Design of High-Strength, High-Conductivity Alloys

MRS Bulletin ◽  
1996 ◽  
Vol 21 (6) ◽  
pp. 13-18 ◽  
Author(s):  
J. Miyake ◽  
G. Ghosh ◽  
M.E. Fine
Keyword(s):  
Electrical Conductivity ◽  
Computer Aided Design ◽  
Volume Fraction ◽  
High Strength ◽  
Pure Metal ◽  
Alloy Design ◽  
High Conductivity ◽  
Solid Solution Strengthening ◽  
Computer Aided ◽  
The Matrix

Computer-aided design of alloys is becoming increasingly useful, replacing the completely experimental approach. The computer-aided approach significantly reduces the cost of alloy design and more easily leads to optimum properties by reducing the amount of experimentation. Design of high-strength, high-conductivity alloys is a good example of the efficacy of using the computer to design experimental alloys.Alloys that have both high strength and high electrical conductivity are needed for many applications such as lead frames, connectors, conducting springs, and sliding contacts. Figure 1 shows the strength and conductivity of some commercially available copper-based alloys. Since dissolved solutes in an otherwise pure metal rapidly reduce the electrical conductivity (as well as the thermal conductivity), solid solution strengthening is not suitable for designing this class of alloys. Such alloys must be designed on the basis of precipitation or dispersion hardening. The theory of the yield stress of alloys with precipitates or dispersed phases has been well-formulated and may be used for alloy design. The solubility of the hardening phase in the matrix must be very small. Otherwise the conductivity will be degraded too much. Nordheim's rule relates conductivity to dissolved solute in alloys and is also available for alloy design. Decreasing the dissolved solute increases the conductivity and strength due to an increase in the volume fraction of the precipitate.

scholarly journals Fabricate of High-Strength and High-Conductivity Cu–Cr–Si Alloys through ECAP-Bc and Aging Heat Treatment

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1603 ◽  
Author(s):  
Tingbiao Guo ◽  
Junjie Wang ◽  
Yibo Wu ◽  
Xiaoyang Tai ◽  
Zhi Jia ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electron Backscatter Diffraction ◽  
Aging Treatment ◽  
High Strength ◽  
High Conductivity ◽  
Grain Structure ◽  
X Ray Diffraction ◽  
Angular Pressing ◽  
The Matrix ◽  
Backscatter Diffraction

The effect of equal channel angular pressing (ECAP) through the route Bc and aging treatment on the grain structure and properties of the Cu–1Cr–0.2Si alloy was investigated. Microstructure was detected by scanning electron microscopy (SEM), x-ray diffraction (XRD), and electron backscatter diffraction (EBSD) and the mechanical properties and electrical conductivity were tested. Results shown that after ECAP, accompanying the grains refined to nano-and submicron-structure, the Cr particles were gradually spread along the grain boundaries (GBs), aging treatment promoted Cr particles dispersed in the matrix. ECAP greatly increased the ultimate tensile strength (UTS) while having a small effect on the conductivity, and aging treatment increased electrical conductivity. The stable {111}<110> texture after ECAP and the lower dislocation density after aging treatment maybe the main reasons for the high conductivity of the material.

Microstructure and properties of high-conductivity, super-high-strength Cu–8.0Ni–1.8Si–0.6Sn–0.15Mg alloy

2009 ◽  
Vol 24 (6) ◽  
pp. 2123-2129 ◽  
Author(s):  
Z. Li ◽  
Z.Y. Pan ◽  
Y.Y. Zhao ◽  
Z. Xiao ◽  
M.P. Wang
Keyword(s):  
Electrical Conductivity ◽  
Processing Condition ◽  
Solution Treatment ◽  
High Strength ◽  
High Conductivity ◽  
Age Hardening ◽  
Transmission Electron ◽  
The Matrix ◽  
Strength Alloy ◽  
Evolution Of Microstructure

A high-conductivity and super-high-strength alloy, Cu-8.0Ni-1.8Si-0.6Sn-0.15Mg, has been developed. The processing conditions of the alloy have been investigated. The evolution of microstructure of the alloy on aging has been examined by transmission electron microscopy. The processing condition giving the highest hardness and good electrical conductivity is as follows: solution treatment at 970 °C for 4 h, cold rolling to 60% reduction, and aging at 500 °C for 30 min. The processed alloy has an average tensile strength of 1180 MPa, 0.2% proof strength of 795 MPa, elongation of 2.75%, and average electrical conductivity of 26.5% IACS. Orthorhombic Ni2Si precipitates are responsible for the age-hardening effect. The orientation relationship between the precipitates and the matrix is (110)m(211)p and. DO22 ordering together with spinodal decomposition also contributed to the hardening.

Mechanical Properties of Densified Untwisted Carbon Nanotube Yarn / Epoxy Composites

2015 ◽  
Author(s):  
Risa Yoshizaki ◽  
Kim Tae Sung ◽  
Atsushi Hosoi ◽  
Hiroyuki Kawada
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Polymer Matrix Composites ◽  
High Strength ◽  
Matrix Composites ◽  
Specific Strength ◽  
The Matrix ◽  
Cnt Arrays ◽  
Strength And Stiffness ◽  
Long Fibers

Carbon nanotubes (CNTs) have very high specific strength and stiffness. The excellent properties make it possible to enhance the mechanical properties of polymer matrix composites. However, it is difficult to use CNTs as the reinforcement of long fibers because of the limitation of CNT growth. In recent years, a method to spin yarns from CNT forests has developed. We have succeeded in manufacturing the unidirectional composites reinforced with the densified untwisted CNT yarns. The untwisted CNT yarns have been manufactured by drawing CNTs through a die from vertically aligned CNT arrays. In this study, the densified untwisted CNT yarns with a polymer treatment were fabricated. The tensile strength and the elastic modulus of the yarns were improved significantly by the treatment, and they were 1.9 GPa and 140 GPa, respectively. Moreover, the polymer treatment prevented the CNT yarns from swelling due to impregnation of the matrix resin. Finally, the high strength CNT yarn composites which have higher volume fraction than a conventional method were successfully fabricated.

A Methodology for Synthesizing High-Performance Robots Fabricated With Optimally Tailored Composite Laminates

1987 ◽  
Vol 109 (1) ◽  
pp. 74-86 ◽  
Author(s):  
C. K. Sung ◽  
B. S. Thompson
Keyword(s):  
Composite Laminates ◽  
High Performance ◽  
Volume Fraction ◽  
Three Dimensional ◽  
High Strength ◽  
Fiber Volume ◽  
Cross Sectional ◽  
Fiber Properties ◽  
Robot Arms ◽  
The Matrix

An essential ingredient of the next generation of robotic manipulators will be high-strength lightweight arms which promise high-performance characteristics. Currently, a design methodology for optimally synthesizing these essential robotic components does not exist. Herein, an approach is developed for addressing this void in the technology-base by integrating state-of-the-art techniques in both the science of composite materials and also the science of flexible robotic systems. This approach is based on the proposition that optimal performance can be achieved by fabricating robot arms with optimal cross-sectional geometries fabricated with optimally tailored composite laminates. A methodology is developed herein which synthesizes the manufacturing specification for laminates which are specifically tailored for robotic applications in which both high-strength, high-stiffness robot arms are required which also possess high material damping. The parameters in the manufacturing specification include the fiber-volume fraction, the matrix properties, the fiber properties, the ply layups, the stacking sequence and the ply thicknesses. This capability is then integrated within a finite-element methodology for analyzing the dynamic response of flexible robots. An illustrative example demonstrates the approach by simulating the three-dimensional elastodynamic response of a robot subjected to a prescribed spatial maneuver.

scholarly journals PHASE-TRANSFORMATION DYNAMICS AND CHARACTERIZATION OF PRECIPITATES IN THE Cu-3Ti-3Ni-0.5Si ALLOY

2021 ◽  
Vol 55 (4) ◽  
Author(s):  
Jia Liu ◽  
Jituo Liu ◽  
Xianhui Wang ◽  
Chong Fu ◽  
Yanlong Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Phase Transformation ◽  
Volume Fraction ◽  
Formation Enthalpy ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
The Matrix ◽  
Diffraction Patterns ◽  
Precipitated Phases

In this paper we investigated the phase-transformation dynamics of the Cu-3Ti-3Ni-0.5Si alloy by applying the Avrami method to phase-transformation dynamics and electrical conductivity based on the relationship between the electrical conductivity and the volume fraction of precipitates in the Cu-3Ti-3Ni-0.5Si alloy. The results corroborated well with the experimental data. The microstructure and precipitated phases were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The analysis of the selected-area electron-diffraction patterns indicated that the precipitates formed in the matrix of the Cu-3Ti-3Ni-0.5Si alloy during aging, correspond to the Ni3Ti, Ni3Si, and Ni2Si phases. According to the values of formation enthalpy and cohesive energy determined by first-principle calculations, the formation of the Ni2Si phase is more favorable compared to the Ni3Si and Ni3Ti phases, and the Ni3Ti exhibits improved structural stability compared to the Ni2Si and Ni3Si phases.

scholarly journals Rheological and Mechanical Properties of Silica/Nitrile Butadiene Rubber Vulcanizates with Eco-Friendly Ionic Liquid

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2763
Author(s):  
Munir Hussain ◽  
Sohail Yasin ◽  
Hafeezullah Memon ◽  
Zhiyun Li ◽  
Xinpeng Fan ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Volume Fraction ◽  
High Strength ◽  
Crosslinking Density ◽  
Mechanical And Thermal Properties ◽  
Butadiene Rubber ◽  
Transmission Electron ◽  
The Matrix ◽  
Silica Dispersion ◽  
The Impact

In this paper we designed greener rubber nanocomposites exhibiting high crosslinking density, and excellent mechanical and thermal properties, with a potential application in technical fields including high-strength and heat-resistance products. Herein 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) ionic liquid was combined with silane coupling agent to formulate the nanocomposites. The impact of [EMIM]OAc on silica dispersion in a nitrile rubber (NBR) matrix was investigated by a transmission electron microscope and scanning electron microscopy. The combined use of the ionic liquid and silane in an NBR/silica system facilitates the homogeneous dispersion of the silica volume fraction (φ) from 0.041 to 0.177 and enhances crosslinking density of the matrix up to three-fold in comparison with neat NBR, and also it is beneficial for solving the risks of alcohol emission and ignition during the rubber manufacturing. The introduction of ionic liquid greatly improves the mechanical strength (9.7 MPa) with respect to neat NBR vulcanizate, especially at high temperatures e.g., 100 °C. Furthermore, it impacts on rheological behaviors of the nanocomposites and tends to reduce energy dissipation for the vulcanizates under large amplitude dynamic shear deformation.

THE EFFECTS OF DEBULKING ON THE MICROSTRUCTURE OF CARBON FIBER REINFORCED COMPOSITES

2021 ◽  
Author(s):  
MATHEW SCHEY ◽  
SCOTT STAPLETON ◽  
TIBOR BEKE
Keyword(s):  
Carbon Fiber ◽  
Volume Fraction ◽  
Weight Ratio ◽  
High Strength ◽  
Fiber Reinforced ◽  
Reinforced Plastics ◽  
Three Samples ◽  
The Matrix ◽  
Carbon Fiber Reinforced Composites ◽  
Carbon Fiber Reinforced

Carbon fiber reinforced plastics (CFRPs) are widely used due to their high strength to weight ratios. A common process manufacturers use to increase the strength to weight ratio is debulking. Debulking is the process of transversely compacting a dry fibrous reinforcement prior to wet out with the matrix resin, in order to induce fiber nesting, effectively increasing the volume fraction of the sample. While this process is widely understood macroscopically its effects on fibrous microstructures have not yet been well characterized. The aim of this work is to compare the microstructures of three CFRPs, varying only the debulking step in the manufacturing process. The microstructural effects of debulking on three unidirectional CFRPs made from three different levels of debulking were studied. High resolution serial sections of all three samples were taken using the UES ROBO-MET at the NASA Glenn Research Center in Cleveland, Ohio. Using these scans, the fiber positions were measured and connected to make fiber paths. Statistical descriptors such as local fiber and void volume fractions, and void distribution and morphology were then generated for each sample and compared. Using these descriptors, the effects of debulking on the composite microstructure can be measured.

A Study on Mechanical Properties and Strengthening Mechanisms of AA5052/ZrB2 In Situ Composites

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Narendra Kumar ◽  
Gaurav Gautam ◽  
Rakesh Kumar Gautam ◽  
Anita Mohan ◽  
Sunil Mohan
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
High Strength ◽  
Strengthening Mechanism ◽  
Strengthening Mechanisms ◽  
In Situ Composites ◽  
Solid Solution Strengthening ◽  
Theoretical Yield ◽  
The Matrix

In the present study, in situ reaction technique has been employed to prepare AA5052 matrix composites reinforced with different vol. % of ZrB2 particles (i.e., 0, 4.5, and 9 vol. %). Composites have been characterized by X-ray diffraction (XRD) to confirm the in situ formation of ZrB2 particles in the matrix. Optical Microscopy (OM) studies reveal the refinement of aluminum-rich phase due to the presence of ZrB2 particles. Scanning electron microscopy (SEM) studies reveal size and distribution of ZrB2 particles while transmission electron microscopy (TEM) reveals the presence of dislocations in the matrix around ZrB2 particles. Hardness and tensile testing of composites have been carried out at room temperature to evaluate the mechanical properties. The results reveal the improvement in hardness and strength with increased amount of ZrB2 particles. Strength of AA5052/ZrB2 in situ composites has been analyzed by various strengthening mechanism models. The analysis revealed that Orowan and Solid solution strengthening mechanisms are the predominant mechanism for high strength composites. Theoretical yield strength is about 6–10% higher than the experimental values due to clustering tendency of ZrB2 particles.

scholarly journals Full arch zirconia monolithic with facial veneered ceramic - Clinical case

2019 ◽  
Vol 1 (1) ◽  
pp. 46-50
Keyword(s):  
Computer Aided Design ◽  
Clinical Case ◽  
Tetragonal Zirconia ◽  
High Strength ◽  
Tissue Response ◽  
Pubmed Database ◽  
First Choice ◽  
Computer Aided ◽  
Cad Cam ◽  
Soft Tissue Response

Purpose: The aim of this article is to evaluate the advantages of a full arch Zirconia monolithic restoration with facial veneered ceramics. Case report: Implant-supported, full-arch prostheses on a 53-year-old male, manufactured using a computer-aided design/computer-aided manufacturing system (CAD-CAM) zirconia framework facial veneered with feldspathic ceramic. Literature was searched to retrieve information about zirconia dental restorations and studies were critically analysed. PubMed database was searched for information. Conclusions: Our clinical case shows that zirconia veneered ceramics seems to be suitable for making it an ideal solution, such as biocompatibility, favourable soft tissue response, low thermal conductivity, resistance to corrosion. With the development of dental CAD/CAM systems, this high strength ceramic is becoming the first choice in treating aesthetic, implant cases, however there are few clinical reports supporting the use of monolithic Tetragonal Zirconia Polycrystal (TZP) for definitive prostheses. Long term clinical studies will be required to further evaluate this material and technique for continued use in implant restorations.

Effect of Cooling Rate below Ms Temperature on Hydrogen Embrittlement of TRIP-Aided Martensitic Steels

2021 ◽  
Vol 1016 ◽  
pp. 654-659
Author(s):  
Naoya Kakefuda ◽  
Shintaro Aizawa ◽  
Ryo Sakata ◽  
Junya Kobayashi ◽  
Goroh Itoh ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
Cooling Rate ◽  
Trip Steel ◽  
Retained Austenite ◽  
Volume Fraction ◽  
High Strength ◽  
Martensitic Steels ◽  
The Matrix ◽  
Embrittlement Resistance ◽  
Hydrogen Embrittlement Resistance

Low alloy TRIP steel is expected to be applied to automobile bodies because of its high strength, high ductility, and excellent impact properties and press formability. It has been reported that the low alloy TRIP steel of hydrogen embrittlement resistance is improved by utilizing the hydrogen storage characteristics of highly stable retained austenite. Therefore, for the purpose of increasing the volume fraction of retained austenite, it was produced at various cooling rates below the martensite transformation start temperature. As a result, the volume fraction of retained austenite increased, and then the effect of hydrogen embrittlement decreased. The matrix phase and retained austenite is refined with decrees of the cooling rate. It is considered that the size and surface area of the retained austenite also affected the improvement of hydrogen embrittlement resistance.

Sign in / Sign up

Export Citation Format

Share Document