scholarly journals Effect of Transition Metal Elements on High-Temperature Properties of Al–Si–Cu–Mg Alloys

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 357
Author(s):  
Chao Gao ◽  
Lingkun Zhang ◽  
Bingrong Zhang
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Transition Metal ◽  
Yield Strength ◽  
High Temperatures ◽  
Test Temperature ◽  
Intermetallic Phases ◽  
Mg Alloys ◽  
Metal Elements ◽  
Transition Metal Elements

In the present work, we studied the effects of transition metal elements on microstructure evolution and high-temperature mechanical properties via the preparation of new modified alloys with micro-additions of Cr, Ti, V, Zr, Mo, and Mn to address the poor high-temperature performance of Al–Si–Cu–Mg alloys for automotive engines. The results show that the addition of transition metal elements formed a variety of new intermetallic phases that were stable at high temperatures, such as (AlSi)3(TiVZr), (AlSi)3Ti, (AlSi)3(CrVTi), Al74Si6Mn4Cr2Fe, Al85Si5Mn2Mo2CrFe, Al0.78Fe4.8Mn0.27Mo4.15Si2, (AlSi)2(CrVTi)Mo, and Al13(MoCrVTi)4Si4, and these phases evidently improved the ultimate high-temperature tensile strength and yield strength. The ultimate tensile strength and yield strength of the modified alloy increased by 17.49% and 31.65% when the test temperature increased to 240 °C, respectively, and by 71.28% and 74.73% when the test temperature increased to 300 °C, respectively. The fundamental reason for this change is that the intermetallic phase hinders the expansion of cracks, which can exist stably at high temperatures. When a crack extends to the intermetallic phases, it will break along with the intermetallic phases or propagate along the morphological edge of the intermetallic phases.

scholarly journals The Influence of La and Ce on Microstructure and Mechanical Properties of an Al-Si-Cu-Mg-Fe Alloy at High Temperature

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 384
Author(s):  
Andong Du ◽  
Anders E. W. Jarfors ◽  
Jinchuan Zheng ◽  
Kaikun Wang ◽  
Gegang Yu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Temperature ◽  
Intermetallic Phases ◽  
High Temperature Strength ◽  
Thermal Expansion Mismatch ◽  
Strengthening Mechanisms ◽  
High Temperature Mechanical Properties ◽  
Minor Contribution ◽  
A Minor

The effect of lanthanum (La)+cerium (Ce) addition on the high-temperature strength of an aluminum (Al)–silicon (Si)–copper (Cu)–magnesium (Mg)–iron (Fe)–manganese (Mn) alloy was investigated. A great number of plate-like intermetallics, Al11(Ce, La)3- and blocky α-Al15(Fe, Mn)3Si2-precipitates, were observed. The results showed that the high-temperature mechanical properties depended strongly on the amount and morphology of the intermetallic phases formed. The precipitated tiny Al11(Ce, La)3 and α-Al15(Fe, Mn)3Si2 both contributed to the high-temperature mechanical properties, especially at 300 °C and 400 °C. The formation of coarse plate-like Al11(Ce, La)3, at the highest (Ce-La) additions, reduced the mechanical properties at (≤300) ℃ and improved the properties at 400 ℃. Analysis of the strengthening mechanisms revealed that the load-bearing mechanism was the main contributing mechanism with no contribution from thermal-expansion mismatch effects. Strain hardening had a minor contribution to the tensile strength at high-temperature.

Effect of Long-Period Stacking Order Phase and α-Mg Phase on Strength and Ductility of Mg-Zn-Y Alloy

2012 ◽  
Vol 706-709 ◽  
pp. 1237-1242 ◽  
Author(s):  
Masafumi Noda ◽  
Yoshihito Kawamura
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
High Temperatures ◽  
Mg Alloys ◽  
Tensile Yield Strength ◽  
Block Type ◽  
Lpso Phase ◽  
Long Period ◽  
Stacking Order ◽  
Type Phase

Mg alloys are lightweight structural alloys that normally have a good castability and machinability as well as an excellent specific strength and rigidity. However, the mechanical properties of Mg alloys are inferior to those of Al alloys, and their range of industrial applications is limited. Recently, Mg–Zn–Y alloy has been found to show a high tensile yield strength with a good elongation. The alloy has a long-period stacking order (LPSO) phase as the secondary phase in an α-Mg phase. In general, the tensile yield strengths of LPSO-type Mg alloy are known to be markedly enhanced by the formation of kink bands in the LPSO phase and by microstructural refinement of the α-Mg phase during plastic deformation. The separate roles of the LPSO phase and the α-Mg phase in relation to the mechanical properties of high-strength LPSO-type Mg alloy were investigated at ambient and high temperatures. For high strengths at ambient and high temperatures, it was important that the α-Mg phase consisted of a fine-grain region and a nonrecrystallized region, and that the LPSO phase remained as a block-type phase. On the other hands, it was necessary to change the LPSO phase from a block-type phase into a plate-type phase by heat treatment before tensile testing to improve the ductility of the alloy while maintaining its tensile yield strength. Microstructural control of the LPSO phase and the α-Mg phase is necessary to obtained Mg–Zn–Y alloy with superior mechanical properties at ambient-to-high temperatures.

New Class of Diluted Ferromagnetic Semiconductors based on CaO without Transition Metal Elements

2004 ◽  
Vol 43 (No. 7A) ◽  
pp. L934-L936 ◽  
Author(s):  
Kazuhide Kenmochi ◽  
Masayoshi Seike ◽  
Kazunori Sato ◽  
Akira Yanase ◽  
Hiroshi Katayama-Yoshida
Keyword(s):  
Transition Metal ◽  
Ferromagnetic Semiconductors ◽  
Metal Elements ◽  
New Class ◽  
Transition Metal Elements

scholarly journals Polarizable Charge Equilibration Model for Transition-Metal Elements

2018 ◽  
Vol 122 (48) ◽  
pp. 9350-9358 ◽  
Author(s):  
Soonho Kwon ◽  
Saber Naserifar ◽  
Hyuck Mo Lee ◽  
William A. Goddard
Keyword(s):  
Transition Metal ◽  
Metal Elements ◽  
Charge Equilibration ◽  
Equilibration Model ◽  
Transition Metal Elements

scholarly journals Preparation and Magnetic Properties of X-type Hexaferrites with Transition Metal Elements

2010 ◽  
Vol 57 (12) ◽  
pp. 809-813
Author(s):  
Nobuyuki Hosaka ◽  
Kenji Kamishima ◽  
Koichi Kakizaki ◽  
Nobuyuki Hiratsuka
Keyword(s):  
Magnetic Properties ◽  
Transition Metal ◽  
Metal Elements ◽  
Transition Metal Elements
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