Role of localized heating on the workability of powder metallurgical Al–4% Ti components in cold compression

2021 ◽  
pp. 095440622110303
Author(s):  
R Tharmaraj ◽  
M Joseph Davidson ◽  
S Richard
Keyword(s):  
Grain Size ◽  
Metal Flow ◽  
Structural Components ◽  
Cold Upsetting ◽  
Damage Site ◽  
Novel Technique ◽  
Localized Heating ◽  
Powder Samples ◽  
Upsetting Test

In the present work, localised heating has been adopted at the damage site of the cold upset materials and the role of this mechanism on the workability has been analysed. Cylindrical specimens containing 96% aluminium and 4% titanium were prepared through powder metallurgy technique with an aspect ratio (height to diameter) of 1 by suitable pressures. A series of cold upsetting test was conducted and the material properties for various preforms initial relative densities (80%, 85% and 90%) were determined under the stable strain rate. The flow of metals was analysed using a finite element tool and it was observed that the metal flow starts from near the centre zone to the equatorial zone and the damage happens in the outer position because of more amount of accumulated stresses and the pores. These stresses and pores decrease the workability of the final component. Hence, the present research is intended to reduce the stresses and minimize the pores by applying a localized heating (100 °C–250 °C) at the equatorial sites of the components and thereby increasing the workability of the material. Also, heating selectively at the equatorial site of the workpiece improves the workability due to change in grain size and it was noticed that the grain size of the developed porous preforms was high for the higher heating conditions due to the growth of the grains. Therefore, the localized heating adopted in this work is a superior method to enhance the workability of the powder samples and this novel technique could be useful in improving the workability of the structural components that have extensive applications in the automobile and aerospace industries.

Evaluation of the Mechanical Properties of Carbon Nanotube (CNT) Reinforced Aluminum (6061) Composites Using Closed Die Forging

2020 ◽  
Vol 843 ◽  
pp. 33-38
Author(s):  
J.S.Suresh Babu ◽  
Jun Park ◽  
Chung Gil Kang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Compressive Strength ◽  
Large Deformations ◽  
High Energy ◽  
Cold Upsetting ◽  
Die Forging ◽  
Closed Die Forging ◽  
Energy Ball ◽  
Upsetting Test

In this study, the closed die forging of aluminium based compoistes reinfoced with CNTs (1vol% and 3vol%) were investigated. Initially, the composites were fabricated using high energy ball milling followed by compaction and sintering. The microstructural results showed that finer grain size and homogeneous dispersion of CNTs were obtained. Composites with up to 97% densification were produced when fine open porosities were removed by closed die forging. The results imply that the hardness and compressive strength of composites with 3vol.% of CNTs has improved without any deterioration. In addition, workability behaviors of composites were investigated by cold upsetting test. For that pore reopening test was performed to confirm the closure of micro-pores after the closed die forged, and to further analyze the densification of the composites. Typical cases, as the pores were not re-opened even after increasing the strain, additional forming is possible up to large deformations.

STRUCTURAL COMPONENTS OF THE PRIVATE MEDICAL SECTOR ACTIVATION MECHANISM

Economical ◽  
2019 ◽  
Vol 2 (2(21)) ◽  
pp. 170-177
Author(s):  
Anzhela Bairak ◽  
Keyword(s):  
Health Care ◽  
Health Care System ◽  
Activation Mechanism ◽  
Practical Significance ◽  
Structural Components ◽  
Medical Sector ◽  
Analysis And Synthesis ◽  
Private Medicine ◽  
Care System

The article examines the problems of private medicine in the health care system of the country. The aim of the article is to determine the structural components of the mechanism of activation of the private medical sector as a reserve for the provision of quality and affordable medical services and a driver for the development of the medical industry. The descriptive-analytical method, methods of analysis and synthesis, comparison, statistical, analysis and scientific generalization were used in the paper. The study substantiates the strengthening of the role of the private medical sector in the health care management system. The key problems of the domestic private medical sector and the restraining factors of its development are identified. It is concluded that it is necessary to develop a mechanism to promote the development of private medicine through a policy of active change in the health care system. The directions of activation of the private medical sector as a target reference point in the process of determining the structural elements of the organizational and economic mechanism are outlined. The structural detail of the mechanism of activation of the private medical sector for optimization of the health care system is offered. The practical significance of the obtained results is that the results of the research presented in the article are a practical basis for the development and improvement of mechanisms of public administration in the field of health care.

scholarly journals On the role of grain size on slurry erosion behavior of a novel medium-carbon, low-alloy pipeline steel after induction hardening

Wear ◽  
2021 ◽  
pp. 203678
Author(s):  
Vahid Javaheri ◽  
Oskari Haiko ◽  
Saeed Sadeghpour ◽  
Kati Valtonen ◽  
Jukka Kömi ◽  
...  
Keyword(s):  
Grain Size ◽  
Pipeline Steel ◽  
Induction Hardening ◽  
Slurry Erosion ◽  
Medium Carbon ◽  
Erosion Behavior

scholarly journals Magmatic Focusing to Mid-Ocean Ridges: The Role of Grain-Size Variability and Non-Newtonian Viscosity

2017 ◽  
Vol 18 (12) ◽  
pp. 4342-4355 ◽  
Author(s):  
Andrew J. Turner ◽  
Richard F. Katz ◽  
Mark D. Behn ◽  
Tobias Keller
Keyword(s):  
Grain Size ◽  
Newtonian Viscosity ◽  
Ocean Ridges ◽  
Size Variability

Role of extracellular matrix structural components and tissue mechanics in the development of postoperative pancreatic fistula

2021 ◽  
Vol 128 ◽  
pp. 110714
Author(s):  
Rosa B. Schmuck ◽  
Evi Lippens ◽  
Dag Wulsten ◽  
Daniela S. Garske ◽  
Annika Strönisch ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Pancreatic Fistula ◽  
Tissue Mechanics ◽  
Postoperative Pancreatic Fistula ◽  
Structural Components

The role of media within young people’s socialization: A theoretical approach

2019 ◽  
Vol 44 (4) ◽  
pp. 407-426
Author(s):  
Ingrid Paus-Hasebrink
Keyword(s):  
Everyday Life ◽  
Theoretical Approach ◽  
Panel Study ◽  
Social Contexts ◽  
Integrative Approach ◽  
Subjective Perception ◽  
Developmental Tasks ◽  
Structural Components ◽  
Perception Action

Abstract Researching the role of media within young people’s socialization requires an integrative approach that understands socialization as a contextual, interlinked process in which children construct their approach to life against the background of ‘developmental tasks’ and of the relevant social contexts. This article presents a praxeological approach that combines subjective and structural components of practice and that has been put into practice by means of a qualitative longitudinal-panel study on children’s socialization. The approach is based on three analytical concepts, options for action, outlines for action, and competences for action, and advances an interlinkage of subjective perception, action-driving orientations, and everyday-life practices against the backdrop of (changing) socio-structural conditions.

scholarly journals The Role of Microstructure on the Tensile Plastic Behaviour of Ductile Iron GJS 400 Produced through Different Cooling Rates—Part II: Tensile Modelling

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1019 ◽  
Author(s):  
Angella ◽  
Donnini ◽  
Ripamonti ◽  
Górny ◽  
Zanardi
Keyword(s):  
Grain Size ◽  
Ductile Iron ◽  
Volume Fraction ◽  
Interlamellar Spacing ◽  
Flow Curves ◽  
Cooling Rates ◽  
Plastic Behaviour ◽  
Microstructure Parameters ◽  
Explicit Correlation

Tensile testing on ductile iron GJS 400 with different microstructures produced through four different cooling rates was performed in order to investigate the relevance of the microstructure’s parameters on its plastic behaviour. Tensile flow curve modelling was carried out with the Follansbee and Estrin-Kocks-Mecking approach that allowed for an explicit correlation between plastic behaviour and some microstructure parameters. In the model, the ferritic grain size and volume fraction of pearlite and ferrite gathered in the first part of this investigation were used as inputs, while other parameters, like nodule count and interlamellar spacing in pearlite, were neglected. The model matched very well with the experimental flow curves at high strains, while some mismatch was found only at small strains, which was ascribed to the decohesion between the graphite nodules and the ferritic matrix that occurred just after yielding. It can be concluded that the plastic behaviour of GJS 400 depends mainly on the ferritic grain size and pearlitic volume fraction, and other microstructure parameters can be neglected, primarily because of their high nodularity and few defects.

Role of Grain Size in Strength Variability of Alumina

1994 ◽  
Vol 77 (7) ◽  
pp. 1928-1938 ◽  
Author(s):  
Desiderio Kovar ◽  
Michael J. Readey
Keyword(s):  
Grain Size ◽  
Strength Variability

scholarly journals Effect of primary silicon crystals on the fluidity of eutectic and hypereutectic Al-Si alloys in lost foam casting

2021 ◽  
Author(s):  
Shailesh Kamble
Keyword(s):  
Process Parameters ◽  
Metal Flow ◽  
Primary Silicon ◽  
Lost Foam Casting ◽  
Minor Role ◽  
Automotive Components ◽  
Silicon Crystals ◽  
A Minor ◽  
Lost Foam

The hypereutectic Aluminum-Silicon (Al-Si) Alloys are gaining impetus in the automotive components, mainly due to their wear resistance. This property in these alloys is derived from the primary silicon crystals. However, there are unique metal flow and mold filling problems associated with hypereutectic Al-Si alloys in Lost Foam Casting (LFC). This investigation is a pioneering work undertaken to gain a better understanding of the role of primary silicon crystals and other phases in the LFC of hypereutectic Al-Si alloys. Time-temperature and first derivative curves were used to determine velocity of metal flow and to calculate solid fractions. Process parameters such as superheat, gating design and alloy composition were manipulated to change the morphology of primary silicon crystals. Microscopy and image analysis of castings enabled study of precipitated particles. Solidification, interlocking and melt sluggishness of precipitated particles significantly influenced fluidity, and the routine process parameters played a minor role.

Densification Behavior in Forming of Stir Casted Aluminium Boron Carbide Composite Perform during Cold Upsetting

2014 ◽  
Vol 592-594 ◽  
pp. 117-121
Author(s):  
K.R. Thangadurai ◽  
A. Asha
Keyword(s):  
Boron Carbide ◽  
Hydrostatic Stress ◽  
Axial Stress ◽  
Testing Machine ◽  
Strain Curve ◽  
High Hardness ◽  
Casting Process ◽  
Cold Upsetting ◽  
Sem Images ◽  
Upsetting Test

The forming behavior of AA6061 boron carbide composites produced by stir casting process was investigated with the cold upsetting test. The composites containing 0%, 5%, 10% and 15% of B4Cp reinforcements were investigated with the cold upsetting test in Universal Testing Machine under tri-axial stress state condition. SEM images were taken to identify the presence of B4Cp particle in aluminium matrix. From the analysis, it was found that the hardness of composite was increased due to increasing amount of boron carbide particle in the composite and the density was decreased due to the lower value of density of boron carbide. The maximum true axial stress, true hoop stress and hydrostatic stress were gradually increased in the event of increasing order of B4Cp in the composites. Finally, it was found that in the stress – strain curve, the boron carbide was the main factor in improving the compressive strength of composites because of its high hardness.

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