scholarly journals Different Formation Routes of Pore Structure in Aluminum Powder Metallurgy Alloy

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3724 ◽  
Author(s):  
Jana Bidulská ◽  
Róbert Bidulský ◽  
Marco Actis Grande ◽  
Tibor Kvačkaj
Keyword(s):  
Plastic Deformation ◽  
Powder Metallurgy ◽  
Pore Structure ◽  
Structure Parameters ◽  
Technological Solution ◽  
Porosity Evolution ◽  
Angular Pressing ◽  
Pore Structures ◽  
Powder Metallurgy Alloy ◽  
Size And Morphology

In powder metallurgy (PM), severe plastic deformation (SPD) is a well-known technological solution to achieve interesting properties. However, the occurrence of pores in the final product may limit these properties. Also, for a given type of microstructure, the stereometric parameters of the pore structures, such as shape (represented by Aspect and Dcircle) and distribution (fshape, and fcircle), decisively affect the final properties. The influence of different processing routes (pressing, sintering and equal channel angular pressing (ECAP)) on pore structures in an aluminum PM alloy is discussed. The nature of porosity, porosity evolution and its behavior is explored. The correlation between pore size and morphology is also considered. The final pore structure parameters (Aspect, Dcircle, fshape, and fcircle) of studied aluminum alloys produced by different processing routes depends on the different formation routes.

Achieving Both Powder Consolidation and Grain Refinement for Bulk Nanostructured Materials by Equal-Channel Angular Pressing

2007 ◽  
Vol 345-346 ◽  
pp. 173-176 ◽  
Author(s):  
Seung Chae Yoon ◽  
Do Minh Nghiep ◽  
Sun Ig Hong ◽  
Z. Horita ◽  
Hyoung Seop Kim
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Powder Metallurgy ◽  
Grain Refinement ◽  
Nanostructured Materials ◽  
Equal Channel Angular Pressing ◽  
Bottom Up ◽  
Powder Consolidation ◽  
Metallic Powders ◽  
Angular Pressing

Manufacturing bulk nanostructured materials with least grain growth from initial powders is challenging because of the bottle neck of bottom-up methods using the conventional powder metallurgy of compaction and sintering. In this study, bottom-up type powder metallurgy processing and top-down type SPD (Severe Plastic Deformation) approaches were combined in order to achieve both full density and grain refinement of metallic powders. ECAP (Equal-Channel Angular Pressing), one of the most promising processes in SPD, was used for the powder consolidation method. For understanding the ECAP process, investigating the powder density as well as internal stress, strain and strain rate distribution is crucial. We investigated the consolidation and plastic deformation of the metallic powders during ECAP using the finite element simulations. Almost independent behavior of powder densification in the entry channel and shear deformation in the main deformation zone was found by the finite element method in conjunction with a pressure dependent material yield model. Effects of processing parameters on densification and density distributions were investigated.

scholarly journals The impacts of diagenetic facies on reservoir quality in tight sandstones

2020 ◽  
Vol 12 (1) ◽  
pp. 1060-1082
Author(s):  
Dazhong Ren ◽  
Liang Sun ◽  
Rongxi Li ◽  
Dengke Liu
Keyword(s):  
Pore Structure ◽  
Ordos Basin ◽  
Source Rocks ◽  
Reservoir Quality ◽  
Carbonate Content ◽  
Porosity Evolution ◽  
Carbonate Cement ◽  
Pore Structures ◽  
Diagenetic Facies ◽  
The Impact

AbstractThe impact of diagenetic minerals and the characteristics of pore structures on reservoir qualities has been studied separately in the past years. However, the difference in the reservoir quality with different pore structures and having same or similar content of diagenesis minerals has not been ascertained. In this study, based on the core samples derived from Chang 6 member in the Ordos basin, various tests were performed to examine the sandstone diagenesis and investigate the pore structure. The results showed that there were five diagenetic facies by diagenetic and pore structure analyses, and the best reservoir quality rocks were found to have relatively low percentage of illite, carbonate cement, pore-filling chlorite, authigenic quartz, and relatively high proportion of intergranular pores. Smectite-to-illite reaction and chemical compaction were main sources for quartz cementation at 60–120°C, and carbonate content was found to increase toward source rocks. The porosity depth trends significantly affected the diagenetic facies. The diagenetic and the pore structure pathways of various diagenetic facies were reconstructed by integrated petrographic, mineralogical, and pore system data. This study provides insights into the porosity evolution and diagenetic pathways of various diagenetic facies of tight sandstones, and the influence of diagenesis minerals and pore structures on their reservoir quality.

Effect of Iron Ore Tailings as Fine Aggregate on Pore Structure of Mortars

2011 ◽  
Vol 250-253 ◽  
pp. 1017-1024 ◽  
Author(s):  
Lei Yu ◽  
Jing Song Tian ◽  
Jin Xi Zhang ◽  
Rong Jun Yang
Keyword(s):  
Pore Structure ◽  
Iron Ore ◽  
Fine Aggregate ◽  
Structure Parameters ◽  
Cement Concrete ◽  
Natural Sand ◽  
Iron Ore Tailings ◽  
Pore Structures ◽  
Fine Aggregates

Effect of iron ore tailings as fine aggregate on pore structure of mortars has been studied in this paper. The purpose is to investigate, as fine aggregate, comparing to natural sand, whether the iron ore tailings can improve the pore structures of mortars or not. Pore structure parameters were measured with the instrument of MIP and calculated with corollary software. The pore structure parameters from four kinds of mortars with different fine aggregates are compared with each other. This paper will provide more data about the use of this artificial aggregate, which may increase the feasibility of the use of this by-product in the mortar or cement concrete industry.

TECHNOLOGIES FOR MANUFACTURING NANOSTRUCTURED SURFACES

2020 ◽  
Author(s):  
Андрей Дмитриевич Бухтеев ◽  
Виктория Буянтуевна Бальжиева ◽  
Анна Романовна Тарасова ◽  
Фидан Гасанова ◽  
Светлана Викторовна Агасиева
Keyword(s):  
Plastic Deformation ◽  
Surface Modification ◽  
Severe Plastic Deformation ◽  
Pressing Pressure ◽  
Pressure Treatment ◽  
Structured Surfaces ◽  
Nanostructured Surfaces ◽  
Angular Pressing ◽  
Multilayer Composites ◽  
Compaction Of Powders

В данной статье рассматривается применение и технологии получения наноструктурированных поверхностей. Рассмотрены такие методы как компактирование порошков (изостатическое прессование, метод Гляйтера), интенсивная пластическая деформация (угловое кручение, равноканальное угловое прессование, обработка давлением многослойных композитов) и модификация поверхности (лазерная обработка, ионная бомбардировка). This article discusses the application and technology for obtaining nano-structured surfaces. Methods such as compaction of powders (isostatic pressing, Gleiter method), severe plastic deformation (angular torsion, equal-channel angular pressing, pressure treatment of multilayer composites) and surface modification (laser treatment, ion bombardment) are considered.

On development of hypoeutectic aluminium–silicon powder metallurgy alloy

2011 ◽  
Vol 54 (3) ◽  
pp. 432-439 ◽  
Author(s):  
W G Mosher ◽  
G J Kipouros ◽  
W F Caley ◽  
I W Donaldson ◽  
D P Bishop
Keyword(s):  
Powder Metallurgy ◽  
Silicon Powder ◽  
Powder Metallurgy Alloy

scholarly journals Deformation of Ordered Mesoporous Silica Structures on Exposure to High Temperatures

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
John B. Lowe ◽  
Richard T. Baker
Keyword(s):  
Mesoporous Silica ◽  
Pore Structure ◽  
High Temperatures ◽  
Elevated Temperatures ◽  
Ordered Mesoporous Silica ◽  
Large Cage ◽  
Pore Structures ◽  
Ordered Mesoporous ◽  
Pore Size Distributions ◽  
Wide Range

Ordered mesoporous silica materials are of interest for a wide range of applications. In many of these, elevated temperatures are used either in the preparation of the material or during its use. Therefore, an understanding of the effect of high temperature treatments on these materials is desirable. In this work, a detailed structural study is performed on silicas with three representative pore structures: a 2-D hexagonal pore arrangement (SBA-15), a continuous 3D cubic bimodal pore structure (KIT-6), and a 3D large cage pore structure (FDU-12). Each silica is studied as prepared and after treatment at a series of temperatures between 300 and 900°C. Pore structures are imaged using Transmission Electron Microscopy. This technique is used in conjunction with Small-Angle X-ray Diffraction, gas physisorption, and29Si solid state Nuclear Magnetic Resonance. Using these techniques, the pore size distributions, the unit cell dimensions of the mesoporous structures, and the relative occupancy of the distinct chemical environments of Si within them are cross correlated for the three silicas and their evolution with treatment temperature is elucidated. The physical and chemical properties before, during, and after collapse of these structures at high temperatures are described as are the differences in behavior between the three silica structures.

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