scholarly journals Processing of Cu-Cr alloy for combined high strength and high conductivity

2017 ◽  
Vol 26 (2) ◽  
pp. 11-20
Author(s):  
A.O Olofinjana ◽  
A. and K. S. Tan
Keyword(s):  
Solid Solution ◽  
Rapid Solidification ◽  
High Strength ◽  
Casting Process ◽  
High Conductivity ◽  
Volume Proportion ◽  
Combined Solution ◽  
Peak Aging ◽  
Peak Aged ◽  
Cr Concentration

High strength and high conductivity (HSHC) are two intrinsic properties difficult to combine in metallic alloy design because; almost all strengthening mechanisms also lead to reduced conductivity. Precipitation hardening by nano-sized precipitates had proven to be the most adequate way to achieve the optimum combination of strength and conductivity in copper based alloys. However, established precipitation strengthened Cu- alloys are limited to very dilute concentration of solutes thereby limiting the volume proportion hardening precipitates. In this work, we report the investigation of the reprocessing of higher Cr concentration Cu- based alloys via rapid solidification. It is found that the rapid solidification in the as-cast ribbon imposed combined solution extension and ultra-refinement of Cr rich phases. X-ray diffraction evidences suggest that the solid solution extension was up to 6wt%Cr. Lattice parameters determined confirmed the many folds extension of solid solution of Cr in Cu. Thermal aging studies of the cast ribbons indicated that peak aging treatments occurred in about twenty minutes. Peak aged hardness ranged from about 200 to well over 300Hv. The maximum peak aged hardness of 380Hv was obtained for alloy containing 6wt.%Cr but with conductivity of about 50%IACS. The best combined strength/conductivity was obtained for 4wt.%Cr alloy with hardness of 350HV and conductivity of 80% IACS. The high strengths observed are attributed to the increased volume proportion of semi-coherent Cr rich nano-sized precipitates that evolved from the supersaturated solid solution of Cu-Cr that was achieved from the high cooling rates imposed by the ribbon casting process. The rapid overaging of the high Cr concentration Cu-Cr alloy is still a cause for concern in optimising the process for reaching peak HSHC properties. It is still important to investigate a microstructural design to slow or severely restrict the overaging process. The optimum HSHC property reported here is a rare combination of high strength (>350Hv ~ 900MPa) and conductivity (50 – 80% IACS) found in metallic alloys.

scholarly journals Processing of Cu-Cr alloy for combined high strength and high conductivity

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
A.O Olofinjana and ◽  
A. and K. S. Tan
Keyword(s):  
Solid Solution ◽  
Rapid Solidification ◽  
High Strength ◽  
Casting Process ◽  
High Conductivity ◽  
Volume Proportion ◽  
Combined Solution ◽  
Peak Aging ◽  
Peak Aged ◽  
Cr Concentration

High strength and high conductivity (HSHC) are two intrinsic properties difficult to combine in metallic alloy design because; almost all strengthening mechanisms also lead to reduced conductivity. Precipitation hardening by nano-sized precipitates had proven to be the most adequate way to achieve the optimum combination of strength and conductivity in copper based alloys. However, established precipitation strengthened Cu- alloys are limited to very dilute concentration of solutes thereby limiting the volume proportion hardening precipitates. In this work, we report the investigation of the reprocessing of higher Cr concentration Cu- based alloys via rapid solidification. It is found that the rapid solidification in the as-cast ribbon imposed combined solution extension and ultra-refinement of Cr rich phases. X-ray diffraction evidences suggest that the solid solution extension was up to 6wt%Cr. Lattice parameters determined confirmed the many folds extension of solid solution of Cr in Cu. Thermal aging studies of the cast ribbons indicated that peak aging treatments occurred in about twenty minutes. Peak aged hardness ranged from about 200 to well over 300Hv. The maximum peak aged hardness of 380Hv was obtained for alloy containing 6wt.%Cr but with conductivity of about 50%IACS. The best combined strength/conductivity was obtained for 4wt.%Cr alloy with hardness of 350HV and conductivity of 80% IACS. The high strengths observed are attributed to the increased volume proportion of semi-coherent Cr rich nano-sized precipitates that evolved from the supersaturated solid solution of Cu-Cr that was achieved from the high cooling rates imposed by the ribbon casting process. The rapid overaging of the high Cr concentration Cu-Cr alloy is still a cause for concern in optimising the process for reaching peak HSHC properties. It is still important to investigate a microstructural design to slow or severely restrict the overaging process. The optimum HSHC property reported here is a rare combination of high strength (>350Hv ~ 900MPa) and conductivity (50 – 80% IACS) found in metallic alloys.

scholarly journals Processing of Cu-Cr alloy for combined high strength and high conductivity

2017 ◽  
Vol 27 (2) ◽  
pp. 11-20
Author(s):  
A.O Olofinjanaa ◽  
K. S. Tan
Keyword(s):  
Solid Solution ◽  
Rapid Solidification ◽  
High Strength ◽  
Casting Process ◽  
High Conductivity ◽  
Volume Proportion ◽  
Combined Solution ◽  
Peak Aging ◽  
Peak Aged ◽  
Cr Concentration

High strength and high conductivity (HSHC) are two intrinsic properties difficult to combine in metallic alloy design because; almost all strengthening mechanisms also lead to reduced conductivity. Precipitation hardening by nano-sized precipitates had proven to be the most adequate way to achieve the optimum combination of strength and conductivity in copper based alloys. However, established precipitation strengthened Cu- alloys are limited to very dilute concentration of solutes thereby limiting the volume proportion hardening precipitates. In this work, we report the investigation of the reprocessing of higher Cr concentration Cu- based alloys via rapid solidification. It is found that the rapid solidification in the as-cast ribbon imposed combined solution extension and ultra-refinement of Cr rich phases. X-ray diffraction evidences suggest that the solid solution extension was up to 6wt%Cr.Lattice parameters determined confirmed the many folds extension of solid solution of Cr in Cu.  Thermal aging studies of the cast ribbons indicated that peak aging treatments occurred in about twenty minutes. Peak aged hardness ranged from about 200 to well over 300Hv. The maximum peak aged hardness of 380Hv was obtained for alloy containing 6wt.%Cr but with conductivity of about 50%IACS. The best combined strength/conductivity was obtained for 4wt.%Cr  alloy with hardness of 350HV and conductivity of 80% IACS. The high strengths observed are attributed to the increased volume proportion of semi-coherent Cr rich nano-sized precipitates that evolved from the supersaturated solid solution of Cu-Cr that was achieved from the high cooling rates imposed by the ribbon casting process. The rapid overaging of the high Cr concentration Cu-Cr alloy is still a cause for concern in optimising the process for reaching peak HSHC properties. It is still important to investigate a microstructural design to slow or severely restrict the overaging process. The optimum HSHC property reported here is a rare combination of high strength (>350Hv ~ 900MPa) and conductivity (50 – 80% IACS) found in metallic alloys. 

Development of high-strength, high-conductivity copper alloys by rapid solidification

1992 ◽  
Vol 11 (16) ◽  
pp. 1104-1106 ◽  
Author(s):  
J. A. Juarez-Islas ◽  
R. Perez ◽  
L. A. Albarran ◽  
V. Rivera ◽  
L. Martinez
Keyword(s):  
Rapid Solidification ◽  
Copper Alloys ◽  
High Strength ◽  
High Conductivity

Rapid solidification of copper alloys with high strength and high conductivity

1997 ◽  
Vol 6 (5) ◽  
pp. 611-614 ◽  
Author(s):  
F. Lopez ◽  
J. Reyes ◽  
B. Campillo ◽  
G. Aguilar-Sahagun ◽  
J. A. Juarez-lslas
Keyword(s):  
Rapid Solidification ◽  
Copper Alloys ◽  
High Strength ◽  
High Conductivity

A new high strength, high conductivity Cu-0.5wt.%Zr alloy produced by rapid solidification technology

1986 ◽  
Vol 83 (1) ◽  
pp. 115-121 ◽  
Author(s):  
L. Arnberg ◽  
U. Backmark ◽  
N. Bäckström ◽  
J. Lange
Keyword(s):  
Rapid Solidification ◽  
High Strength ◽  
High Conductivity ◽  
Solidification Technology ◽  
Rapid Solidification Technology ◽  
Zr Alloy

Microstructures in explosively consolidated rapidly solidified aluminum powders

1986 ◽  
Vol 44 ◽  
pp. 428-429
Author(s):  
T. E. Doyle ◽  
R. N. Wright ◽  
J. E. Flinn ◽  
G. E. Korth
Keyword(s):  
Solid Solution ◽  
Rapid Solidification ◽  
Pure Aluminum ◽  
Analytical Electron Microscopy ◽  
High Strength ◽  
Bulk Temperature ◽  
Subgrain Structure ◽  
Aluminum Powders ◽  
Aerospace Applications ◽  
Particle Bonding

Rapid solidification technology offers the possibility of producing unique, high-strength aluminum alloys to replace titanium in low-temperature aerospace applications. One such new alloy, an extended solid solution in the Al-Co system, was examined in the present work. Although rapid solidification can produce an extended solid solution, the solid solution is prone to decomposition because of cobalt's very limited solubility in aluminum. Dynamic consolidation is a relatively low bulk temperature process and presented the best opportunity for retaining the solid solution in monolithic forms. Analytical electron microscopy was used to study precipitation, grain and subgrain structure, and particle-bonding mechanisms in consolidated Al-Co and pure aluminum powders.

The Microstructure and Mechanical Properties of Super-High Strength Al Alloys by Spray Forming

2012 ◽  
Vol 535-537 ◽  
pp. 909-914
Author(s):  
Guo Wei Zhang ◽  
Zhen Chen ◽  
Wei Chen ◽  
Hai Ying Xin ◽  
Jing Zhai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
High Strength ◽  
Spray Forming ◽  
Al Alloys ◽  
Microstructure And Properties ◽  
Cu Alloys ◽  
Peak Aging

To analysis the microstructure and properties of super-high strength Al-Zn-Mg-Cu alloys containing Zr ,Ni and Mn, the apparatus of SEM、TEM、and Tensile machine was used. The results show that the microstructure was fine and homogeneous, the phases became finer for the alloys with adding Zr, Mn, Ni than the alloy with Zr only after solid solution. The ultimate tensile strength of the alloy was 850MPa and the elongation was 5% respectively at peak aging.

Severe Plastic Deformation of Copper, Binary Cu-Zn Solid-Solution Alloys, and High-Strength Brass by High-Pressure Torsion

2021 ◽  
Vol 1016 ◽  
pp. 780-785
Author(s):  
Takahiro Kunimine
Keyword(s):  
Solid Solution ◽  
Plastic Deformation ◽  
High Pressure ◽  
Severe Plastic Deformation ◽  
High Pressure Torsion ◽  
Copper Alloys ◽  
Pure Copper ◽  
High Strength ◽  
Casting Process ◽  
Β Phase

Severely-deformed high-strength brasses were investigated by leveraging high-pressure torsion (HPT) processing in order to obtain more enhanced mechanical properties of copper alloys. Pure copper, binary Cu-Zn solid-solution alloys and high-strength brasses including aluminum and manganese additions were selected for experiments. For comparison of these materials, zinc equivalent parameter was used. These materials were subjected to the HPT processing, followed by hardness tests and tensile tests. The maximal hardness value of the nanostructured high-strength brass with β phase matrix was reached 420 HV. The HPT processed high-strength brass with β phase matrix showed significant increase in the yield stress and tensile strength with sacrificing ductility. The tensile specimen of the high-strength brass with β phase matrix was fractured before initiation of necking. It was found that utilizing β phase matrix is also beneficial for controlling enhanced strength of high-strength copper alloys for not only casting process but also severe plastic deformation.

scholarly journals Comparative Study of Two Aging Treatments on Microstructure and Mechanical Properties of an Ultra-Fine Grained Mg-10Y-6Gd-1.5Zn-0.5Zr Alloy

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 658 ◽  
Author(s):  
Huan Liu ◽  
He Huang ◽  
Ce Wang ◽  
Jia Ju ◽  
Jiapeng Sun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Aging Treatment ◽  
High Strength ◽  
Tensile Tests ◽  
Aged Alloy ◽  
Fine Grained ◽  
Peak Aging ◽  
Peak Aged ◽  
Strength And Ductility

Developing high strength and high ductility magnesium alloys is an important issue for weight-reduction applications. In this work, we explored the feasibility of manipulating nanosized precipitates on LPSO-contained (long period stacking ordered phase) ultra-fine grained (UFG) magnesium alloy to obtain simultaneously improved strength and ductility. The effect of two aging treatments on microstructures and mechanical properties of an UFG Mg-10Y-6Gd-1.5Zn-0.5Zr alloy was systematically investigated and compared by a series of microstructure characterization techniques and tensile test. The results showed that nano γ’’ precipitates were successfully introduced in T5 peak aged alloy with no obvious increase in grain size. While T6 peak aging treatment stimulated the growth of α-Mg grains to 4.3 μm (fine grained, FG), together with the precipitation of γ’’ precipitates. Tensile tests revealed that both aging treatments remarkably improved the strengths but impaired the ductility slightly. The T5 peak aged alloy exhibited the optimum mechanical properties with ultimate strength of 431 MPa and elongation of 13.5%. This work provided a novel strategy to simultaneously improve the strength and ductility of magnesium alloys by integrating the intense precipitation strengthening with ductile LPSO-contained UFG/FG microstructure.

Deformation and fracture behavior of an Al-Li-Cu-Mg-Zr alloy 8090

1990 ◽  
Vol 48 (4) ◽  
pp. 974-975
Author(s):  
D.M. Jiang ◽  
B.D. Hong
Keyword(s):  
High Strength ◽  
Deformation And Fracture ◽  
Fracture Behaviors ◽  
Aluminum Lithium ◽  
Carbon Fiber Reinforced Composites ◽  
Peak Aged ◽  
Aluminum Lithium Alloys ◽  
High Strength Aluminum Alloys ◽  
Lithium Alloys ◽  
Zr Alloy

Aluminum-lithium alloys have been recently got strong interests especially in the aircraft industry. Compared to conventional high strength aluminum alloys of the 2000 or 7000 series it is anticipated that these alloys offer a 10% increase in the stiffness and a 10% decrease in density, thus making them rather competitive to new up-coming non-metallic materials like carbon fiber reinforced composites.The object of the present paper is to evaluate the inluence of various microstructural features on the monotonic and cyclic deformation and fracture behaviors of Al-Li based alloy. The material used was 8090 alloy. After solution treated and waster quenched, the alloy was underaged (190°Clh), peak-aged (190°C24h) and overaged (150°C4h+230°C16h). The alloy in different aging condition was tensile and fatigue tested, the resultant fractures were observed in SEM. The deformation behavior was studied in TEM.

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