Synthesis and properties of 0.3%Y2O3/0.3%La2O3/0.3%Al2O3/Cu composite

2014 ◽  
Vol 21 (4) ◽  
pp. 517-520 ◽  
Author(s):  
Song Wang ◽  
Ming Xie ◽  
Jiming Zhang ◽  
Yongtai Chen

AbstractThe 0.3%Y2O3/0.3%La2O3/0.3%Al2O3/Cu composite was prepared by oxygen and nitrogen atomization spray deposition technique, internal oxidation, and then treated by annealing at different temperatures. Physical properties such as microstructures, fracture appearance, hardness, strength, electrical conductivity, and arc erosion surface of the composite were investigated. The experimental results show that with an increase in the annealing temperature, the grains of the composite grow up obviously and the electrical conductivity of the composite increases gradually, while the hardness and the tensile strength decrease. When the annealing temperature reaches 1000°C, the matrix grains begin to appear as annealing twins. The tensile fracture morphology of the composite that has been treated by annealing at 700°C for 2 h shows a huge number of large and deep dimples, in which the metallic oxide particles exist. The fracture mode of the composite is the microporous polycondensation plastic fracture. The arc erosion surface shows a large number of paste-like coagulum and bubbles.

2012 ◽  
Vol 236-237 ◽  
pp. 109-112
Author(s):  
Song Wang ◽  
Ming Xie

The 1.5%Y2O3/1.5%La2O3/Cu composite was prepared by oxygen and nitrogen atomization spray deposition technique and internal oxidation. The microstructures, hardness, strength, electrical conductivity and arc erosion surface of the composite were investigated by optical light microscope, scanning electron microscope, micro-hardness tester, tensile test and arc erosion experiment. The results show that, with the increasing of internal oxidation temperature, the grains of the composite grow up obviously. When the internal oxidation reaches to 1000°C, the matrix grains begin to appear annealing twins. The micro-hardness was 436HV, the ultimate tensile strength was 580MPa, yield tensile strength was 503MPa, elongation of alloy was 8.7% and the electrical conductivity was 87% IACS of the composite by internal oxidation at 1000°C for 2h.The arc erosion surface shows a large number of paste-like coagulum and bubbles. Introduction


2013 ◽  
Vol 750-752 ◽  
pp. 119-122 ◽  
Author(s):  
Xiao Ya Wang ◽  
Zhi Dong Xia ◽  
Zhe Li

This study was carried out to discuss the influence of curing temperature on the performance of conductive composites filled with nickel-coated graphite (NCG). The electrical conductivity, crosslink density, mechanical properties and tensile fracture morphology have been investigated. The results indicated that curing temperature had great impact on the electrical conductivity and mechanical properties. Voluem resistivity decreased from 43.1 to 0.08 ohm-cm at 125°C-205°C, and the reason was discussed in light of formation and break of the conductive network in the composites. The stability of SR-NCG cured at 165°C-205°C were also better than those cured at other curing temperature. Besides, tensile strength increased from 2.41 to 7.19Mpa at 125°C-225°C, elongation at break have a 56% increase, and Shore A hardness also incresed from 74 to 82.


2021 ◽  
Vol 871 ◽  
pp. 87-91
Author(s):  
Cai Tang ◽  
Jun Wen ◽  
Hui Ji Fan

The annealing process of an improved Q420 cold drawn tube was studied by using different annealing temperatures (430°C, 450°C, 470°C, 490°C and 510°C) with a same annealing holding time (3h). The effect of different annealing temperatures on the mechanical properties, microstructure and fracture features of the cold drawn tube was studied by means of tensile test, microstructure observation and scanning electron microscopy analysis. The results show that, annealing temperature has great influence on the strength and plasticity of the cold drawn tube. When the annealing temperature increased to 450°C, banded microstructure was mitigated and the pearlite is relatively dispersed. The tensile fracture morphology under the annealing temperature of 450°C has more dimples and deeper bremsstrahlung than other annealing temperatures. The best annealing process of the cold drawn tube was 450°C×3h. Under this annealing process, the cold drawn tube with good strength and toughness can be obtained.


2017 ◽  
Vol 909 ◽  
pp. 127-132 ◽  
Author(s):  
Hyung Jin Kim ◽  
Sun Ig Hong

In this study, electro nickel coating was applied and its effect on the electrical conductivity and mechanical properties was investigated in Cu/Ni/Al/Ni/Cu clad composite after annealing at various temperature. After annealing at 300OC for 3hrs, the interface reaction layer at the Cu/Al interface was observed to be 3μm and no reaction layer was observed at the Ni/Al interface. After annealing above 400OC for 3hrs, the interface reaction layer at the Cu/Al interface in the absence of Ni layer was observed to grow more rapidly with increase of annealing temperature compared to that at the Ni/Al interface. The electrical conductivity increased after annealing up to 300OC for 3 hrs. possibly because of enhanced interface bonding and the recovery in the matrix. However, it was deteriorated after annealing above 400OC for 3 hrs. because of the formation of interface intermetallic. The more localized bending in the as-roll-bonded clad composite and that annealed at 200°C can be attributed to the near-zero and negative hardening rate in bending over the whole displacement. In this case, once bending occurs, bending continue to occur in the localized region because the work hardening due to the localized bending is negligible, leading to the localized fracture.


2014 ◽  
Vol 1063 ◽  
pp. 112-119
Author(s):  
You Zhen Fang

Resistance spot welding of BTR165 was applied to study property of its joint by using power-frequency alternating current welding equipments. The tension strength, hardness distribution, microstructure and tensile fracture appearance were analyzed. The test results show that the hot-stamped steel has good weldability and could obtain better performance by optimizing technology. The microstructure of spot welded metal is martensite (M), tensile failure mode is button pull-out fracture, The fracture morphology has plastic dimple characteristic.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 966
Author(s):  
Qingle Tian ◽  
Kai Deng ◽  
Zhishuai Xu ◽  
Ke Han ◽  
Hongxing Zheng

Using a centrifugal casting method, along with deformation and aging, we produced a high-strength, low-anisotropy Al-Li plate. The electron probe microanalysis, transmission electron microscope, differential scanning calorimetry, and X-ray diffraction were used to clarify the evolution of strengthening phases. Experimental results showed that centrifugal-cast Al-Li plate consisted of intragrain δ′—(Al,Cu)3Li precipitate and interdendritic θ′—Al2Cu particles. After cold-rolling to a reduction ratio of 60% and annealing at 800 K for 90 min, both primary θ′ and δ′ were dissolved in solid solution. Aging at 438 K for 60 h led to the formation of two kinds of precipitates (needle-like T1—Al2CuLi and spherical δ′ in two sizes), which acted as the main strengthening phases. The average values of ultimate tensile strength and yield strength for the anneal-aged plate reached 496 MPa and 408 MPa, with a total elongation of 3.9%. The anneal-aged plate showed mechanical anisotropy of less than 5%. The tensile fracture morphology indicated a typical intergranular fracture mode.


2007 ◽  
Vol 1044 ◽  
Author(s):  
Mi-kyung Han ◽  
Huijun Kong ◽  
Ctirad Uher ◽  
Mercouri G Kanatzidis

AbstractWe performed comparative investigations of the Ag1-xPb18MTe20 (M = Bi, Sb) (x = 0, 0.14, 0.3) system to better understand the roles of Sb and Bi on the thermoelectric properties. In both systems, the electrical conductivity nearly keeps the same values, while the Seebeck coefficient decreases dramatically in going from Sb to Bi. Compared to the lattice thermal conductivity of PbTe, that of AgPb18BiTe20 is substantially reduced. The lattice thermal conductivity of the Bi analog, however, is higher than that of AgPb18SbTe20 and this is attributed largely to the decrease in the degree of mass fluctuation between the nanostructures and the matrix (for the Bi analog). As a result the dimensionless figure of merit ZT of Ag1-xPb18MTe20 (M = Bi) is found to be smaller than that of Ag1-xPb18MTe20 (M = Sb).


2019 ◽  
Vol 8 (1) ◽  
pp. 619-627 ◽  
Author(s):  
Shaolin Li ◽  
Xiuhua Guo ◽  
Shengli Zhang ◽  
Jiang Feng ◽  
Kexing Song ◽  
...  

AbstractArc erosion behaviors of TiB2/Cu composites with single-scale and dual-scale TiB2 particles fabricated by powder metallurgy were studied. It was revealed that the dual-scale TiB2/Cu composites had fewer structure defects compared with the single-scale TiB2/Cu composites, and TiB2 particles with different size were uniformly distributed in the copper matrix. When the ratio of 2 μm over 50 μm TiB2 particles is 1:2, the density of TiB2/Cu composite is 98.5% and shows best mechanical and thermal properties. The arc duration and energy of TiB2/Cu composites increase with the increase of electric current in contact material testing. Compared with the single-scale TiB2/Cu composites, the arc erosion of dual-scale TiB2/Cu composite with 2 μm+50 μm (1:2) TiB2 was slighter. The anode bulge area and cathode erosion pit of dual-scale TiB2/Cu composite was smaller. The dual-scale TiB2 particles optimize the microstructure and thermal stability of the composite, which is conducive to alleviating arc erosion. The synergistic effect of different sized TiB2 particles in the matrix improved the arc erosion resistance of TiB2/Cu composite during arcing.


2017 ◽  
Vol 37 (6) ◽  
pp. 547-557 ◽  
Author(s):  
Sekaran Sathees Kumar ◽  
Ganesan Kanagaraj

Abstract In this paper, the combined effect of different weight percentages of silicon carbide (SiC) and graphite (Gr) reinforcement on the mechanical properties of polyamide (PA6) composite is studied. Test specimens of pure PA6, 85 wt% PA6+10 wt% SiC+5 wt% Gr and 85 wt% PA6+5 wt% SiC+10 wt% Gr are prepared using an injection molding machine. The tensile, impact, hardness, morphology and thermal properties of the injection molded composites were investigated. The obtained results showed that mechanical properties, such as tensile and impact strength and modulus of the PA6 composites, were significantly higher than the pure PA6, and hybridization with silicon carbide and graphite further enhanced the performance properties, as well as the thermal resistance of the composites. The tensile fracture morphology and the characterization of PA6 polymer composites were observed by scanning electron microscope (SEM) and Fourier transform infrared spectroscopic methods. SEM observation of the fracture surfaces showed the fine dispersion of SiC and Gr for strong interfacial adhesion between fibers and matrix. The individual and combined reinforcing effects of silicon carbide and graphite on the mechanical properties of PA6 hybrid composites were compared and interpreted in this study. Improved mechanical properties were observed by the addition of small amount of SiC and Gr concurrently reinforced with the pure PA6. Finally, thermogravimetric analysis showed that the heat resistance of the composites tended to increase with increasing silicon carbide and graphite content simultaneously.


2008 ◽  
Vol 57 (6) ◽  
pp. 3840
Author(s):  
Yang Feng-Xia ◽  
Zhang Duan-Ming ◽  
Deng Zong-Wei ◽  
Jiang Sheng-Lin ◽  
Xu Jie ◽  
...  

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