BOMBARDING OF MATERIALS WITH

EXPLOSION-ACCELERATED PARTICLES:

EVALUATION OF DEVELOPED

PRESSURES

E.V. Petrov1, R.G. Kirsanov2, and A.L. Krivchenko3

1 Institute of Structural Macrokinetics and Materials Science, Russian Academy of Sciences, Chernogolovka 2 Samara State Agricultural Academy, Ust-Kinelskii 3 Samara State Technical University, Samara

Objects of research2

Cylinders h=40 mm, ø 24 mm material-(steel – U8)

TiN – powder (tmel=2947 0С, ρ=5,44 g/сm3),

particles size 45 – 57 μm (74%), used as the main material  for

practical purposes.

Histogram of particles TiN

W powder (tmel=3380 0С, ρ=19,3 g/сm3),

particles size 13 – 16 μm (55%), used as model

material

Histogram of particles W

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Scheme of experiment

1 − detonator, 2 − explosive, 3 – air clearance, 4 – steel tube, 5 – ring, 6 – powder particles, 7 – sample (steel U8).

Investigations of the microhardness distribution at the depth of 4 mm, steel U8

sample height is 40 mm

The increase of the samples hardness :900 – by powder particles by 26 %900 – by shock wave by 16 %600 – by powder particles by 38 %600 – by shock wave by 28 %450 – by powder particles by 32 %450 – by shock wave by 22 %

Collision angle - 900

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Collision angle - 600

Collision angle - 450

Cross-section of the sample

X-ray spectral microanalysis (LEO-1450)The sample treated by TiN powder

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TiN particles into the sample, depth ~ 2 мм, collision

angle – 600

Spectrum C Ti N Fe

1 23.45 5.36 23.19 48.00

2 24.63 11.01 25.84 38.52

Microanalysis of TiN particles (atomic%)

Near-surface layer of obstacle,

collision angle – 900

Penetration depth of TiN particles is about 2,1 – 2,3 mm that much more than initial particles size (60 μm), in 38 times

Element App. Conc.

Weight

%

Atomic %

C 3,99 8,54 45,77

Fe 27,19 25,92 29,90

W1 52,55 65,82 20,57

WS1 58,04 69,47 24,33

The sample treated by W powder, collision angle is 900

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W particles into the sample:3 mm 0,126 mm

Microanalysis W particles

Near-surfacelayer of obstacle

Penetration depth of W particles is about 126 μm that much more than initial particles size (14 μm ), in 9 times

X-ray spectral microanalysis (LEO-1450)

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1. Experimental evaluation of pressure, with using  electret  polivinildihlorid transducer gave us values of  1-2 GPa (Aleksentseva S.E., Kalashnikov V.V., Krivchenko A.L., Tsivinskaya L.V., Interaction of Accelerated Particles with Metals, Abstr. Symp. on Synergism, Materials Structure, and Self-Assembling Technologies, Moscow, 1996, pp. 24–25. )

2. To value the interaction parameters between particle flow( we study it as porous body) and steel sample we use the methodology agreed impedances. It’s shown:

• when the porosity (m) = 3,9 the incoming shock wave pressure (P) in steel = 34 GPa

• when the porosity (m) = 4,5 then P = 25 Gpa• when the porosity (m) = 8 (the porosity of W particle flow in

the experiment, ) then P = 10-13 GPa. (Kirsanov R.G. The study of the kinetics of the processes, changes in the structure and properties of metals under shock-wave action flux of discrete particles in the mode of super-deephpenetration: dissertation Candidate of Physical Mathematical Sciences: 01.04.07. / Samara, 1997. – 139 p.

Estimated value of pressure in the collision flow of particles W and TiN with a steel sample

Estimated value of pressure in the collision flow of particles W and TiN with a steel sample

Conservation equation of impulse

DUP 0

bUaD

where ρ0 – density; D – speed of the shock jump; U – the mass velocity.

WbWaP FeFe WUWUbaP TiNWTiNW ,,

where a and b – coefficients;For steel: а= 3800 m/s, b= 1,58For W: а= 4010 m/s, b= 1,24For TiN: а= 6280 m/s, b= 1,154

Numerical estimate:for W: Р = 62 GPa; for TiN: Р = 41 GPa.

Linear equation of the shock adiabat

UbUaP 0

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It is shown that interaction of the explosion-accelerated particle flow with the obstacle is accompanied by three types of interaction:1.The relatively weak interaction of detonation products flow with the material of obstacles. Pressure in obstacle does not exceed the pressure of the elastic precursor - 1 GPa.2.More stronger interaction of the particle flow  with the material of obstacles. Pressure on whole of sample surface - 10-13 Gpa (calculated by the reflection of shock adiabats).3.Locally strong interaction of the one particle with obstacle surface. In this case, pressure for W particles = 62 Gpa, TiN particles  = 41 GPa (calculated from the equations of the shock adiabats).

Сonclusions:9

Thank you for attention

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