Search results

Introduction Diamond tools are used in the cutting, grinding and polishing for hard and brittle materials such as ceramic, glass, granite and so on.
After the SHS reactions, the samples were examined by XRD (Philip X-pert), SEM (Philip XL-30FEG).The rough grinding test was carried out on the vertical dill to grind the granite for 15min.
It was an ideal form of diamond tool for grinding.
The grinding sample had been tried to grinding granite for 15min.
Ni-Al-diamond composite fabricated by induction heating had ideal morphology and microstructure as diamond tools for grinding.

The Effects of Particle Size and Morphology of Raw Materials on the Properties of MoSi2 Synthesized by SHS Zhou Ying1,a，Wei Caili1,b, Ye Guotian1,c, Liu Chenyong2,a 1Departiment of Materials Science and Engineering, Zheng Zhou University, Zhengzhou 450001, China 2 Departiment of Staff, Air Defence College, Zhengzhou 450052, China a zhouying@zzu.edu.cn,b weicaili1986@126.com, c gtye@zzu.edu.cn Keyword: MoSi2, SHS, particle size, morphology Abstract.
In this work, the influences of the particle size and morphology of raw materials on the formation of MoSi2 by self-propagating high-temperature synthesis (SHS) were investigated.
The SHS technique has been generated great interests due to low energy requirement, short processing time, simplicity of facilities, high purity products.
However, the effects of the particle size and morphology of raw materials on the formation of MoSi2 synthesized by SHS were not well known yet.
With grinding for 10h, the morphology of Mo powders changed slightly, which was as same as Mo powders after grinding for 5h.

MA-SHS of ZrC and ZrB2 in Air from The Zr/B/C Powder Mixtures T.
A 25 ml jar and seven balls of 12 mm in diameter of tungsten carbide were used for grinding.
Results and Discussion Fig.1 shows the X-ray diffraction patterns of the samples of Zr/B/C=2/2/1 ground for 0~45 min and the product obtained in MA-SHS after grinding of 60 min.
The α-Zr peaks apparently decreased in intensity and broadened with increasing grinding time and the 002 peak of graphite disappeared after the grinding of 30 min.
In the former, the sample self-ignited in air after the grinding of 45 min and formed ZrC, while in the latter, it did not self-ignite even after the grinding of 120 min.

But in super-high speed(SHS) grinding process, the number of particles involved in interaction is much more than that in common grinding, which makes the surface performance become better after grinding in theory because of more particles joining in machining.
The surface quality has been improved in theory based on the number of cutting from effective particles in SHSP grinding while grinding in the same wheel speed and other factors compared to SHS grinding.
The roughness is about 2.4 µm shown in Fig.8(a) got by SHS grinding, and by contrast that is about 1.7 µm shown in Fig.8(b) got by SHSP grinding, which provides the evidences that the technology of SPHP grinding is better than no swivel angle exists.
All others parameters in Fig.8(b) to describe the surface is smaller than SHS grinding.
The final conclusions are shown as follows: As the swivel angle is brought in the SHS grinding, the contact area between the wheel and the workpiece has been changed, which is affected by grinding parameters.

Based on SHS reactive flame spray technology, Al2O3 multiphase ceramics coatings were produced.
Compared with the traditional flame spray, SHS RFS has many new properties [4].
After being dried at 150°C, the Al and CuO powders were sifted, then mixed in the ball-grinding machine in proper proportion, and then prepared into the agglomerated particles in proper size range.
Before spraying the substrate was cleaned by the grinding wheel to remove the rust, then the surface was roughened and preheated.
It can be concluded that the SHS RFS process is far from equilibrium.

This paper describes a method of compaction of SHS-derived γ-alon powder using the hydrolysis reaction of aluminum nitride, which is one of the products of SHS synthesis.
Application of the above-mentioned high-temperature synthesis usually resulting in strong aggregation of powders and thus they need extensive grinding before sintering.
Obtaining sintered materials with minimum porosity from such powders requires intense grinding of synthesis products, and then hot pressing (HP or HIP) [7].
As far as the technology of refractory materials is concerned, where such material cannot, or sometimes should not, be of an extremely high density, powders produced by SHS may be active enough during sintering that they do not require long and intense grinding.
Lis, Alon-based materials prepared by SHS technique, J.

Fabrication of SPS Compacts from Ta, Hf-Containing ZrB2-ZrC Powder Mixtures Synthesized by the MA-SHS in Air Process T.
A 25 ml jar and seven balls of 12 mm in diameter of tungsten carbide were used for grinding.
The grinding was interrupted every 15 min, and the sample was scraped from the balls and the sidewalls of the jar and then reloaded to continue grinding.
After grinding, the ground sample was transferred into a graphite crucible (inner diameter of 30 mm and depth of 40 mm) and exposed to air.
After the grinding of 45~60 min, all the powder mixtures of (Ta or Hf+Zr)/B/C=2/2/1 self-ignited in air and the subsequent exothermic reaction violently occurred evolving white heat.

SHS Ferroaluminum Obtained from the Disperse Waste of Engineering G.N.
The SHS process is initiated in the mixture composed of the dispersed waste engineering.
In this research we obtain ferroaluminum FA30 from dispersed engineering waste, such as big house dust, scale of forging and heat treatment plants, sludge from the electrochemical and electrical treatment, sputtering, grinding, milling operations, sharpening and other types of metal processing by cutting.
Therefore, SHS ferroaluminum is very clean in respect of these impurities. 2.
Merzhanov, SHS, Physical chemistry, Chemistry, Moscow, 1983

Ferrous-tungsten powders were obtained by crushing large lumps into small pieces, and then grinding and screening them into fin powders.
Composition of the SHS reactant is listed in Tab.1, which is referred to literature [6].
These powders were weighted and put into a small laboratory grinding machine mixing for 60 minutes with the powder to grinding ball ratio 3 to 1.
Small zircon balls were employed for the grinding.
(3) The addition of certain amount of Fe as coolants in SHS reactants is necessary.

The addition of ferrotitanium into the SHS reactants aims to bring large amounts of Fe to act as the SHS diluent.
Ferrotitanium powders were obtained by crushing large lumps into small pieces, and then grinding and screening.
Table 1 Composition of the SHS Reactants (wt%) ferrotitanium metal titanium B4C Borax SHS1 15% 55% 27% 3 SHS 2 30% 47% 20% 3 SHS 3 45% 35% 17% 3 These powders were weighted and put into a small laboratory grinding machine to be mixed for 60 minutes with a ratio of the powder to grinding ball 3:1.
Small zircon balls with a diameter of 10mm were employed for the grinding.
As the SHS reaction proceeds fast, it is probable that the SHS reaction would be already completed before the molten steel contacts with the SHS products.