scholarly journals Fabrication of In-Situ Intermetallic Compound Dispersed Aluminum Matrix Composites by Addition of Metal Powders

2006 ◽  
Vol 47 (12) ◽  
pp. 2972-2979 ◽  
Author(s):  
Mitsuaki Matsumuro ◽  
Tadashi Kitsudo
2011 ◽  
Vol 284-286 ◽  
pp. 2280-2283 ◽  
Author(s):  
Gui Rong Li ◽  
Xun Yin Zhang ◽  
Yi Nan Zhao ◽  
Fei Yuan ◽  
Ting Wang Zhang ◽  
...  

The K2TiF6,K2ZrF6powder and aluminum were selected as the raw materials to in situ synthesize the particulates reinforced aluminum matrix composites. During the fabrication process the electromagnetic field was imposed. The atomic ratio of Al/Ti/Zr in the particulates is determined as 3/0.4/0.6. The Al3Ti0.4Zr0.6is a new kind of intermetallic compound, some properties of which fall in between those of Al3Ti and Al3Zr. Electromagnetic field plays an important part in fining particles and promoting their uniform distribution. When the electromagnetic induced intensity is 0.05T the particles have 0.5-2μm average size and uniform distribution in matrix. The crystal grains of matrix resemble equiaxed ones. The average size of grains are nearly 100μm, 50μm and 25μm when the electromagnetic induced intensities are 0, 0.025T and 0.05T seperately.


2018 ◽  
Vol 25 (07) ◽  
pp. 1950010
Author(s):  
MORTEZA SHAMANIAN ◽  
EBRAHIM BAHRAMI ◽  
HOSSEIN EDRIS ◽  
MOHAMAD REZA NASRESFAHANI

In this research, in situ ultrafine Al–Ni intermetallics were fabricated as reinforcement in the aluminum matrix by Friction Stir Process (FSP). Activated and non-activated powders were used as reinforcement agents. The FSP was performed under the rotating speed of 1250[Formula: see text]rpm, traverse speed of 24, 32, 44 and 62[Formula: see text]mm/min to fabricate composite. Scanning Electron Microscopy, Optical Microscopy and XRD patterns were used for microstructural observations and phase analysis of fabricated composite, respectively. In this study, it is shown that by using nickel powder (non-activated), only Al3Ni compound is formed during FSP. But in the fabricated composite with activated powder because of increasing grain boundaries and dislocation during ball milling, Al3Ni2, Al3Ni and AlNi may be formed. Using activated powder creates ultrafine intermetallic reinforcements and causes more uniform distribution of intermetallics.


2015 ◽  
Vol 787 ◽  
pp. 583-587 ◽  
Author(s):  
V. Mohanavel ◽  
K. Rajan ◽  
K.R. Senthil Kumar

In the present study, an aluminum alloy AA6351 was reinforced with different percentages (1, 3 and 5 wt %) of TiB2 particles and they were successfully fabricated by in situ reaction of halide salts, potassium hexafluoro-titanate and potassium tetrafluoro-borate, with aluminium melt. Tensile strength, yield strength and hardness of the composite were investigated. In situ reaction between the inorganic salts K2TiF6 and KBF4 to molten aluminum leads to the formation of TiB2 particles. The prepared aluminum matrix composites were characterized using X-ray diffraction and scanning electron microscope. Scanning electron micrographs revealed a uniform dispersal of TiB2 particles in the aluminum matrix. The results obtained indicate that the hardness and tensile strength were increased with an increase in weight percentages of TiB2 contents.


1999 ◽  
Vol 14 (11) ◽  
pp. 4246-4250
Author(s):  
H. J. Brinkman ◽  
J. Duszczyk ◽  
L. Katgerman

A method is described for the production of dense aluminum matrix composites from elemental powders in one processing step by reactive hot pressing (RHP). It encompasses both the exothermic conversion of reactants to composite product and the following hot compaction of the porous composite product. The RHP method described in this paper takes into account the gas evolution accompanying the exothermic process, ensures complete conversion of reactants, and avoids adverse reactions between aluminum matrix and graphite tooling material. In situ sample temperature measurements enable proper process control, in particular the timing of the full densification step of the hot reaction product.


2021 ◽  
Vol 87 (5) ◽  
pp. 34-42
Author(s):  
N. B. Podymova ◽  
I. E. Kalashnikov ◽  
L. I. Kobeleva

One of the most critical manufacturing defects of cast metal-matrix composites is a non-uniform porosity distribution over the composite volume. Unevenness of the distribution leads not only to local softening, but also plays a key role in the evolution of the damage process under the external loads. The goal of the study is to apply a new laser-ultrasonic method to in-situ study of a local porosity in reactive cast aluminum-matrix composites. The proposed method is based on statistical analysis of the amplitude distribution of backscattered broadband pulses of longitudinal ultrasonic waves in the studied materials. Laser excitation and piezoelectric detection of ultrasound were carried out using a laser-ultrasonic transducer. Two series of reactive cast aluminum-matrix composites were analyzed: reinforced by in situ synthesized Al3Ti intermetallic particles in different volume concentrations and by Al3Ti added with synthetic diamond nanoparticles. It is shown that for both series of the composites, the amplitude distribution of backscattered ultrasonic pulses is approximated by the Gaussian probability distribution applicable for statistics of large number of independent random variables. The empirical dependence of the half-width of this distribution on the local porosity in composites of two series is approximated by the same nearly linear function regardless of the size and fraction of reinforcing particles. This function was used to derive the formula for calculation of the local porosity in the studied composites. The developed technique seems to be promising in revealing potentially dangerous domains with high porosity in reactive-cast metal-matrix composites.


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