scholarly journals Microstructural Characterization of Beryllium Treated Al-Si Alloys

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
M. F. Ibrahim ◽  
S. A. Alkahtani ◽  
Kh. A. Abuhasel ◽  
F. H. Samuel
Keyword(s):  
Mechanical Properties ◽  
Fine Particles ◽  
Eutectic Temperature ◽  
Microstructural Characterization ◽  
Noticeable Effect ◽  
Thermal Analysis Technique ◽  
Analysis Technique ◽  
Eutectic Si ◽  
Harmful Effects

The present study was carried out on B356 and B357 alloys using the thermal analysis technique. Metallographic samples prepared from these castings were examined using optical microscopy and FESEM. Results revealed that beryllium causes partial modification of the eutectic Si, similar to that reported for magnesium additions. Addition of 0.8 wt.% Mg reduces the eutectic temperature by ~10°C. During solidification of alloys containing high levels of Fe and Mg, but no Sr, formation of a Be-Fe phase was detected at 611°C, close to that ofα-Al. The Be-Fe phase precipitates in script-like form at or close to theβ-Al5SiFe platelets. A new reaction, composed of fine particles of Si andπ-Fe phase, was observed to occur near the end of solidification in high Mg-, high Fe-, and Be-containing alloys. The amount of this reaction decreased with the addition of Sr. Occasionally, Be-containing phase particles were observed as part of the reaction. Addition of Be has a noticeable effect on decreasing theβ-Al5FeSi platelet length; this effect may be enhanced by addition of Sr. Beryllium addition also results in precipitation of theβ-Al5FeSi phase in nodular form, which lowers its harmful effects on the alloy mechanical properties.

scholarly journals Effect of Rare Earth Metals, Sr, and Ti Addition on the Microstructural Characterization of A413.1 Alloy

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
M. G. Mahmoud ◽  
A. M. Samuel ◽  
H. W. Doty ◽  
S. Valtierra ◽  
F. H. Samuel
Keyword(s):  
Rare Earth ◽  
Eutectic Temperature ◽  
Rare Earth Metals ◽  
Microstructural Characterization ◽  
Second Phase ◽  
White Phase ◽  
Eutectic Si ◽  
Ti Addition ◽  
Grey Phase

The present work was performed on A413.1 alloy containing 0.2–1.5 wt% rare earth metals (lanthanum or cerium), 0.05–0.15% Ti, and 0–0.02 wt% Sr. These elements were either added individually or combined. Thermal analysis, image analysis, and electron probe microanalysis were the main techniques employed in the present study. The results show that the use of the depression in the eutectic temperature as a function of alloy modification cannot be applied in the case when the alloy is treated with rare earth metals. Increasing the concentration of RE increases the solidification zone especially in Sr-modified alloys leading to poor feeding ability. This observation is more prominent in the case of Ce addition. Depending upon the amount of added Ti, two RE based intermetallics can be formed: (i) a white phase, mainly platelet-like (approximately 2.5 μm thick), that is rich in RE, Si, Cu, and Al and (ii) a second phase made up of mainly grey sludge particles (star-like) branching in different directions. The grey phase is rich in Ti with some RE (almost 20% of that in the white phase) with traces of Si and Cu. There is a strong interaction between RE and Sr leading to a reduction in the efficiency of Sr as a eutectic Si modifier causing particle demodification.

Effect of Titanium on Microstructure and Solidification Behavior of Gray Irons

2020 ◽  
Vol 987 ◽  
pp. 177-181
Author(s):  
Sarum Boonmee ◽  
Kittirat Worakhut ◽  
Preecha Maneelum
Keyword(s):  
Thermal Analysis ◽  
Fine Particles ◽  
Eutectic Mixture ◽  
Solidification Behavior ◽  
Titanium Addition ◽  
Thermal Analysis Technique ◽  
Graphite Particles ◽  
Analysis Technique ◽  
Eutectic Undercooling ◽  
Ti Addition

This study investigates the microstructure and the solidification behavior of titanium-alloyed gray irons. Thermal analysis technique was used to identify the Temperature of Liquidus Arrest (TLA), the Temperature of Eutectic Undercooling (TEU) and the Temperature of the Eutectic Recalescence (TER). It was found that the titanium addition promoted the formation of the primary austenite causing the larger difference in TLA and TEU. In addition, titanium encouraged the refining of eutectic mixture. The SEM showed the graphite particles were refined with increasing titanium. Fine particles of titanium-containing compound were readily observed throughout the microstructure. The hardness as high as 176 HB was achieved at 0.495%Ti addition.

Mechanical properties and microstructural characterization of selective laser melted 17-4 PH stainless steel

2017 ◽  
Vol 23 (2) ◽  
pp. 280-294 ◽  
Author(s):  
Mohamad Mahmoudi ◽  
Alaa Elwany ◽  
Aref Yadollahi ◽  
Scott M. Thompson ◽  
Linkan Bian ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Microstructural Characterization

Effect of Microalloying Elements on Mechanical Properties in the High Strength Low Alloy Steel

2015 ◽  
Vol 830-831 ◽  
pp. 231-233 ◽  
Author(s):  
P.K. Mandal ◽  
Ravi Kant
Keyword(s):  
Mechanical Properties ◽  
Hsla Steel ◽  
High Strength ◽  
Microstructural Characterization ◽  
Strengthening Mechanism ◽  
Treatment Processes ◽  
Heating Treatment ◽  
Secondary Precipitates ◽  
Microalloying Elements

The effect of microalloying elements in Ti-Nb-V containing high strength low alloy (HSLA) steel has been investigated in the present study. The addition of low alloying elements (such as Ti, Nb and V) and distinct heating treatment processes has been used to improve the mechanical properties of HSLA steel. The effect on the microstructure and mechanical properties of normalizing treatment (at 950°C) of as forged steel has been investigated. The microstructural characterization of microalloyed HSLA steel is carried out by using different techniques such as optical microscopy, scanning electron microscopy (SEM) etc. The hardness, tensile testing and Charpy V notch impact tests are performed to study the mechanical behaviour of the alloy. It has been concluded that the precipitation strengthening mechanism for the improvement of impact toughness due to secondary precipitates such as TiN, Ti(C, N), VN etc.

Mechanical and Microstructural Characterization of Al-6082 Ultrafine-Grained Alloys Processed by ECAP Combined with Traditional Forming Techniques

2008 ◽  
Vol 589 ◽  
pp. 111-116 ◽  
Author(s):  
György Krállics ◽  
Arpad Fodor ◽  
Jenő Gubicza ◽  
Z. Fogarassy
Keyword(s):  
Mechanical Properties ◽  
Equal Channel Angular Pressing ◽  
Microstructural Characterization ◽  
Shape Rolling ◽  
Rotary Forging ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Forming Methods

An Al-6082 alloy was subjected to equal channel angular pressing (ECAP) and subsequently to conventional forming methods such as shape rolling and rotary forging. The effect of different deformation techniques on the microstructure and the mechanical properties was studied. It was found that the shape rolling and rotary forging increased further the strength of ECAP-processed samples and induced a loss of ductility.

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