrCo0.9Ni0.1Bi0.85Sb0.15. The measured heat-to-electricity conversion efficiency for the unicouple of ZrCoBi-based materials can be as high as ~10% at the cold-side temperature of ~303 K and at the hot-side temperature of ~983 K. Our work demonstrates that the ZrCoBi-based half-Heuslers are highly promising for the application of mid- and high-temperature thermoelectric power generation.

System Development of Processing Functional Gradient Material Part by Laser Rapid Prototyping

2013 ◽  
Vol 834-836 ◽  
pp. 1571-1574
Author(s):  
Qun Qin ◽  
Guang Xia Chen
Keyword(s):  
Path Planning ◽  
System Development ◽  
One Dimension ◽  
Gradient Material ◽  
Two Dimension ◽  
Functional Gradient ◽  
Stl File ◽  
Functional Gradient Material ◽  
Planning Methods ◽  
Material Information

The primary goal of this research is the development of software system about functional gradient material process by laser. The system can be divided into several modules such as STL file loading and viewing, model slicing, filling path planning and process controlling. Path planning of FGM area is one key technology of system development because of one path must contain material information of functional gradient material. The material information planning methods of one-dimension and two-dimension functional gradient material were described respectively in this article. The material information of one-dimension FGM changes by layer along Z-axis, and the material information of two-dimension FGM changes by path in X-Y plane, especially, there is different change direction of FGM between inner loop and outer loop.

scholarly journals Dynamic Fracture Analysis of Functional Gradient Material Coating Based on the Peridynamic Method

Coatings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 62 ◽  
Author(s):  
Yu Zhang ◽  
Zhanqi Cheng ◽  
Hu Feng
Keyword(s):  
Elastic Modulus ◽  
Crack Propagation ◽  
Dynamic Fracture ◽  
Gradient Material ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
Functional Gradient ◽  
Damage And Failure ◽  
Functional Gradient Material ◽  
Graded Material

Functional gradient materials (FGMs) have tremendous potential due to their characteristic advantage of asymptotic continuous variation of their properties. When an FGM is used as a coating material, damage and failure of the interface with the substrate component can be effectively inhibited. In order to study the dynamic crack propagation in FGM coatings, a new method, peridynamics (PD), was used in the present study to simulate dynamic fractures of FGM coatings bonded to a homogeneous substrate under dynamic loading. The bond-based PD theory was employed to study crack propagation and branching in the FGM coating. The influences of the coating gradient pattern, loading, and the geometry and size of the structure on crack curving and propagation under impact loading were investigated. The numerical results show that different forms of the elastic modulus of graded material, the geometry of the structure, and the loading conditions have considerate effects on crack propagation in FGM coatings, but a specific form of elastic modulus had a limited effect on the dynamic fracture of FGM coating.

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