scholarly journals Effect of Eutectic Mg2Si Phase Modification on the Mechanical Properties of Al-8Zn-6Si-4Mg-2Cu Cast Alloy

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 32 ◽  
Author(s):  
Byung Joo Kim ◽  
Sung Su Jung ◽  
Ji Hoon Hwang ◽  
Yong Ho Park ◽  
Young Cheol Lee
Keyword(s):  
Mechanical Properties ◽  
Master Alloy ◽  
Base Alloy ◽  
Cast Alloy ◽  
Energy Dispersive Spectrometer ◽  
Chinese Script ◽  
Phase Modification ◽  
Master Alloys ◽  
Polygonal Shape ◽  
Tib2 Particles

The modification effect of Al-5Ti-1B master alloy on eutectic Mg2Si in Al-Zn-Si-Mg system alloy was investigated in this study. The microstructure shows that an extreme effect can be achieved after the addition of Al-5Ti-1B master alloy into the base alloy. The morphology of eutectic Mg2Si changed from Chinese script to fine polygonal shape, and the size was refined from over 50 μm to under 10 μm. This morphology change is believed to be due to TiB2 particles existing in Al-5Ti-1B master alloy, and the presence of TiB2 particles inside the modified Mg2Si was confirmed by scanning electron microscope/energy dispersive spectrometer (SEM/EDS) observation. The mechanical properties were also improved by the addition of Al-5Ti-1B master alloys. This study investigated the reason for the improvement in mechanical properties with the modification of the microstructure.

The influence of gadolinium on Al–Ti–C master alloy and its refining effect on AZ31 magnesium alloy

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wenxue Fan ◽  
Hai Hao
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Magnesium Alloys ◽  
Master Alloy ◽  
Cast Alloy ◽  
Az31 Magnesium Alloy ◽  
Synthesis Mechanism ◽  
Refining Effect ◽  
Master Alloys

Abstract Grain refinement has a significant influence on the improvement of mechanical properties of magnesium alloys. In this study, a series of Al–Ti–C-xGd (x = 0, 1, 2, 3) master alloys as grain refiners were prepared by self-propagating high-temperature synthesis. The synthesis mechanism of the Al–Ti–C-xGd master alloy was analyzed. The effects of Al–Ti–C-xGd master alloys on the grain refinement and mechanical properties of AZ31 (Mg-3Al-1Zn-0.4Mn) magnesium alloys were investigated. The results show that the microstructure of the Al–Ti–C-xGd alloy contains α-Al, TiAl3, TiC and the core–shell structure TiAl3/Ti2Al20Gd. The refining effect of the prepared Al–Ti–C–Gd master alloy is obviously better than that of Al–Ti–C master alloy. The grain size of AZ31 magnesium alloy was reduced from 323 μm to 72 μm when adding 1 wt.% Al–Ti–C-2Gd master alloy. In the same condition, the ultimate tensile strength and elongation of as-cast alloy were increased from 130 MPa, 7.9% to 207 MPa, 16.6% respectively.

scholarly journals The Mechanical Properties of AlSi17Cu5 Cast Alloy after Overheating and Modification of CuP Master Alloy

2013 ◽  
Vol 13 (3) ◽  
pp. 68-71
Author(s):  
J. Piątkowski ◽  
M. Jabłońska
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Master Alloy ◽  
Liquid State ◽  
Alloy Composition ◽  
Cast Alloy ◽  
Primary Silicon ◽  
Grain Structure ◽  
Silicon Crystals ◽  
Fine Grain

Abstract The paper presents the results of studies on the effect of the AlSi17Cu5 alloy overheating to atemperature of 920°C and modification with phosphorus (CuP10) on the resultingmechanical (HB, Rm, R0.2) and plastic (A5 and Z) properties. It has been shown that, so-called, "timethermal treatment" (TTT) of an alloy in the liquid state, consisting inoverheating the metal to about 250°C above Tliq,holding at this temperature by 30 minutes improvesthe mechanical properties. It has also been found that overheating of alloy above Tliq.enhances the process of modification, resulting in the formation of fine-grain structure. The primary silicon crystals uniformly distributed in the eutectic and characteristics ofthe α(Al) solution supersaturated with alloying elements present in the starting alloy composition (Cu, Fe) provide not only an increase of strength at ambient temperature but also at elevated temperature (250°C).

Effect of Sr and Sb on Microstructure and Mechanical Properties of Mg-5AI-2Si Alloys

2006 ◽  
Vol 321-323 ◽  
pp. 1365-1369 ◽  
Author(s):  
Dae Hyun Song ◽  
C.W. Lee ◽  
K.Y. Nam ◽  
S.W. Lee ◽  
Yong Ho Park ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Creep Resistance ◽  
Tensile Elongation ◽  
Chinese Script ◽  
Microstructure And Mechanical Properties ◽  
Polygonal Shape

A study has been made on the effects of antimony (Sb) and strontium (Sr) additions on the microstructure of Mg-Al-Si alloys. Results showed that the additions of Sb and Sr can modify the morphology of Mg2Si particles from Chinese script shape to refined polygonal shape. Tensile strength and creep resistance were improved and tensile elongation was also increased in the modified alloy with Sb and Sr. The addition of Sr was more effective than Sb modification of AS52 alloy for refining microstructure and thus improving properties.

scholarly journals Alloyed White Cast Iron with Precipitates of Spheroidal Vanadium Carbides VC

2012 ◽  
Vol 12 (4) ◽  
pp. 95-100 ◽  
Author(s):  
M. Kawalec ◽  
M. Górny
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Cast Iron ◽  
Master Alloy ◽  
Eutectic Composition ◽  
White Cast Iron ◽  
Base Alloy ◽  
Cast Steel ◽  
Abrasive Wear Resistance ◽  
Vanadium Carbides

Abstract The paper presents the results of tests on the spheroidising treatment of vanadium carbides VC done with magnesium master alloy and mischmetal. It has been proved that the introduction of magnesium master alloy to an Fe-C-V system of eutectic composition made 34% of carbides crystallise in the form of spheroids. Adding mischmetal to the base alloy melt caused 28% of the vanadium carbides crystallise as dendrites. In base alloy without the microstructure-modifying additives, vanadium carbides crystallised in the form of a branched fibrous eutectic skeleton. Testing of mechanical properties has proved that the spheroidising treatment of VC carbides in high-vanadium cast iron increases the tensile strength by about 60% and elongation 14 - 21 times, depending on the type of the spheroidising agent used. Tribological studies have shown that high-vanadium cast iron with eutectic, dendritic and spheroidal carbides has the abrasive wear resistance more than twice as high as the abrasion-resistant cast steel.

Temperature Effect of Refining Performance by Al-Ti-B (C) Master Alloys

2011 ◽  
Vol 306-307 ◽  
pp. 475-480
Author(s):  
Cong Juan Gao ◽  
Hai Min Ding ◽  
Xiang Fa Liu
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Temperature Effect ◽  
Master Alloy ◽  
Experimental Results ◽  
Refining Effect ◽  
Master Alloys ◽  
Refining Performance ◽  
Tib2 Particles ◽  
Performance And Mechanism

Refining performance and mechanism of Al-5Ti-1B and Al-5Ti-0.4C master alloys at different temperature were investigated in this paper. The experimental results show that the refining effect of Al-5Ti-0.4C master alloy becomes worse as temperature increasing from 750°C to 1200°C, The refining effect of Al-5Ti-1B master alloy becomes worse as temperature increasing from 750°C to 1000°C. However, when the temperature is above 1000°C, the refining effect of Al-5Ti-1B master alloy recovers gradually as temperature increasing. TiB2 particles with TiAl3 layers are the heterogeneous nucleating cores of α-Al at low temperature. However, TiB2 particles are the heterogeneous nuclei of α-Al at high temperature.

Grain Refinement of Zn-50Al Alloy through the Addition of Zn–Al-Ti-B-C Master Alloy and Melt Thermal-Rate Treatment

2012 ◽  
Vol 562-564 ◽  
pp. 238-241
Author(s):  
Z.Q Wang ◽  
D.L Yang ◽  
Z.X Yang ◽  
H.R Geng
Keyword(s):  
Grain Refinement ◽  
Master Alloy ◽  
Treatment Process ◽  
Step Method ◽  
Master Alloys ◽  
The Matrix ◽  
Tib2 Particles ◽  
Refinement Effect ◽  
Al Matrix

In this paper, two types of Zn-Al-Ti-B-C master alloys were produced by a two-step method and were found to have good refinement effect for Zn-50Al alloy. SEM results show that TiC and TiB2 particles act as the nucleating center of α-Al grains in Zn-50Al alloy. The presence of TiAl3-xZnx phase in the matrix of Zn-Al-Ti-B-C master alloy was found to further enhance the refinement effect. The melt thermal-rate treatment process present good grain refinement effect for Zn-50Al alloy and it was further promoted by the addition of Zn-Al-Ti-B-C master alloy into Zn-Al matrix.

The Microstructure and Mechanical Properties of Heat Treated NiCr20TiAl Superalloy

2016 ◽  
Vol 849 ◽  
pp. 531-536
Author(s):  
Ran Wei ◽  
Hui Yun Wu ◽  
Qing Quan Zhang ◽  
Ming Yang Li ◽  
Yu Cao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Vickers Hardness ◽  
Mechanical Performance ◽  
Cast Alloy ◽  
Energy Dispersive Spectrometer ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Age Hardening ◽  
Nickel Base Superalloy ◽  
Microstructure And Mechanical Properties

NiCr20TiAl is a typical age-hardening superalloy with Ni-Cr as matrix and γ′ as strengthening phase. The microstructure and mechanical properties of nickel base superalloy NiCr20TiAl under different heat treatment were examined by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), optical microscope (OM) and mechanical tester. The results showed that superior comprehensive mechanical performance of NiCr20TiAl cast alloy was achieved by 1050°C/8h, air cool (AC) +700°C/16h, AC treatment. The edge cracks problem was resolved by 1150°C/1h, water quench (WQ) solid solution treatment before cold rolling process. The vickers hardness of the alloy decreases from 308 to 148. The vickers hardness of the NiCr20TiAl alloy could be controlled below 250 by 1080°C/2min treatment.

scholarly journals Microstructural Improvement of Eutectic Al + Mg2Si Phases on Al–Zn–Si–Mg Cast Alloy with TiB2 Particles Additions

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2902
Author(s):  
Byungjoo Kim ◽  
Jihoon Hwang ◽  
Yongho Park ◽  
Youngcheol Lee
Keyword(s):  
Crystal Structure ◽  
Aluminum Alloys ◽  
Heterogeneous Nucleation ◽  
Cast Alloy ◽  
Mg2si Phase ◽  
Phase Modification ◽  
Polarizing Microscope ◽  
Nucleation Sites ◽  
Tib2 Particles

In this study, the effects of adding TiB2 particles to eutectic Al + Mg2Si phases in aluminum alloys were analyzed. The eutectic Al + Mg2Si phases were modified effectively when a large amount of TiB2 was added, and changes in the shape, size, and distribution of the eutectic Al + Mg2Si phases were confirmed using a polarizing microscope and FE-SEM. The crystal structure of the TiB2 particles and Mg2Si phases were analyzed using HR-TEM, and the analysis confirmed that the TiB2 particles can act as heterogeneous nucleation sites. This paper intends to clarify the principle of phase modification of the eutectic Al + Mg2Si phases by TiB2 particles and proposes a new mechanism to improve Mg2Si phase modification when TiB2 particles are added.

scholarly journals Preparation Process and Phase Transformation of Al-5Ti-0.25C Master Alloy Adopting Ti Machining Chips

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5783
Author(s):  
Sanbo Li ◽  
Chunfang Zhao ◽  
Fei Wang ◽  
Maoliang Hu ◽  
Zesheng Ji ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Master Alloy ◽  
Molten Aluminum ◽  
Energy Dispersive Spectrometer ◽  
Optical Microscope ◽  
Preparation Process ◽  
Simple Method ◽  
Master Alloys

The refining performance of Al-Ti-C master alloys is substantially compromised by the inferior wettability between graphite and molten aluminum. In this paper, the Al-5Ti-0.25C master alloy was successfully prepared by reacting Ti machining chips, graphite, and molten aluminum. In order to determine a simple method of improving the wettability, the optimal preparation process and phase transformation of the Al-5Ti-0.25C master alloy were investigated using an optical microscope, X-ray diffractometer, and scanning electron microscope equipped with an energy dispersive spectrometer. The results show that the feeding method using a prefabricated block made from Ti chips, Al chips, and graphite effectively improves the wettability between graphite and molten aluminum and increases the recovery rate of graphite. When the reaction temperature is low (1223 K), the agglomeration of TiAl3 is caused. When the reaction temperature is high (1373 K), the morphology of TiAl3 changes from block-like to needle-like and increases its size. Further, a short reaction time (30 min) results in the incomplete dissolution of the Ti chips, while a long reaction time (90 min) causes the TiAl3 to transform into needle-like morphologies. The microstructural observation of undissolved Ti chips shows that TiAl3 and TiC are formed around it, which proves the transformation of Ti chips to TiAl3 and TiC. In addition, the enrichment of TiC and Al4C3 was observed in the vicinity of TiAl3, and a reaction model for the formation of TiC from the reaction of Al4C3 and TiAl3 was presented.

scholarly journals Thermal Assessment of Modified Ultra-Light Magnesium-Lithium Alloys

2017 ◽  
Vol 62 (4) ◽  
pp. 2433-2440 ◽  
Author(s):  
M. Król ◽  
T. Mikuszewski ◽  
D. Kuc ◽  
T. Tański ◽  
E. Hadasik
Keyword(s):  
Grain Size ◽  
Master Alloy ◽  
Cast Alloy ◽  
Solidus Temperature ◽  
X Ray ◽  
Lithium Aluminium ◽  
Derivative Analysis ◽  
Master Alloys ◽  
Crystallisation Process ◽  
Cast Magnesium

AbstractThe paper presents the results of the influence of commercial TiBor and AlSr10 master alloys on the refine the grains size, hardness and crystallisation process based on the thermal-derivation analysis of light cast magnesium-lithium-aluminium alloys. The effects of TiBor and AlSr10 content on the characteristic parameters of the crystallisation process of Mg-Li-Al alloys were investigated by thermal-derivative analysis (TDA). Microstructural evaluations were identified by light microscope, X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy.The results showed that the addition of TiBor master alloy reduced the grain size of Mg-9Li-1.5Al cast alloy from 900 μm to 500 μm, while the addition of AlSr10 master alloy reduced the grain size of investigated cast alloy from 900 μm to 480 μm. Moreover, an addition of TiBor and AlSr10 simultaneously reduced the grain size from 900 μm to 430 μm.Results from the thermal-derivative analysis showed that the addition of grain refinement causes a decrease in nucleation temperature and solidus temperature.

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