scholarly journals The mutual effect of iron and manganese on microstructure and mechanical properties of aluminium –silicon alloy

10.30544/383 ◽  
2010 ◽  
Vol 16 (1) ◽  
pp. 11-24 ◽  
Author(s):  
Alireza Darvishi ◽  
Ali Maleki ◽  
Mehdi Mazar Atabaki ◽  
Mohammad Zargami
Keyword(s):  
Mechanical Properties ◽  
Intermetallic Compounds ◽  
Volume Fraction ◽  
Manganese Content ◽  
Mutual Effect ◽  
Manganese Concentration ◽  
Microstructural Investigation ◽  
High Concentrations ◽  
Different Content ◽  
Iron And Manganese

The effect of iron and manganese concentration on the morphology of complex intermetallics and their influence on the mechanical properties and microstructure has been studied in an Al-16.67 wt. % Si alloy with three content of iron (0.4, 1.2, 1.8 wt.%), and two different content of manganese, i.e. 0.6 and 0.9 wt.%. The intermetallic compounds are formed at high iron contents or at high concentrations of manganese with low iron. The microstructural investigation by Clemex software showed that the biggest intermetallic size reached the surface area of 12750 μm2, when the amount of iron was increased from 1.2% to 1.8% wt.%. It was also showed that the volume fraction of intermetallic compounds increases as the iron and manganese content increases. Formation of complex intermetallic phases with iron adversely affects tensile strength decreasing from 229MPa with 0.4 wt.% of iron to 187MPa when iron content was increased to 1.8 wt.%.

MICROSTRUCTURE AND MECHANICAL BEHAVIOR OF AMORPHOUS Al–Cu–Ti METAL FOAMS SYNTHESIZED BY SPARK PLASMA SINTERING

2017 ◽  
Vol 24 (Supp02) ◽  
pp. 1850022
Author(s):  
MAOYUAN LI ◽  
LIN LU ◽  
ZHEN DAI ◽  
YIQIANG HONG ◽  
WEIWEI CHEN ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Intermetallic Compounds ◽  
Spark Plasma Sintering ◽  
Elevated Temperatures ◽  
Volume Fraction ◽  
Metal Foams ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Xrd Patterns

Amorphous Al–Cu–Ti metal foams were prepared by spark plasma sintering (SPS) process with the diameter of 10[Formula: see text]mm. The SPS process was conducted at the pressure of 200 and 300[Formula: see text]MPa with the temperature of 653–723[Formula: see text]K, respectively. NaCl was used as the space-holder, forming almost separated pores with the porosity of 65 vol%. The microstructure and mechanical behavior of the amorphous Al–Cu–Ti metal foams were systematically investigated. The results show that the crystallinity increased at elevated temperatures. The effect of pressure and holding time on the crystallization was almost negligible. The intermetallic compounds, i.e. Al–Ti, Al–Cu and Al–Cu–Ti were identified from X-ray diffraction (XRD) patterns. It was found that weak adhesion and brittle intermetallic compounds reduced the mechanical properties, while lower volume fraction and smaller size of NaCl powders improved the mechanical properties.

scholarly journals Structural and Mechanical Properties of Amorphous Si3N4 Nanoparticles Reinforced Al Matrix Composites Prepared by Microwave Sintering

Ceramics ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 126-134 ◽  
Author(s):  
Manohar Mattli ◽  
Penchal Matli ◽  
Abdul Shakoor ◽  
Adel Amer Mohamed
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Yield Strength ◽  
Volume Fraction ◽  
Microwave Sintering ◽  
Aluminum Matrix ◽  
Microstructural Investigation ◽  
Porosity Level ◽  
Amorphous Si3n4 ◽  
Al Matrix

The present study focuses on the synthesis and characterization of amorphous silicon nitride (Si3N4) reinforced aluminum matrix nanocomposites through the microwave sintering process. The effect of Si3N4 (0, 1, 2 and 3 wt.%) nanoparticles addition to the microstructure and mechanical properties of the Al-Si3N4 nanocomposites were investigated. The density of Al-Si3N4 nanocomposites increased with increased Si3N4 content, while porosity decreased. X-ray diffraction (XRD) analysis reveals the presence of Si3N4 nanoparticles in Al matrix. Microstructural investigation of the nanocomposites shows the uniform distribution of Si3N4 nanoparticles in the aluminum matrix. Mechanical properties of the composites were found to increase with an increasing volume fraction of amorphous Si3N4 reinforcement particles. Al-Si3N4 nanocomposites exhibits higher hardness, yield strength and enhanced compressive performance than the pure Al matrix. A maximum increase of approximately 72% and 37% in ultimate compressive strength and 0.2% yield strength are achieved. Among the synthesized nanocomposites, Al-3wt.% Si3N4 nanocomposites displayed the maximum hardness (77 ± 2 Hv) and compressive strength (364 ± 2 MPa) with minimum porosity level of 1.1%.

scholarly journals Phase transformations during the crystallization of the AK7 alloy, neutralization of the harmful effect of iron by treating the melt with a pulsed electric current

2020 ◽  
Vol 96 (4) ◽  
pp. 17-29
Author(s):  
A.G. Prigunova ◽  
Keyword(s):  
Mechanical Properties ◽  
Phase Transformations ◽  
Electric Current ◽  
Intermetallic Compounds ◽  
Volume Fraction ◽  
Cluster Structure ◽  
Harmful Effect ◽  
Study Phase ◽  
Current Frequency ◽  
Pulsed Electric Current

The method of quenching-microstructural analysis, the so-called "stop-quenching", was used to study phase transformations during crystallization of the AK7 casting alloy of the Al-Si-Mg system. The alloy is smelted from scrap and waste, therefore it contains a large amount of impurities, including iron, copper. It was found that the formation of the structure of the AK7 alloy is carried out in the course of the following reactions: 1. Р → Аlα. 2. P → α-(Fe, Mn) 3Si2Al15 + Alα. 3. P → β-FeSiAl5 + Alα. 4. P + β-FeSiAl5 → α-(Fe, Mn, Cu)3Si2Al15. 5. P → β-FeSiAl5 + Si + Alα. 6. P → β-FeSiAl5 + α-(Fe, Mn, Cu)3Si2Al15 + Si + Alα. At the last stages of crystallization, eutectics are formed, which include phases with magnesium and copper: Mg2Si, π-FeMg3Si6Al8, W-Cu2Mg8Si6Al and θ-CuAl2. The transformation P → β + Si + Alα is realized both by the mechanism of cooperative growth of the β, Si, and Alα phases, and by the formation of double eutectics: P → Si + Alα and P → β + Alα, which grow simultaneously in the same temperature range from various centers of crystallization. The four-phase eutectic transformation P → β + α + Si + Alα is carried out according to the type of double or triple eutectic reactions: P → Si + Alα; P → α + Alα; P → β + Alα; β + Si + Alα. The main iron-containing phase in the AK7 alloy is the needle-shaped intermetallic compound β-FeSiAl5 - a stress concentrator, which leads to a decrease in mechanical properties. In this work, the neutralization of the harmful effect of iron was carried out by treating the melt with a unipolar pulsed electric current, under the influence of which the cluster structure of the melt changes. During crystallization, instead of β, a branched phase α is formed. The ratio of intermetallic compounds β and α depends on the processing modes. With optimal parameters of density and current frequency, at which the volume fraction of the branched phase α is the largest, the strength of the AK7 alloy increases by 32.1%, the hardness by 16.7%, and the relative elongation by 2.5 times, bringing its mechanical properties closer to the primary alloy AK7h. Keywords: aluminum-silicon alloys, phase transformations, iron-containing intermetallic compounds, growth forms, treatment of the melt with an electric current.

scholarly journals Manganese Removal from Liquid Nickel by Hydrogen Plasma Arc Melting

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 33
Author(s):  
Xiliang Guo ◽  
Jianbo Yu ◽  
Yuan Hou ◽  
Yujia Zhang ◽  
Jiang Wang ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Hydrogen Plasma ◽  
Manganese Content ◽  
Manganese Concentration ◽  
Slight Reduction ◽  
Plasma Arc ◽  
Liquid Nickel ◽  
Hydrogen Atoms ◽  
Manganese Removal ◽  
Arc Melting

In this work, the removal of manganese from nickel melts by Ar and (10%, 20% and 40%) H2 plasma arc melting under various pressures (0.01–0.02, 0.04–0.05 and 0.09–0.1 MPa) was investigated experimentally. The results show that only a slight reduction in the manganese content is obtained by Ar plasma arc melting (PAM). By contrast, the manganese content of liquid nickel decreases noticeably upon the addition of hydrogen to plasma gas, and the rate of manganese removal increases with increasing hydrogen volume fraction. In addition, the reduction in the pressure enhances the efficiency of manganese removal from liquid nickel by hydrogen plasma arc melting (HPAM). The process of manganese removal by HPAM was found to obey a first-order rate law. From kinetic analysis, the rate of reduction in the manganese content increases proportionally to the 0.73–0.75th power of the hydrogen volume fraction in the plasma gas. However, the rate of the manganese content reduction increases proportionally to approximately 0.88th power of %H2 in the plasma gas for the initial manganese content of 0.89 mass%, which is slightly higher than that for the initial manganese concentration of 0.45 mass%. Thermodynamic analysis indicates that the volatilization of manganese benefits from negative pressure and the presence of active hydrogen atoms that act as the transfer media of the metal vapor in the gas boundary layer.

Macroprobe Mode for the Study of Segregation in Steels

1990 ◽  
Vol 48 (2) ◽  
pp. 260-261
Author(s):  
Auclair Gilles ◽  
Benoit Danièle
Keyword(s):  
Mechanical Properties ◽  
Spatial Distribution ◽  
High Performance ◽  
Volume Fraction ◽  
Sheet Steel ◽  
Acquisition Time ◽  
Chemical Information ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Optical Micrographs

During these last 10 years, high performance correction procedures have been developed for classical EPMA, and it is nowadays possible to obtain accurate quantitative analysis even for soft X-ray radiations. It is also possible to perform EPMA by adapting this accurate quantitative procedures to unusual applications such as the measurement of the segregation on wide areas in as-cast and sheet steel products.The main objection for analysis of segregation in steel by means of a line-scan mode is that it requires a very heavy sampling plan to make sure that the most significant points are analyzed. Moreover only local chemical information is obtained whereas mechanical properties are also dependant on the volume fraction and the spatial distribution of highly segregated zones. For these reasons we have chosen to systematically acquire X-ray calibrated mappings which give pictures similar to optical micrographs. Although mapping requires lengthy acquisition time there is a corresponding increase in the information given by image anlysis.

A Study of Some Mechanical and Physical Properties for Palm Fiber/Polyester Composite

2020 ◽  
Vol 38 (3B) ◽  
pp. 104-114
Author(s):  
Samah M. Hussein
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Dielectric Constant ◽  
Date Palm ◽  
Volume Fraction ◽  
Unsaturated Polyester ◽  
Dielectric Strength ◽  
Palm Fiber ◽  
Mechanical And Physical Properties ◽  
Polyester Composite

This research has been done by reinforcing the matrix (unsaturated polyester) resin with natural material (date palm fiber (DPF)). The fibers were exposure to alkali treatment before reinforcement. The samples have been prepared by using hand lay-up technique with fiber volume fraction of (10%, 20% and 30%). After preparation of the mechanical and physical properties have been studied such as, compression, flexural, impact strength, thermal conductivity, Dielectric constant and dielectric strength. The polyester composite reinforced with date palm fiber at volume fraction (10% and 20%) has good mechanical properties rather than pure unsaturated polyester material, while the composite reinforced with 30% Vf present poor mechanical properties. Thermal conductivity results indicated insulator composite behavior. The effect of present fiber polar group induces of decreasing in dielectric strength, and increasing dielectric constant. The reinforcement composite 20% Vf showed the best results in mechanical, thermal and electrical properties.

Effect of Titanium Carbide Particles on Mechanical Properties of Aluminum Matrix Composites

2017 ◽  
Vol 5 (2) ◽  
pp. 20-30
Author(s):  
Zaman Khalil Ibrahim
Keyword(s):  
Mechanical Properties ◽  
Titanium Carbide ◽  
Compression Strength ◽  
Volume Fraction ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Powder Metallurgy Technique ◽  
Carbide Particles ◽  
Properties Of Composites

In this research aluminum matrix composites (AMCs) was reinforced by titanium carbide (TiC) particles and was produced. Powder metallurgy technique (PM) has been used to fabricate AMCs reinforced with various amounts (0%, 4%, 8%, 12%, 16% and 20% volume fraction) of TiC particles to study the effect of different volume fractions on mechanical properties of the Al-TiC composites. Measurements of compression strength and hardness showed that mechanical properties of composites increased with an increase in volume fraction of TiC Particles. Al-20 % vol. TiC composites exhibited the best properties with hardness value (97HRB) and compression strength value (275Mpa).

ETERMINATION IRON AND MANGANESE CONTENT IN MOTOR FUELS

2017 ◽  
Vol 59 (2) ◽  
pp. 097-102
Author(s):  
Anastasiya A. Kotlova ◽  
◽  
Ilya A. Belous ◽  
Anastasiya V. Kiyashko ◽  
Roman S. Edigarev ◽  
...  
Keyword(s):  
Manganese Content ◽  
Motor Fuels ◽  
Iron And Manganese

Monitoring of mechanical properties of prestressed glass fiber epoxy composites over 12 months after fabrication

2021 ◽  
pp. 002199832110047
Author(s):  
Mahmoud Mohamed ◽  
Siddhartha Brahma ◽  
Haibin Ning ◽  
Selvum Pillay
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Flexural Strength ◽  
Compressive Residual Stress ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Epoxy Composites ◽  
Flexural Properties ◽  
Initial Increase ◽  
Fiber Volume

Fiber prestressing during matrix curing can significantly improve the mechanical properties of fiber-reinforced polymer composites. One primary reason behind this improvement is the generated compressive residual stress within the cured matrix, which impedes cracks initiation and propagation. However, the prestressing force might diminish progressively with time due to the creep of the compressed matrix and the relaxation of the tensioned fiber. As a result, the initial compressive residual stress and the acquired improvement in mechanical properties are prone to decline over time. Therefore, it is necessary to evaluate the mechanical properties of the prestressed composites as time proceeds. This study monitors the change in the tensile and flexural properties of unidirectional prestressed glass fiber reinforced epoxy composites over a period of 12 months after manufacturing. The composites were prepared using three different fiber volume fractions 25%, 30%, and 40%. The results of mechanical testing showed that the prestressed composites acquired an initial increase up to 29% in the tensile properties and up to 32% in the flexural properties compared to the non-prestressed counterparts. Throughout the 12 months of study, the initial increase in both tensile and flexural strength showed a progressive reduction. The loss ratio of the initial increase was observed to be inversely proportional to the fiber volume fraction. For the prestressed composites fabricated with 25%, 30%, and 40% fiber volume fraction, the initial increase in tensile and flexural strength dropped by 29%, 25%, and 17%, respectively and by 34%, 26%, and 21%, respectively at the end of the study. Approximately 50% of the total loss took place over the first month after the manufacture, while after the sixth month, the reduction in mechanical properties became insignificant. Tensile modulus started to show a very slight reduction after the fourth/sixth month, while the flexural modulus reduction was observed from the beginning. Although the prestressed composites displayed time-dependent losses, their long-term mechanical properties still outperformed the non-prestressed counterparts.

scholarly journals Heat Treatment Evaluation for the Camshafts Production of ADI Low Alloyed with Vanadium

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1036
Author(s):  
Eduardo Colin García ◽  
Alejandro Cruz Ramírez ◽  
Guillermo Reyes Castellanos ◽  
José Federico Chávez Alcalá ◽  
Jaime Téllez Ramírez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ductile Iron ◽  
Volume Fraction ◽  
Energy Impact ◽  
Treatment Conditions ◽  
Mold Casting ◽  
Grade 3 ◽  
Good Agreement

Ductile iron camshafts low alloyed with 0.2 and 0.3 wt % vanadium were produced by one of the largest manufacturers of the ductile iron camshafts in México “ARBOMEX S.A de C.V” by a phenolic urethane no-bake sand mold casting method. During functioning, camshafts are subject to bending and torsional stresses, and the lobe surfaces are highly loaded. Thus, high toughness and wear resistance are essential for this component. In this work, two austempering ductile iron heat treatments were evaluated to increase the mechanical properties of tensile strength, hardness, and toughness of the ductile iron camshaft low alloyed with vanadium. The austempering process was held at 265 and 305 °C and austempering times of 30, 60, 90, and 120 min. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by XRD measurements. The ausferritic matrix was determined in 90 min for both austempering temperatures, having a good agreement with the microstructural and hardness evolution as the austempering time increased. The mechanical properties of tensile strength, hardness, and toughness were evaluated from samples obtained from the camshaft and the standard Keel block. The highest mechanical properties were obtained for the austempering heat treatment of 265 °C for 90 min for the ADI containing 0.3 wt % V. The tensile and yield strength were 1200 and 1051 MPa, respectively, while the hardness and the energy impact values were of 47 HRC and 26 J; these values are in the range expected for an ADI grade 3.

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