Transcript Document

Department of Explosion
Laboratory of High-Speed Processes
Laboratory of Dynamic Loading
Laboratory of High-Speed Processes
Super-hard materials: Cubic silicon nitride
Shock synthesis: β-Si3N4 → c-Si3N4
►
Static HPHT burning: 1100°C, 5-6 GPa,
1-5 hours ► nano-bulks
nano-dispersive powder
HV, GPa
Micro-hardness vs load to indenter ►
P i, g
Scale – 1 mm
1-3 – our, 4-5 – Japan, 6-7 – USA
2-fold harder than others
Investigation of detonation and shock
waves by synchrotron radiation
 1-D and 2-D density distribution behind shock and
detonation front
 SAXS for kinetics of crystal phase and cracks
growing during explosion events
 Dynamic X-ray diffraction
Technical data:
• SR beam 15x0.1 mm in size, exposure – 1 ns, repeat – 250 ns
• Energy of γ-quantum up to 20 kV
• X-ray quantometer up to 256 channels
• single detector 0.1 mm in width
• explosive chamber up to 50 g of HE investigated
Hardware for experiments
Laboratory of Dynamic Loading
Staff:
3 professors, 2 senior researchers (Ph.D), 1 research officer
Principal research topics: Investigation of pulse loading and deformation processes
of homogeneous and heterogeneous media for developing of advanced materials.
Equipment: explosive chambers, digital oscilloscopes, pulse generators, scanning
electron microscope, optical microscopes.
Explosive chambers: a) KV-2, max weight of
explosive charge is 1 kg, b) VK-15 max weight of
explosive charge is 5 kg. b
a
Scanning electron
microscope LEO-420 with
X-ray microanalyser
RONTEC
Explosive welding: a) fragments of heat
exchanger and crystallizer, b) multi-layer
composite materials.
a
b
Explosive compaction: metal-ceramic composite
materials and products.
Developing microcrystalline materials
by dynamic methods
Microstructure of compact
from internally oxidized
copper alloy Cu - 0,4%Al
30
25
20
15
10
Grain size - d mcm
0.
8
0.
85
0.
7
0.
75
0.
6
0.
65
0.
5
0.
55
5
0
0.
1
0.
15
0.
2
0.
25
0.
3
0.
35
0.
4
0.
45
Fragmentation in form of block
structures is visible after shockwave loading of fine-grained
materials
Quantity of
grains -N
Grain size distribution after intensive plastic
deformation in composite Cu-Al2 O3
Measurement of a cumulative jet temperature
5
4
1
a
2
R
b
3
The experimental set-up (a)
and a photo of measuring
element (b) for measurement
of temperature of a metal jet.
1 – the copper cylinder with
semispherical hollow, 2 - the
insertion from constantan, 3 a rod from constantan, 4 - a
compound
charge
of
explosive, 5 - a detonator.
The X-ray photograph of
impact of a cumulative jet
and a rod.
Measurement of mass velocity behind
shock wave front in powder
6
5
3
2
1
4
The set-up (a) and a
photo (b) of experimental
assembly: 1 - a researched
powder, 2 - an aluminium
foil, 3 - a coil - source of
a magnetic field, 4 - the
measuring coil, 5 - a compound charge of explosive, 6 - a detonator.
D , км/с
3.0
2.5
2.0
u , км/с
1.5
0
0.5
1.0
1.5
2.0
( D - u) - the diagram of shock
compression Al2O3 powder with
initial density 1.06 g/sm3.