scholarly journals Regulating Precipitates by Simple Cold Deformations to Strengthen Mg Alloys: A Review

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2507 ◽  
Author(s):  
Bo Song ◽  
Jia She ◽  
Ning Guo ◽  
Risheng Qiu ◽  
Hucheng Pan ◽  
...  
Keyword(s):  
Precipitation Hardening ◽  
Low Cost ◽  
Cold Deformation ◽  
High Strength ◽  
Mg Alloys ◽  
Strengthening Mechanisms ◽  
Precipitation Behavior ◽  
Research Directions ◽  
Hardening Effect ◽  
Peak Aged

Regulating precipitates is still an important issue in the development of high-strength Mg alloys, due to it determining the precipitation hardening effect. Cold deformation, as a simple and low-cost method, can remarkably influence the precipitate features. It is found that pre-cold deformation before aging can be utilized to enhance the precipitation hardening effect of Mg alloys. Moreover, post-deformation after aging could be an effective method to regulate precipitation orientation. In this review, recent research on the regulation of precipitation behavior by cold deformation in Mg-Al, Mg-Zn, and Mg-RE (RE: rare-earth elements) alloy systems was critically reviewed. The changes in precipitate features and mechanical properties of peak-aged Mg alloys via cold deformation were summarized. The corresponding strengthening mechanisms were also discussed. Finally, further research directions in this field were proposed.

Guiding principles for creating new high strength-high conductivity copper alloys

Impact ◽  
2020 ◽  
Vol 2020 (1) ◽  
pp. 71-73
Author(s):  
Satoshi Semboshi
Keyword(s):  
Low Cost ◽  
Copper Alloys ◽  
High Strength ◽  
Associate Professor ◽  
Aged Material ◽  
Contact Materials ◽  
Structure Control ◽  
Materials Research ◽  
Peak Aged ◽  
Nickel Silicon

Solid solution strengthened alloys such as brass and bronze have been widely used as contact materials for energisation in a range of devices due to the fact that they are relatively low cost. In more recent times precipitation strengthened alloys such as copper-beryllium, copper-titanium and copper-nickel-silicon are used due to their excellent strength and conductivity. Yet, little headway has been made in the development of precipitation hardening copper alloys due to the difficulty associated with departing from existing alloy designs and structure control methods. One team of researchers is exploring the use of over-aged material instead of the conventional peak-aged material. This is because previous studies have suggested that wires of this type may have improved strength and conductivity. But there remain many unknowns. Associate Professor Satoshi Semboshi is a researcher based at the Institute for Materials Research, Tohoku University, Japan, who is seeking to shed light on these unknowns.

Multiple strengthening mechanisms in high strength ultrafine-grained Al–Mg alloys

2020 ◽  
Vol 771 ◽  
pp. 138613 ◽  
Author(s):  
Hao Wang ◽  
Hongwei Geng ◽  
Dengshan Zhou ◽  
Kodai Niitsu ◽  
Ondrej Muránsky ◽  
...  
Keyword(s):  
High Strength ◽  
Mg Alloys ◽  
Strengthening Mechanisms ◽  
Ultrafine Grained ◽  
Al Mg Alloys

scholarly journals Microstructures and Mechanical Properties of Precipitation-Hardenable Magnesium–Silver–Calcium Alloy Sheets

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1632
Author(s):  
Mingzhe Bian ◽  
Xinsheng Huang ◽  
Yasumasa Chino
Keyword(s):  
Transverse Direction ◽  
Precipitation Hardening ◽  
Rolling Direction ◽  
High Strength ◽  
Alloy Sheet ◽  
Tensile Yield Strength ◽  
Strengthening Mechanisms ◽  
Solution Treated Condition ◽  
Solution Treated ◽  
Treated Condition

Precipitation hardening provides one of the most common strengthening mechanisms for magnesium (Mg) alloys. Here, we report a new precipitation-hardenable Mg sheet alloy based on the magnesium–silver–calcium system. In a solution treated condition (T4), the strength of Mg–xAg–0.1Ca alloys is enhanced with increasing the Ag content from 1.5 wt.% to 12 wt.%. The Mg–12Ag–0.1Ca (wt.%) alloy sheet shows moderate tensile yield strengths of 193 MPa, 130 MPa, 117 MPa along the rolling direction (RD), 45° and transverse direction (TD) in the T4-treated condition. Subsequent artificial aging at 170 °C for 336 h (T6) increases the tensile yield strengths to 236 MPa, 163 MPa and 143 MPa along the RD, 45° and TD, respectively. This improvement in the tensile yield strength by the T6 treatment can be ascribed to the formation of AgMg4 precipitates lying on the {112¯0}ɑ and pyramidal planes. Our finding is expected to stimulate the development of precipitation-hardenable Mg–Ag-based wrought alloys with high strength.

Effect of the Zn/Mg Ratio on Microstructure and Mechanical Properties in Al-Zn-Mg Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 479-482 ◽  
Author(s):  
Masatomo Nishi ◽  
Kenji Matsuda ◽  
Naoya Miura ◽  
Katsumi Watanabe ◽  
Susumu Ikeno ◽  
...  
Keyword(s):  
High Strength ◽  
Hardness Measurement ◽  
Tensile Tests ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Age Hardening ◽  
Peak Hardness ◽  
Number Density ◽  
Peak Aged Condition ◽  
Peak Aged

It is well know that the 7000 series Al-Zn-Mg alloy has good age hardening ability and high strength among commercial aluminum alloys. In this study, hardness measurement, tensile test, SEM and TEM observation have been performed in order to understand the effect of the Zn/Mg ratio on age hardening behaviour in Al-Zn-Mg alloys. It was seen from hardness measurement that the peak hardness increased with increasing amount of Zn and Mg. Tensile tests were performed for the samples of peak aged condition. It was seen that UTS increased with increasing amount of the Zn and Mg. The elongation decreased with increasing the amount of the Zn and Mg. Intregranular fracture was observed in alloys with low amount of Zn and Mg.Transgranular fracture was observed with high amount of Zn and Mg alloy. TEM observation was performed for peak aged samples. The size of precipitates became finer and the number density increased with increasing Zn and Mg contents.T’ Phase and h1 phase were observed in low Zn/Mg alloy. The h’ phase was observed in high Zn/Mg alloy.

Strengthening Mechanisms of Vanadium Micro-Alloyed Reinforcing Steel Bar

2011 ◽  
Vol 130-134 ◽  
pp. 942-945
Author(s):  
Lie Jun Li ◽  
Xiang Dong Huo ◽  
Lin Guo
Keyword(s):  
Yield Strength ◽  
Grain Refinement ◽  
Precipitation Hardening ◽  
High Strength ◽  
Experimental Methods ◽  
Strengthening Mechanisms ◽  
Large Numbers ◽  
Steel Bar ◽  
Micro Alloyed Steel ◽  
Grain Refinement Strengthening

High strength vanadium micro-alloyed steel with yield strength of 600MPa has been developed based on commercial 20MnSi steel bar. Experimental methods, such as OM, SEM and TEM, were used to study the experimental steels. Compared with 20MnSi, steel 20MnSiV boasts much finer microstructure, and large numbers of nanometer precipitates exist in the specimens of 20MnSiV. Analysis shows that strength of 20MnSiV dramatically increases through grain refinement strengthening and precipitation hardening of nanometer VCN particles.

scholarly journals Investigations of High-Strength Mg–Al–Ca–Mn Alloys with a Broad Range of Ca+Al Contents

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5439
Author(s):  
Stefan Gneiger ◽  
Nikolaus P. Papenberg ◽  
Aurel R. Arnoldt ◽  
Carina M. Schlögl ◽  
Martin Fehlbier
Keyword(s):  
Mechanical Performance ◽  
Low Cost ◽  
High Strength Steels ◽  
High Strength ◽  
High Volume ◽  
Mg Alloys ◽  
High Yield ◽  
Low Mass ◽  
Industrial Use ◽  
The Moment

The low mass and high specific stiffness of Mg alloys make them particularly interesting as means of transportation. Due to further desirable properties, such as good machinability and excellent castability, Mg alloys have gained acceptance as castings in high-volume applications, such as gearbox housings and automotive steering wheels. However, in forming processes, such as extrusion and forging, Mg alloys find little to no industrial use at the moment. The reasons for this are their poor formability, which is reflected in limited processing speeds and low ductility, and their modest mechanical performance, compared to competing materials, such as Al alloys and high-strength steels. Much research is being conducted worldwide on high-strength Mg alloys, most of which rely on high levels of rare earths, making these materials both ecologically and economically questionable. Here, it is shown that high yield strengths (> 300 MPa) can be achieved in the Mg–Al–Ca system while maintaining good ductility, using only low-cost elements. The investigations have shown that these properties can be adjusted over broad alloy compositions, which greatly simplifies both the processing and recyclability.

Tensile Properties of Cast and Hot Isostatic Pressurized Ti-6Al-4Fe-xSi Alloys

2004 ◽  
Vol 449-452 ◽  
pp. 689-692
Author(s):  
E.H. Kim ◽  
Hi Won Jeong ◽  
Seung Eon Kim ◽  
Yong Taek Hyun ◽  
Yont Tai Lee ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Tensile Properties ◽  
Room Temperature ◽  
Precipitation Hardening ◽  
Low Cost ◽  
High Strength ◽  
Alloy System ◽  
High Temperature Mechanical Properties ◽  
Better Than

A new high strength titanium alloy system with low cost alloying elements, such as Al, Fe, has been recently developed. In present study the expensive V was replaced with Fe, and Si was added from 0 to 7.5wt.%. The effect of Fe and Si on the microstructure and tensile properties of Ti-6Al-4Fe-xSi (x=0, 0.1, 0.25, 0.5, 0.75wt.%) alloys was investigated. The room and high temperature mechanical properties of Ti-6Al-4Fe alloys were better than those of the Ti-6Al-4V. It was mainly due to the phase boundary strengthening at ambient and high temperature. The strength and elongation of the developed alloys depended upon the Si contents. The Si elements made the grain boundary and colony size fine, and increased the strength of the developed alloys by solid solution and precipitation hardening. The tensile strength variation with the Si contents at room temperature and 400°C, and at 450°C and 500°C showed a similar behavior, respectively.

Aging Precipitation Behavior of Cu-Ag-Cr Alloy

2006 ◽  
Vol 118 ◽  
pp. 41-46 ◽  
Author(s):  
Jing Guo Lei ◽  
Ping Liu ◽  
Bao Hong Tian ◽  
Xiao Zhi ◽  
Xiao Tian Jing
Keyword(s):  
Cold Deformation ◽  
High Strength ◽  
Intermediate Stage ◽  
Precipitation Behavior ◽  
Annealing Temperatures ◽  
Aging Precipitation ◽  
Coarsening Behavior ◽  
High Annealing ◽  
Effects Of Aging ◽  
Aging Hardening

The Cu-Ag-Cr alloy is a kind of aging hardening copper alloy and has excellent combination properties of high strength and good electrical and thermal conductivity. In the present investigation, the aging precipitation behavior of Cu-Ag-Cr alloy is studied, and the effects of aging processes on the microstructure and properties are discussed. Emphasis is on the correlation between the coherency and coarsening behavior of the Cr precipitates. When the alloy aging at low annealing temperatures, the homogeneous dispersed Cr precipitates are observed to be approximately spherical and keep coherent with Cu matrix in the Cu-Ag-Cr alloy, the coherency is lost between at 450°C~520°C, coherency on coarsening process of Cr precipitates at high annealing temperatures, the radium for coherent / semi-coherent transition of the Cr precipitates is determined from TEM micrographs as 15-45nm. Aging in the intermediate stage, coherent and semi-coherent particles can co-exist(15<r<45nm). The precipitation can be accelerated by cold deformation before aging, the 60% deformed Cu-Ag-Cr alloy aging at 480°C for 1h, the hardness and electrical conductivity can respectively reach to 158HV and 85%IACS.

Hardening Mechanisms of Metals and Alloys Produced by SPD

2006 ◽  
Vol 503-504 ◽  
pp. 967-970 ◽  
Author(s):  
Satoshi Hashimoto ◽  
T. Suzuki ◽  
Alexei Vinogradov
Keyword(s):  
Solid Solution ◽  
Single Phase ◽  
Precipitation Hardening ◽  
High Strength ◽  
Solid Solution Hardening ◽  
Strengthening Mechanisms ◽  
Additive Character ◽  
Complex Process ◽  
Hardening Mechanisms

Strengthening is a complex process involving such basic mechanisms as dislocation accumulation (work hardening), Hall-Petch hardening due to grain refinement, solid solution hardening and precipitation hardening in various combinations. The contribution of different mechanisms into resultant strength can vary significantly depending on chemical composition and processing. The purpose of the present work is to explore the significance of SPD for hardening and to clarify the role of different strengthening mechanisms. The model Au-based system was employed using pure Au, single phase solid solution Au-25Ag and precipitation hardenable Au-12.5Ag-12.5Cu (in mass %) alloy subjected to ECAP. The additive character of different strengthening mechanisms is clearly demonstrated. The extremely high strength exceeding 1 GPa is achieved in the Au-Ag-Cu after ECAP followed by aging, which has never been attained in conventional processing schemes.

Copper-Alloyed PHFP Steel for Energy-Efficient and Distortion-Reduced Production of Cold-Formed, High-Strength Structural Components

2019 ◽  
Vol 959 ◽  
pp. 161-165
Author(s):  
Stefan Meiler ◽  
Frank Hoffmann ◽  
Hannah Schwich ◽  
Rudolf Kawalla ◽  
Wolfgang Bleck ◽  
...  
Keyword(s):  
Energy Efficient ◽  
Precipitation Hardening ◽  
High Strength ◽  
Structural Components ◽  
Hardening Effect ◽  
Effect Of Copper

This article reports on the development of a hardenable PHFP steel for energy-efficient and distortion-reduced production of cold-formed, high-strength structural components. Based on an alloying concept containing 0.8 wt.-% copper, a technology for the production of screws has been developed to exploit the precipitation-hardening effect of copper for increasing strength by tempering while avoiding final quenching.

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