Influence of Al–Al2O3 composite powder on the matrix microstructure in composite casts

2002 ◽  
Vol 49 (2) ◽  
pp. 165-169 ◽  
Author(s):  
Anita Olszówka-Myalska ◽  
Janusz Szala ◽  
Józef Śleziona ◽  
Bolesław Formanek ◽  
Jerzy Myalski
Author(s):  
Qilong Chen ◽  
Tianbin Zhu ◽  
Yawei Li ◽  
Yong Cheng ◽  
Ning Liao ◽  
...  

Wear ◽  
2021 ◽  
Vol 472-473 ◽  
pp. 203608
Author(s):  
Yanliang Yi ◽  
Qiang Li ◽  
Shaolei Long ◽  
Zhen Lv ◽  
Shuangjian Li ◽  
...  

2021 ◽  
Vol 4 (12(112)) ◽  
pp. 47-52
Author(s):  
Raad Mohammed Abed ◽  
Ali Yousuf Khenyab ◽  
Hussain Jasim M. Alalkawi

Aluminum is expected to remain the core material for many critical applications such as aircraft and automobiles. This is due to the high resistance to different environmental conditions, desired and manageable mechanical properties, as well as high fatigue resistance. Aluminum nanocomposites such as AA6061/Al2O3 can be made in many ways using a liquid metallurgy method. The main challenges for this method in the production of nanocomposites are the difficulties of achieving a uniform distribution of reinforcing materials and possible chemical reactions between the reinforcing material and the matrix. For structural applications exclusive to aerospace sectors. The growing cost-effective nanocomposites mass production technology with essential operational and geometric flexibility is a big challenge all the time. Each method of preparing AA6061/Al2O3 nanocomposites can provide different mechanical properties. In the present study, nine nanocomposites were prepared at three stirring temperatures (800, 850, and 900 °C) with the level of Al2O3 addition of 0, 5, 7, and 9 wt %. The results of tensile, hardness and fatigue tests revealed that the composite including 9 wt % Al2O3 with 850 °C stirring temperatures has the best properties. It was also revealed that the 850 °C stirring temperature (ST) with 9 wt % Al2O3 composite provide an increase in tensile strength, VHN and reduction in ductility by 20 %, 16 % and 36.8 % respectively, compared to zero-nano. Also, the fatigue life at the 90 MPa stress level increased by 17.4 % in comparison with 9 wt % nanocomposite at 800 °C (ST). Uniform distributions were observed for all nine microstructure compositions.


Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 878 ◽  
Author(s):  
Íris Carneiro ◽  
Filomena Viana ◽  
Manuel F. Vieira ◽  
José V. Fernandes ◽  
Sónia Simões

The development of metal nanocomposites reinforced by carbon nanotubes (CNTs) remains a focus of the scientific community due to the growing need to produce lightweight advanced materials with unique mechanical properties. However, for the successful production of these nanocomposites, there is a need to consolidate knowledge about how reinforcement influences the matrix microstructure and which are the strengthening mechanisms promoting the best properties. In this context, this investigation focuses on the study of the reinforcement effect on the microstructure of an Ni-CNT nanocomposites produced by powder metallurgy. The microstructural evolution was analysed by electron backscattered diffraction (EBSD). The EBSD results revealed that the dispersion/mixing and pressing processes induce plastic deformation in the as-received powders. The dislocation structures produced in those initial steps are partially eliminated in the sintering process due to the activation of recovery and recrystallization mechanisms. However, the presence of CNTs in the matrix has a significant effect on the dislocation annihilation, thus reducing the recovery of the dislocation structures.


2016 ◽  
Vol 27 (2) ◽  
pp. 711-716 ◽  
Author(s):  
Chunlei Yan ◽  
Rongjun Liu ◽  
Changrui Zhang ◽  
Yingbin Cao ◽  
Xianhai Long

2011 ◽  
Vol 672 ◽  
pp. 133-136
Author(s):  
Nicolaie Jumate ◽  
Ioan Vida-Simiti ◽  
Dorel Nemeş ◽  
György Thalmaier ◽  
Niculina Sechel ◽  
...  

The paper presents a preliminary study on the obtaining of a composite powder by an electrolytic method. The composite powder particles are composed of iron nickel alloy that represents the matrix of the composite, and titanium carbide as the reinforcement. The matrix was obtained by electrolytic co-deposition from pure iron and nickel, in form of consumable electrodes. The titanium carbide powder is in suspension in the electrolyte. By the migration of metallic ions towards the cathode, the iron- nickel alloy is formed and, by simultaneously driving the carbide particles found in the electrolyte onto the cathode, the composite powder is obtained. The resulted composite powders were characterized by optical and electron microscopy. The influence of obtaining conditions over the morphology and structure of composite powders is emphased.


2007 ◽  
Vol 345-346 ◽  
pp. 545-548
Author(s):  
Satoshi Emura ◽  
Masuo Hagiwara

A TiB particulate-reinforced Ti-22Al-27Nb (mol%) alloy, based on the orthorhombic intermetallic phase, was prepared using gas atomization powder metallurgy method. In the as-atomized condition, extremely fine TiB particulates of less than 1-μm diameter and 5-μm length were dispersed in the matrix. After annealing heat treatment (heat treated at 1423 K with subsequent furnace cooling), this composite exhibited a lamellar matrix microstructure and showed better creep properties than a composite produced using conventional ingot metallurgy method, with coarse TiB particulates of 5-μm diameter and 40-μm length. Coarsening of the matrix microstructure and growth of TiB particulates occurred after annealing heat treatment at higher temperature (ca. 1473 K). Creep-resistance improvement was also observed, which seemed to be mainly attribute to the effect of the matrix microstructure. From measurements of stress components and activation energy, all composites showed an identical creep mechanism: dislocation-controlled creep.


2010 ◽  
Vol 457 ◽  
pp. 279-284 ◽  
Author(s):  
Masahito Tanaka ◽  
Kazumichi Shimizu ◽  
Daijiro Ito ◽  
Toru Noguchi

The purpose of this study is to investigate the fatigue characteristic and fatigue fracture mechanism of the high V-Cr-Ni spheroidal carbide cast iron (SCI-VCrNi) with spheroidal vanadium carbide (VC) dispersed within austenitic stainless matrix microstructure. The SCI-VCrNi that has high hardness was developed by 10mass%V adding to 18-8 stainless steel with spheroidal VC is distributed in the matrix. Firstly from the plane bending, the fatigue limit σw has been found to the 358MPa of SCI-VCrNi. Secondly, fracture surface observations were performed to clarify the fatigue mechanism of SCI-VCrNi. The fracture surface of SCI-VCrNi was so rough that the beach mark could not be observed. So, SEM was employed to observe, the fatigue fracture surface which showed a particular fatigue pattern. Also, many fracture cracks of VC were observed. In addition, the secondary cracks are shown at the interface between VC and the matrix. It can be suggested that the bondability between VC and the matrix is strong, and therefore, the propagation of cracks was delayed by the breakage of VC.


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