Mechanical Properties Of Quasicrystal Dispersed Al-Li-Cu Alloy

1998 ◽  
Vol 553 ◽  
Author(s):  
T. Okada ◽  
T. Nakamura ◽  
K Mitsugi ◽  
K Kozawa ◽  
T Matumura ◽  
...  

AbstractTo apply the ductile structural materials, the quasicrystal dispersion in aluminum alloys is one of effective methods. We have investigated mechanical properties of quasicrystal dispersed Al- Li-Cu alloy prepared by the twin-type piston anvil apparatus. The slow cooled samples are hard and ductile. The evaluated values of brittleness are from 6.0 to 14 erg for Ef, from 0.52 to 0.73MNm−3/2 for K1c and from 5.5 to 7.7 Nm−1 for Gic for the fastest and slowest cooled samples, respectively. The hardness of the quasicrystal dispersed Al-Li-Cu alloy is higher than that of the other commercial aluminum alloys. Based on the relationship between Vickers hardness and proof stress of aluminum alloys, we estimate the specific strength of Al-Li-Cu quasicrystal alloy. The maximum value is the higher than that of Ti alloys.

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Jiaheng Li ◽  
Yingbo Zhang ◽  
Xinyu Cao ◽  
Qi Zeng ◽  
Ye Zhuang ◽  
...  

Abstract Aluminum alloys are attractive for a number of applications due to their high specific strength, and developing new compositions is a major goal in the structural materials community. Here, we investigate the Al-Zn-Mg-Cu alloy system (7xxx series) by machine learning-based composition and process optimization. The discovered optimized alloy is compositionally lean with a high ultimate tensile strength of 952 MPa and 6.3% elongation following a cost-effective processing route. We find that the Al8Cu4Y phase in wrought 7xxx-T6 alloys exists in the form of a nanoscale network structure along sub-grain boundaries besides the common irregular-shaped particles. Our study demonstrates the feasibility of using machine learning to search for 7xxx alloys with good mechanical performance.


2012 ◽  
Vol 512-515 ◽  
pp. 377-381 ◽  
Author(s):  
Jin Rong Lu ◽  
Yang Zhou ◽  
Yong Zheng ◽  
Shi Bo Li ◽  
Zhen Ying Huang ◽  
...  

In this paper, a new type of Ti3SiC2/Cu composites with the volume fractions of 30% Ti3SiC2 particle was prepared by hot pressing and vacuum sintering respectively. The effects of sintering temperature and holding time on the density, resistance and Vickers hardness of Cu-30vol%Ti3SiC2 composite were investigated. The results show that the mechanical properties of the composites prepared by hot pressing are better than that prepared by vacuum sintering. The relative densities of Cu-30vol% Ti3SiC2 composites are rather high in suitable sintering conditions. It achieved 100% for the composites prepared by hot pressing at 930°C for 2h, and 98.4% for the composites prepared by vacuum sintering at 1250°C for 1h. At the same time, the maximum Vickers hardness reached 1735MPa at 900°C by hot pressing. The resistance and Vickers hardness of the composites decreased with an increase in sintering temperature, whereas the density increased. Scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS) were used to observe the microstructure of the composites. The relationship between microstructure and mechanical properties was discussed.


2019 ◽  
Vol 950 ◽  
pp. 75-79
Author(s):  
Zhen Hai Xu ◽  
Chao Ran Ding ◽  
De Bin Shan

With the ever-increasing concern about the energy and environment crises, aluminum alloys are becoming increasingly desirable in the automotive, aerospace, construction and other related industries due to their high specific strength. Various heat-treatment–stamping integrated techniques have been invented to address the formability challenge of aluminum alloy sheets. Electric field affects the heat treatment process of aluminum alloys. In this paper, a device for application of electric field during the heat treatment was developed. The maximum dimensions of specimen are determined via observing the distortion of metal sheets after quenching in cool water. The high-temperature resistant pure nickel wire gains a high-voltage proof performance by wearing bowl-shaped porcelain tubes, and is used to connect electrodes to power supply. The high-voltage resistant mica plates are bolted together to fill the gap between the specimen and electrode. This device was then used in a common commercial furnace to study the effect of electric field applied during the heat treatment on mechanical properties of AA 6082 sheets. It is found that electric field could enhance mechanical properties of AA 6082. The application of electric field has a potential to lower the cost of heat-treatment–stamping integrated techniques.


2006 ◽  
Vol 503-504 ◽  
pp. 627-632 ◽  
Author(s):  
Koichi Nakashima ◽  
M. Suzuki ◽  
Y. Futamura ◽  
Toshihiro Tsuchiyama ◽  
Setsuo Takaki

The limit of dislocation density was investigated by means of mechanical milling (MM) treatment of an iron powder. Mechanical milling enabled an ultimate severe deformation of iron powder particles and dislocation density in the MM iron powder showed the clear saturation at around the value of 1016m-2. On the other hand, the relation between hardness and dislocation density was examined in cold-rolled iron sheets, and the linear Bailey-Hirsch relationship; HV[GPa]=0.7+3×10-8ρ1/2 was obtained in the dislocation density region up to 3×1015m-2. Extrapolation of the Bailey-Hirsch relationship indicated that the dislocation strengthening should be limited to about 3.7GPa in Vickers hardness which corresponds to about 1.1GPa in 0.2% proof stress.


1973 ◽  
Vol 15 (1) ◽  
pp. 53-60 ◽  
Author(s):  
R. D. Adams ◽  
M. A. O. Fox

Cast irons were produced with variations in the quantity and shape of the free graphite inclusions and in the matrix structure to investigate the relationship between the shear, compressive and tensile mechanical properties. Differences were observed which may have a significant effect on design criteria for cast irons. For example, the ratio of shear to tensile strengths decreased from about 1·25 to 0·577 and the ratio of 0·1 per cent proof stress in compression to that in tension decreased from approximately 2 to 11 as the tensile strength (and ductility) were increased.


2020 ◽  
Vol 2 (2) ◽  
pp. 147-155
Author(s):  
Ibrahim Mohammed Danmalam ◽  
Ibrahim Bulus

Magnesium-zinc-sulfophosphate glasses with various concentration of Silver nanoparticles (AgNPs) of molar composition 63.5P2O5–20MgO –15ZnSO4–1.5Eu2O3 –yAgNps (y = 0.0, 0.1, 0.3, 0.5, 0.7,0.9 and 1.1 g in excess) were prepared via melt-quenching method.  As-synthesized glasses were characterized at room temperature to determine the relationship between structural and mechanical properties. Densities of glasses were increased from 3.0720 to 4.3304 g.cm-3 with increase in AgNPs embedding levels, suggesting the network shrinkages and enhanced compactness. The Young’s, shear and bulk modulus of glasses were observed to enhance with the increase in AgNPs contents. The Poisson’s ratio of the studied glasses was increased from (0.0978 to 0.1416) while the values of both Vickers hardness (from 0.0658 to 0. 0.0682 GPa) as well as  (from 0.8350 to 0.8916) were increased. The proposed glass composition may be useful for the development of hard surface engineering.


2020 ◽  
Vol 4 (1) ◽  
pp. 17 ◽  
Author(s):  
Akihiro Iwase ◽  
Fuminobu Hori

When materials are irradiated with high-energy ions, their energies are transferred to electrons and atoms in materials, and the lattice structures of the materials are largely changed to metastable or non-thermal equilibrium states, causing the modification of several physical properties. There are two processes for the material modification by ion irradiation; one is “the irradiation-enhanced process”, and the other is “the irradiation-induced process”. In this review, two kinds of recent results for the microstructural changes and the modifications of mechanical properties will be summarized: one is the hardness modification of dilute aluminum alloys, which is a result of the irradiation-enhanced process, and the other is the hardness modification of Ni-based intermetallic compounds as a result of the irradiation-induced process. The effect of the subsequent thermal treatment on the microstructures and the hardness for ion-irradiated dilute aluminum alloys is quite different from that for Ni-based intermetallic compounds. This result reflects the difference between the irradiation-enhanced process and the irradiation-induced process. Finally, possibilities of the ion irradiation and subsequent thermal treatment to industrial applications will also be discussed.


Parasitology ◽  
1986 ◽  
Vol 92 (1) ◽  
pp. 209-217 ◽  
Author(s):  
Akweley Annan ◽  
D. W. T. Crompton ◽  
D. E. Walters ◽  
S. E. Arnold

SUMMARYEvidence for the presence of 11 intestinal parasites in pre-school children from 4 rural villages in Ghana was obtained from an examination of stool samples. Striking differences were detected between the prevalence of some of the 6 common infections in the 4 villages. The prevalance of Ascaris lumbricoides varied from about 76% in one village (Oshiyie, coastal savanna) to apparently 0% in another (Akuma, forest zone). No differences in prevalence for any infection were observed to be sex dependent. Investigation of the relationship between age of the children and prevalance showed that the degree of prevalence of both A. lumbricoides and Trichuris trichiura had essentially levelled off by the time the children were 4 years old. There was no evidence to suggest that the prevalence of either Entamoeba sp. or spp. or hookworm was approaching a maximum value, even in the oldest children. These trends applied across the villages regardless of the differences in prevalence values for the infections. On average, the children of Oshiyie were found to harbour twice as many infections as the children of the other villages. The investigation of the prevalence data revealed evidence of associations between pairs of infections, particularly those involving hookworm and T. trichiura.


2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
M. E. Kassner ◽  
P. Geantil ◽  
X. Li

The purpose of this study is to investigate the quench sensitivity of the mechanical properties of 6061 and 6069 aluminum alloys. The relationship between mechanical properties and quench delay time at various temperatures between 200–500°C was determined. It was concluded that the 6069-T6 was somewhat more quench sensitive than 6061, which may be consistent with the composition difference. This study also provides increased data on the quench sensitivity of the traditional alloy, 6061-T6.


2014 ◽  
Vol 67 (2) ◽  
pp. 173-179 ◽  
Author(s):  
Angela de Jesus Vasconcelos ◽  
Cibele Vieira Arão da Silva ◽  
Antonio Luciano Seabra Moreira ◽  
Maria Adrina Paixão de Sousa da Silva ◽  
Otávio Fernandes Lima da Rocha

Al-Sn alloys are widely used in tribological applications. In this study, thermal, microstructural and microhardness (HV) analysis were carried out with an Al-5.5wt.%Sn alloy ingot produced by horizontal directional transient solidification. The main parameters analyzed include the growth rate (V L) and cooling rate (T R).These thermal parameters play a key role in the microstructural formation. The dendritic microstructure has been characterized by primary dendritic arm spacing (λ1) which was experimentally determined and correlated with V L, and T R. The behavior presented by the Al-5.5wt.%Sn alloy during solidification was similar to that of other aluminum alloys, i.e., the dendritic network became coarser with decreasing cooling rates, indicating that the immiscibility between aluminum and tin does not have a significant effect on the relationship between primary dendritic arm spacing and the cooling rate. The dependence of the microhardness on V L, T R and λ1 was also analyzed. It was found that for increasing values of T R, the values of HV decrease. On the other hand, the values of HV increase with increasing values of λ1.


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