The critical role of boron doping in the thermoelectric and mechanical properties of nanostructured α-MgAgSb

2018 ◽  
Vol 6 (36) ◽  
pp. 9821-9827 ◽  
Author(s):  
Weihong Gao ◽  
Xiaoyang Yi ◽  
Bo Cui ◽  
Zhenyou Wang ◽  
Jin Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Valence Band ◽  
Critical Role ◽  
Boron Doping ◽  
Thermoelectric Performance ◽  
Micro Hardness ◽  
Solution Strengthening ◽  
Hardness Values

The ineffectiveness of boron doping to enhance thermoelectric performance lied in the introduced perturbation to the valence band. Due to the significant solution strengthening by boron doping, the micro-hardness values of α-MgAgSb have been largely increased.

Dislocations Induced by Heavy Boron Doping of Silicon

1991 ◽  
Vol 49 ◽  
pp. 814-815
Author(s):  
X. J. Ning ◽  
P. Pirouz
Keyword(s):  
Mechanical Properties ◽  
Critical Role ◽  
Boron Doping ◽  
Boron Diffusion ◽  
Boron Doped ◽  
Chemical Etch ◽  
Etch Stop

Diffusion-induced dislocations in silicon have long been of interest in semiconducting devices. Several investigations concerning the dislocations induced by doping of Si were carried out during the early sixties. However, there are still a number of unresolved questions concerning this problem. Because the boron doped chemical etch-stop technique is widely used in the fabrication of microsensors, new interest has arisen in the role of dislocations induced by boron diffusion and the behavior of these dislocations on the mechanical properties of microsensors. The doping of Si in this technique is heavy (>5x1019cm-3) and, consequently, the density of induced dislocations in the wafer is large. The dislocations will probably then play a critical role on the mechanical properties of thin Si wafers used in the etch-stop technique.

Micro-Hardness and Morphology of LDPE Influenced by Beta Radiation

2014 ◽  
Vol 606 ◽  
pp. 253-256 ◽  
Author(s):  
Martin Ovsik ◽  
Petr Kratky ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hardness Test ◽  
Polymer Materials ◽  
Beta Radiation ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Depth Sensing ◽  
Surface Layers ◽  
Hardness Values ◽  
Different Doses

This article deals with the influence of different doses of Beta radiation to the structure and mico-mechanical properties of Low-density polyethylene (LDPE). Hard surface layers of polymer materials, especially LDPE, can be formed by radiation cross-linking by β radiation with doses of 33, 66 and 99 kGy. Material properties created by β radiation are measured by micro-hardness test using the DSI method (Depth Sensing Indentation). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the LDPE tested. The highest values of micro-mechanical properties were reached at radiation dose of 66 and 99 kGy, when the micro-hardness values increased by about 21%. The changes were examined and confirmed by X-ray diffraction.

scholarly journals Experimental Evaluation of Mechanical Properties of Friction Welded Dissimilar Steels under Varying Axial Pressures

2016 ◽  
Vol 66 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Amit Handa ◽  
Vikas Chawla
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Failure Analysis ◽  
Friction Welding ◽  
Experimental Evaluation ◽  
Micro Hardness ◽  
Aisi 304 ◽  
Torsional Strength ◽  
Hardness Values

AbstractThe present study emphasizes on joints two industrially important materials AISI 304 with AISI 1021steels, produced by friction welding have been investigated. Samples were welded under different axial pressures ranging from 75MPa to 135MPa, at constant speed of 920rpm. The tensile strength, torsional strength, impact strength and micro hardness values of the weldments were determined and evaluated. Simultaneously the fractrography of the tensile tested specimens were carried out, so as to understand the failure analysis. It was observed that improved mechanical properties were noticed at higher axial pressures. Ductile failures of weldments were also observed at 120MPa and 135MPa axial pressures during fractography analysis.

scholarly journals Application of the plasticity characteristic determined by the indentation technique for evaluation of mechanical properties of coatings: I. specific features of the test method procedure

2004 ◽  
Vol 36 (1) ◽  
pp. 27-41 ◽  
Author(s):  
A.V. Byakova ◽  
Yu.V. Milman ◽  
A.A. Vlasov
Keyword(s):  
Mechanical Properties ◽  
Indentation Load ◽  
Test Method ◽  
Simplified Model ◽  
Micro Hardness ◽  
Properties Of Coatings ◽  
Modified Model ◽  
Plasticity Characteristic ◽  
Measurement Results ◽  
Hardness Values

Specific features of the test method procedure capable for determining the plasticity characteristic dH by indentation of inhomogeneous coatings affected by residual stress was clarified. When the value of the plasticity characteristic for coating was found to be as great as dH > 0.5 a simplified model was found to be reasonably adequate, while a modified model assumed compressibility of the deformation core beneath indentation. The advantage of the modified approach compared to the simplified one was grounded experimentally only if the elastic deformation for coating becomes greater than ?e ? 3.5%, resulting in the decrease of plasticity characteristic dH < 0.5. To overcome non accuracy caused by the effect of the scale factor on measurement results a comparison of different coatings was suggested using stabilized values of the plasticity characteristic dH determined under loads higher than critical, P ? Pc, ensuring week dependence of micro hardness values on the indentation load.

The Critical Role of Dopant Cations in Electrical Conductivity and Thermoelectric Performance of n-Doped Polymers

2020 ◽  
Vol 142 (36) ◽  
pp. 15340-15348 ◽  
Author(s):  
Yang Lu ◽  
Zi-Di Yu ◽  
Yi Liu ◽  
Yi-Fan Ding ◽  
Chi-Yuan Yang ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Critical Role ◽  
Thermoelectric Performance ◽  
Doped Polymers

scholarly journals Effect of Beta Low Irradiation Doses on the Filled PA66 Measured by Micro-Indentation Test

2014 ◽  
Vol 1025-1026 ◽  
pp. 415-418
Author(s):  
Martin Ovsik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Martin Reznicek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Fibers ◽  
Indentation Test ◽  
Radiation Doses ◽  
Micro Hardness ◽  
Polyamide 66 ◽  
Depth Sensing ◽  
Micro Indentation ◽  
Hardness Values ◽  
Different Doses

The presented article deals with the research of micro-mechanical properties in the surface layer of modified Polyamide 66 filled by 30% of glass fibers. These micro-mechanical properties were measured by the Depth Sensing Indentation - DSI method on samples which were non-irradiated and irradiated by different doses of the β - radiation. Radiation doses used were 0, 15, 30 and 45 kGy for filled Polyamide 66 with the 6% cross-linking agent (triallyl isocyanurate). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the polyamide 66 tested. The highest values of micro-mechanical properties were reached at radiation dose of 30 kGy, when the micro-hardness values increased by about 64%. The aim of the article is to find out the influence of the radiation on the micro-hardness of the modified glass fiber-filled Polyamide 66 (PA66).

scholarly journals Green Sand Mould Production of Aluminum Alloy Bimetallic Castings

2020 ◽  
Vol 13 (3) ◽  
Author(s):  
B.V. Omidiji ◽  
B.O. Malomo ◽  
A. Aronsoro ◽  
D.A. Adetan
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Hot Spots ◽  
Al Alloys ◽  
Gating System ◽  
Green Sand ◽  
Pouring Temperature ◽  
Sand Mould ◽  
Hardness Values

A green sand moulding system was applied to produce alumunum alloy bimetallic castings. Al alloys 6101 and 242 were combined in the production of the bimetals. Mould firing temperature, pouring temperature and grain fineness number taken at three levels were the parameters used in the study. This was done to know the number of times the experiments would be run using L9 orthogonal array of Taguchi’s approach to design of experiment. Nine experiments were conducted in all, taking into cognisance the role of design of gating system for each of the castings to avoid turbulence. UTS and hardness values were determined as core mechanical properties of the components. There was a down trend of the values as the values of the process parameters increased. However, there were exceptions to this pattern of behaviour perhaps some hot spots were in the castings that exhibited the kind of behaviour.

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