Macrokinetic Analysis of Refractory Compound Synthesis Using the Electro-Thermal Explosion Method

Porous NiTi shape memory alloys were fabricated by thermal explosion method using different Ti and Ni powder as initial materials. The effect of process parameters including heating rate, and particle size of Ti on pore characteristic and phase composition was analyzed. Microstructure, phase composition, and mechanical properties were studied by SEM, XRD, and compression test, respectively. The mechanism of thermal explosion reaction was studied. The results show higher heating rate and smaller Ti particle size result in higher porosity and bigger pores. The thermal explosion reaction starts with the melting of a eutectic between β-Ti(Ni) and Ti2Ni and the main phases of as-reacted products are TiNi phase which are the desired phases. NiTi2 and TiNi3 phases are also present in small amounts. The content of TiNi phase increases with increasing heating rate or decreasing Ti particle size. The compressive strength and Young’s modulus of compacts decrease with the increase of the porosity.

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Properties of WC-Co Ceramic Coatings of Ultra-Fine Grains Prepared by Electro-Thermal Explosion Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.261-263.423 ◽

2004 ◽

Vol 261-263 ◽

pp. 423-428

Author(s):

Zong De Liu ◽

Kun Yang ◽

Shu Lin Bai ◽

Peng Duan

Keyword(s):

Shock Wave ◽

Thermal Explosion ◽

High Velocity ◽

Ceramic Coatings ◽

Bonding Layer ◽

Micro Hardness ◽

Measured Velocity ◽

Average Value ◽

Metallurgical Bonding ◽

Explosion Method

The high velocity spraying experiments for preparing WC-Co ceramic coatings were carried out by using an electro-thermal explosion directional spraying device. The transient parameters of both the discharge circuit and the voltage applied to the WC-Co sheet were measured. Velocity of the shock wave in the explosive spraying nozzle was approximately measured and that was described with a one-directional piston model. The velocity of molten particles of WC-Co ceramics was estimated to be about 3162m/s. The microstructures and micro-hardness of the WC-Co coating, the interface between the coating and substrate were analyzed in details. The visible WC grain diameter of the coating ranges from 70 to 350nm, and the average value is 195nm. A metallurgical bonding layer with a thickness of about 1 was found at the interface. The values of micro-hardness of the coating are 1-1.4 times of the original one, and the micro-hardness near the interface is much higher than that of the substrate

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Research on Precipitation Phenomenon of TiC and TiAl3 Particles in Aluminum Melt

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.602-604.612 ◽

2012 ◽

Vol 602-604 ◽

pp. 612-615

Author(s):

Wan Wu Ding ◽

Wen Jun Zhao ◽

Tian Dong Xia

Keyword(s):

Thermal Explosion ◽

Master Alloy ◽

Aluminum Melt ◽

Refining Effect ◽

Master Alloys ◽

Explosion Method ◽

Heat Preservation

The Al-TiC and Al-TiAl3 master alloys were prepared by thermal explosion method of aluminum melt, and the precipitation phenomenon of TiC and TiAl3 particles were studied in aluminum melt through separate addition of Al-TiC master alloy and composite addition of Al-TiC and Al-TiAl3 master alloys into aluminum melt. The results show that: When TiC exists in the aluminum melt separately, its speed of sedimentation is fast, and after a shorter time of heat preservation, a large amount of TiC will precipitate; when TiC and TiAl3 coexist in the aluminum melt, the speed of precipitation will become slow, and after a longer time of heat preservation, only a small amount of TiC will precipitate; and before TiAl3 settles to the bottom of the sample, it will dissolve. The attenuation of the refining effect of Al-TiC and Al-TiAl3 is mainly caused by the precipitation of TiC and the dissolution of TiAl3.

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Synthesis of Nanocrystalline Magnesium and Aluminum Diborides

Eurasian Chemico-Technological Journal ◽

10.18321/ectj664 ◽

2017 ◽

Vol 19 (3) ◽

pp. 209 ◽

Cited By ~ 1

Author(s):

M. Korchagin ◽

V. Zarko ◽

N. Bulina

Keyword(s):

Mechanical Activation ◽

Thermal Explosion ◽

Coherent Scattering ◽

High Energy ◽

High Mass ◽

Rocket Motors ◽

Explosion Products ◽

High Energy Material ◽

Explosion Method ◽

Solid Rocket

For obtaining MgB2 and AlB2 with nanometer size of coherent scattering area the technique based on the preliminary mechanical activation (MA) of initial reagents powder mixes and the subsequent reaction in the mode of the thermal explosion (TE) was used. The mentioned diborides are the promising compounds to use as a high-energy material in the ramjets and solid rocket motors because they possess very high mass- and volume-heat of combustion. Mostly, the diborides are produced under conditions of high temperatures and pressures. In this research a possibility has been explored of their producing by thermal explosion method when using preliminary mechanically activated components. The peculiarities of the technique to produce diborides are examined. Results of radiographic and electron microscope studies of the mixes of reagents after mechanical activation and of thermal explosion products are presented.

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