scholarly journals Exploration of the Sparck Plasma Sinter Technique for the Manufacture of Implants for Orthopedic Applications: Development of A High-Performance Nbti-Swcnts Nanocomposite Welded Tv6a Alloy and Densification of Preforms

2020 ◽  
Vol 3 (2) ◽  
Keyword(s):  
Carbon Nanotubes ◽  
High Performance ◽  
Biomedical Application ◽  
Coarse Grained ◽  
Joint Interface ◽  
Mechanically Alloyed ◽  
Homogeneous Microstructure ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Change Of Scale

Nanocomposite Ti 50 wt% Nb with and without reinforcement of carbon nanotubes were successfully fabricated by ball milling of Ti, Nb and SWCNTs (single walled carbon nanotubes) nanopowder mixture folloyed by field actived spark plasma sintering process (FASPS) for biomedical application, superconductivity and magnetism in the ITER Project. The use of brittle Ti powder, instead of ductile elemental powder, led to significant increment in the yield of mechanically alloyed powder. The powder consisted of homogeneously distributed nano-sized Ti/Nb particles together with micronsized pure Nb particles. Sintering of the powders under low temperature and pressure conditions (1273 K, 1473 K and P=50 Mpa) resulted in the fine-grained heterogeneous microstructure consisting of α and β phases. On the other hand, sintering at higher temperatures (1473 K) resulted in a relatively coarse-grained chemically homogeneous microstructure with almost complete phase. Coarse-grained homogeneous β NbTi alloy exhibited higher average hardness as compared to that of heterogeneous fine grained microstructures. An attempt has been made to illustrate the correlation between the microstructural characteristics and mechanical properties of the sintered Ti50Nb compacts. To studies and to develop the influence of SWCNTs on the behavior of the nanocomposite TiNb/SWCNTs and the welding joint interface between TA6V and nanocomposite by sparck plasma sintering. At last, the continuation of the work has been discussed and prepared, planning dynamic flexion tests to measure the NbTi, NbTi/CNTs, NbTi/SWCNTs,/TA6V fatigue limit and developing a computer processing chain in order to customize prostheses respecting patients’ morphology. The fluid ethanchied lubrification of the prosthesis articulation is currently also in study and preparation. Then, a change of scale made possible by the use of an industrial size SPS machine led to the realization of types of blade perform according to patent morphology. These results led to the filing of a patent.

High-Performance Reconfigurable Computing

2019 ◽  
pp. 731-744
Author(s):  
Mário Pereira Vestias
Keyword(s):  
Power Consumption ◽  
Integrated Circuit ◽  
Reconfigurable Computing ◽  
High Performance ◽  
General Purpose ◽  
Reconfigurable Hardware ◽  
Coarse Grained ◽  
Lower Power ◽  
Fine Grained ◽  
Application Specific

High-performance reconfigurable computing systems integrate reconfigurable technology in the computing architecture to improve performance. Besides performance, reconfigurable hardware devices also achieve lower power consumption compared to general-purpose processors. Better performance and lower power consumption could be achieved using application-specific integrated circuit (ASIC) technology. However, ASICs are not reconfigurable, turning them application specific. Reconfigurable logic becomes a major advantage when hardware flexibility permits to speed up whatever the application with the same hardware module. The first and most common devices utilized for reconfigurable computing are fine-grained FPGAs with a large hardware flexibility. To reduce the performance and area overhead associated with the reconfigurability, coarse-grained reconfigurable solutions has been proposed as a way to achieve better performance and lower power consumption. In this chapter, the authors provide a description of reconfigurable hardware for high-performance computing.

High-Performance Reconfigurable Computing

2018 ◽  
pp. 4018-4029
Author(s):  
Mário Pereira Vestias
Keyword(s):  
Power Consumption ◽  
Integrated Circuit ◽  
Reconfigurable Computing ◽  
High Performance ◽  
General Purpose ◽  
Reconfigurable Hardware ◽  
Coarse Grained ◽  
Lower Power ◽  
Fine Grained ◽  
Application Specific

High-Performance Reconfigurable Computing systems integrate reconfigurable technology in the computing architecture to improve performance. Besides performance, reconfigurable hardware devices also achieve lower power consumption compared to General-Purpose Processors. Better performance and lower power consumption could be achieved using Application Specific Integrated Circuit (ASIC) technology. However, ASICs are not reconfigurable, turning them application specific. Reconfigurable logic becomes a major advantage when hardware flexibility permits to speed up whatever the application with the same hardware module. The first and most common devices utilized for reconfigurable computing are fine-grained FPGAs with a large hardware flexibility. To reduce the performance and area overhead associated with the reconfigurability, coarse-grained reconfigurable solutions has been proposed as a way to achieve better performance and lower power consumption. In this chapter we will provide a description of reconfigurable hardware for high performance computing.

Properties of Ultrafine-Grained Tungsten Prepared by Ball Milling and Spark Plasma Sintering

2016 ◽  
Vol 821 ◽  
pp. 399-404 ◽  
Author(s):  
Monika Vilémová ◽  
Barbara Nevrlá ◽  
Zdenek Pala ◽  
Lenka Kocmanová ◽  
Marek Janata ◽  
...  
Keyword(s):  
Ball Milling ◽  
Spark Plasma Sintering ◽  
Ball Mill ◽  
Planetary Ball Mill ◽  
Coarse Grained ◽  
First Wall ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Ultrafine Grained ◽  
Spark Plasma

Tungsten is currently considered as the most suitable plasma facing material for the first wall of a nuclear fusion reactor. First wall will be subjected to harsh conditions that will gradually deteriorate properties of the wall material. Some studies point out that fine-grained tungsten could be more resistant to the structure and property changes than coarse-grained tungsten. However, tailoring of tungsten microstructure is very laborious. Due to its high melting point, tungsten is very often processed mechanically and subsequently sintered into a compact body. In this study, preparation of ultrafine-grained tungsten by mechanical processing in a planetary ball mill was examined. Three types of tungsten samples were compared. One was made from coarse grained tungsten powder consolidated by SPS (spark plasma sintering). Other two samples were prepared from the powder processed in a planetary ball mill with and without addition of Y2O3. After ball milling, the powders were consolidated by SPS, i.e. fast sintering process that allows preserving fine-grained structure of the powder material. Properties of the samples such as hardness and thermal conductivity were examined and correlated with the processing history and microstructure.

scholarly journals Implementation of FPGA based MRPMA for high performance applications

2017 ◽  
Vol 7 (1.5) ◽  
pp. 158
Author(s):  
T. Siva Sankara Phani ◽  
M. Sujatha ◽  
K. Hari Kishore ◽  
M. Durga Prakash
Keyword(s):  
High Speed ◽  
High Performance ◽  
Finite Impulse Response ◽  
Coarse Grained ◽  
Fast Fourier Transformation ◽  
Discrete Cosine Transformation ◽  
Fine Grained ◽  
Reconfigurable Devices ◽  
Shortest Route ◽  
Domain 3

In the last few decay, Network on Chip’s (NoC) are the powerful chips for high speed communications pertaining to 802.11 Ethernet protocol which is a need to be reconfigurable for successful data frame transmission. The existing architectures like coarse grained reconfigurable, ALU cluster and expression grain reconfigurable architecture and look-up-table used in fine grained reconfigurable devices requires a lot of storage memory, hardware resources such as slices, cell area and cell delay. To tackle these issues, Multigrained Reconfiguration and Parallel Mapping Architecture (MRPMA) is proposed and their performance analysis parameters are calculated. The MRPMA uses the four contributions to optimize Processing Elements (PE’s) operations: 1) Fast Fourier Transformation (FFT) to perform fixed point numbers to the configuration words, 2) Discrete Cosine Transformation (DCT) to analyze the data in the frequency domain, 3) Finite Impulse Response (FIR) for parallel mapping the data and 4) Channel encoder and decoder to encode the data and to calculate the shortest route from source to destination switch.   

Grids, Clouds, and Massive Simulations

2014 ◽  
pp. 308-340
Author(s):  
Levente Hajdu ◽  
Jérôme Lauret ◽  
Radomir A. Mihajlović
Keyword(s):  
Cloud Computing ◽  
High Performance Computing ◽  
Nuclear Physics ◽  
High Performance ◽  
National Laboratory ◽  
Brookhaven National Laboratory ◽  
Department Of Energy ◽  
Coarse Grained ◽  
Fine Grained ◽  
Performance Computing

In this chapter, the authors discuss issues surrounding High Performance Computing (HPC)-driven science on the example of Peta science Monte Carlo experiments conducted at the Brookhaven National Laboratory (BNL), one of the US Department of Energy (DOE) High Energy and Nuclear Physics (HENP) research sites. BNL, hosting the only remaining US-based HENP experiments and apparatus, seem appropriate to study the nature of the High-Throughput Computing (HTC) hungry experiments and short historical development of the HPC technology used in such experiments. The development of parallel processors, multiprocessor systems, custom clusters, supercomputers, networked super systems, and hierarchical parallelisms are presented in an evolutionary manner. Coarse grained, rigid Grid system parallelism is contrasted by cloud computing, which is classified within this chapter as flexible and fine grained soft system parallelism. In the process of evaluating various high performance computing options, a clear distinction between high availability-bound enterprise and high scalability-bound scientific computing is made. This distinction is used to further differentiate cloud from the pre-cloud computing technologies and fit cloud computing better into the scientific HPC.

Harmonic Structure Design of Co-Cr-Mo Alloy with Outstanding Mechanical Properties

2014 ◽  
Vol 939 ◽  
pp. 60-67 ◽  
Author(s):  
Choncharoen Sawangrat ◽  
Osamu Yamaguchi ◽  
Sanjay Kumar Vajpai ◽  
Kei Ameyama
Keyword(s):  
Mechanical Properties ◽  
Mechanical Milling ◽  
Three Dimensional ◽  
High Strength ◽  
Surface Region ◽  
Structure Design ◽  
Coarse Grained ◽  
Harmonic Structure ◽  
Fine Grained ◽  
Plasma Sintering

Co-Cr-Mo alloy powders were subjected to controlled mechanical milling at room temperature under Ar atmosphere to fabricate bimodal microstructure in the MM powders, having nanosized grains in the surface region and micron-sized coarse grains in the center of the milled powders. Subsequently, the MM powder was compacted by spark-plasma sintering (SPS) process. The sintered compacts indicated two structure areas: (i) ultra-fine grained (UFG) regions, called shell, and (ii) the coarse grained regions called core. The shell and the core correspond to the surface and center of the MM powders, respectively. The shell regions established a continuous three dimensional network of high strength ultra-fine grained regions, which surrounded the discrete coarse grained ductile regions. Such a microstructure is referred as Harmonic Structure. The sintered Co-Cr-Mo alloy compacts exhibited outstanding mechanical properties. The yield strength increased from 605 to 635 MPa, and ultimate tensile strength increased from 1201 to 1283 MPa. Moreover, the elongation was maintained more or less same as that of coarse grained compacts. Therefore, the harmonic structure design leads to the new generation microstructure of Co-Cr-Mo alloy, which demonstrates outstanding mechanical properties, i.e. superior strength and excellent ductility as compared to conventional materials. Keywords: mechanical milling, Co-Cr-Mo alloys, mechanical properties, harmonic structure.

Microstructural and mechanical properties of ternary Mo-Si-B alloys resulting from different processing routes

2011 ◽  
Vol 1295 ◽  
Author(s):  
Manja Krüger ◽  
Martin Heilmaier ◽  
Veronika Shyrska ◽  
Petr I. Loboda
Keyword(s):  
Zone Melting ◽  
Coarse Grained ◽  
Processing Route ◽  
Chemical Compositions ◽  
Homogeneous Microstructure ◽  
Fine Grained ◽  
Intermetallic Matrix ◽  
Oxidation Performance ◽  
Embedded Particles ◽  
Temperature Fracture

ABSTRACTMo-base silicide alloys take advantage of their outstanding intrinsic properties, notably the high melting point and, thus, their excellent mechanical and creep strength. We demonstrate how the processing route influences the microstructure and consequently the mechanical and oxidation behaviour. Therefore two fabrication routes, a powder metallurgical (PM) and a zone melting (ZM) process, both starting from elemental powders, were used to prepare several Mo-Si-B alloys with varying chemical compositions. While PM processing leads to an ultrafine microstructure with a continuous Mo solid solution (“α-Mo”) matrix and embedded particles of the two intermetallic compounds Mo3Si and Mo5SiB2, the directionally solidified (ZM) materials possess a coarse grained structure composed of an intermetallic matrix with dendritic islands of α-Mo. A comparative assessment of the mechanical behaviour of the alloys utilizing both the Vickers indentation fracture (VIF) technique and three-point bending tests emphasizes the beneficial effect of a continuous Mo matrix resulting in increased room temperature fracture toughness and a reduction of the brittle-to-ductile-transition-temperature (BDTT). Likewise, the positive effect of the fine grained and homogeneous microstructure on oxidation performance is shown by the evaluation of mass change during heat treatment at 1100°C.

Improving Mechanical Properties of Co-Cr-W Alloys by Powder Metallurgy

2017 ◽  
Vol 890 ◽  
pp. 348-351
Author(s):  
Choncharoen Sawangrat ◽  
Komgrit Leksakul
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Total Elongation ◽  
Structure Design ◽  
Coarse Grained ◽  
Harmonic Structure ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Commercial Applications

This study focuses on improving the mechanical properties of Co-Cr-W alloys by applying Harmonic Structure Design – bimodal grain size distribution with an interconnected framework of ultra-fine-grained (UFG) regions, called the “shell region”, surrounding isolated coarse-grained (CG) regions. Harmonic structure Co-Cr specimens were successfully fabricated by Powder Metallurgy (PM) that consisted of controlled mechanical milling and spark plasma sintering. The sintered compacts revealed an outstanding combination of strength and total elongation. Moreover, the sintering dwell time significantly improved densification and led to large total elongation. PM improved the mechanical properties of Co-Cr-W alloys and offered an attractive approach to fabricate harmonic structures for commercial applications.

Correlation between dislocation, grain boundary and interface of duplex SS in stress corrosion cracking(SCC)

1990 ◽  
Vol 48 (4) ◽  
pp. 928-929
Author(s):  
Wang Zheng-fang ◽  
Z.F. Wang
Keyword(s):  
Stainless Steel ◽  
Thermal Cycle ◽  
Secondary Phase ◽  
Corrosion Cracking ◽  
Coarse Grained ◽  
Test Environment ◽  
Fine Grained ◽  
Evaluation Test ◽  
Welding Thermal Cycle ◽  
Micro Analysis

The main purpose of this study highlights on the evaluation of chloride SCC resistance of the material,duplex stainless steel,OOCr18Ni5Mo3Si2 (18-5Mo) and its welded coarse grained zone(CGZ).18-5Mo is a dual phases (A+F) stainless steel with yield strength:512N/mm2 .The proportion of secondary Phase(A phase) accounts for 30-35% of the total with fine grained and homogeneously distributed A and F phases(Fig.1).After being welded by a specific welding thermal cycle to the material,i.e. Tmax=1350°C and t8/5=20s,microstructure may change from fine grained morphology to coarse grained morphology and from homogeneously distributed of A phase to a concentration of A phase(Fig.2).Meanwhile,the proportion of A phase reduced from 35% to 5-10°o.For this reason it is known as welded coarse grained zone(CGZ).In association with difference of microstructure between base metal and welded CGZ,so chloride SCC resistance also differ from each other.Test procedures:Constant load tensile test(CLTT) were performed for recording Esce-t curve by which corrosion cracking growth can be described, tf,fractured time,can also be recorded by the test which is taken as a electrochemical behavior and mechanical property for SCC resistance evaluation. Test environment:143°C boiling 42%MgCl2 solution is used.Besides, micro analysis were conducted with light microscopy(LM),SEM,TEM,and Auger energy spectrum(AES) so as to reveal the correlation between the data generated by the CLTT results and micro analysis.

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