Shigeru Tanaka1)

Kazuyuki Hokamoto2)

Shigeru Itoh2)

1)Kumamoto University

2)Shock Condensed Matter Research Center Kumamoto University

Shock wave and condensed matter research centerShock wave and condensed matter research center

Explosive welding of aluminum plates

with aluminum wire mesh and WC powder

Contents

Shock penetration of diamond powder into aluminum plate

Background and Purpose

Experiment

Numerical simulation

Explosive welding of aluminum plates with aluminum wire mesh and WC powder

Conclusion

Experiment

Numerical simulation

Conclusion

Future works

Background and Purpose

Background

Many automobile component parts are made from aluminum alloy.

Purpose of this study

Investigation of adding hard materials to increase the properties of aluminum using two proposed methods – experimental and numerical study

Heat release and wear resistant materials are required for some automobile components.

water

Steel

PMMA

Explosive Electric Detonator

DSample

water

Steel

PMMA

Explosive Electric Detonator

DSample

Base plate

Flyer plate

Diamond powder

Water proof seal 0.5mm thickness

Shock penetration of diamond powder into aluminum plate

(detonation velocity:7km/s, density: 1310kg/m3)Explosive: SEP 5mm thickness

Aluminum flyer and base plate (JIS: A-1050, 50x50x1.5mm)Diamond powder (10-20μm)

Experimental method

Flyer plate surface

Base plate

Air Diamond powder0.5mm

Shock wave

Flyer plateFlyer plate surface

Base plate

Air Diamond powder0.5mm

Shock wave

Flyer plate diamond powderPenetrated

Flyer plate surface

Base plate

Flyer plate

diamond powderPenetrated

Flyer plate surface

Base plate

Flyer plate

Flyer plate

Base plate

diamond powderPenetrated

separate

Flyer plate

Base plate

diamond powderPenetrated

separate

Shock penetration of diamond powder into aluminum plate

Production of composite material in this study

1 2

3

Cross sectional optical micrograph of the sample

50mm

1.5mm

Top view of recovered flyer plate (D=30mm)

50μm

Shock penetration of diamond powder into aluminum plate

Results

JWL parameter for explosive SEPJWL parameter for explosive SEP

JWL(Jones-Wilkins-Lee) equation of state for SEP explosive JWL(Jones-Wilkins-Lee) equation of state for SEP explosive

Explosive: SEPExplosive: SEPprovided by Asahi Kasei corp.provided by Asahi Kasei corp.detonation velocity: 6970(m/s)detonation velocity: 6970(m/s)detonation pressure: 15.9(GPa) detonation pressure: 15.9(GPa)

0.281.104.302.31365

wR2R1B(GPa)A(GPa)

VE

)VRexp(VR

1B)VRexp(VR

1AP2

21

1

*

V= r V= r 00(initial density of an (initial density of an explosive explosive )/r (density of a )/r (density of a detonation gas)detonation gas)

P*: PressureP*: Pressure 　　　　 E : specific E : specific internal energyinternal energyA,B,RA,B,R １１ ,R,R ２２ ,w : JWL Parameter,w : JWL Parameter

Shock penetration of diamond powder into aluminum plate

Pressure calculation for explosive

Detonation condition was decided by the reaction rate of explosives.(=W)A reaction rate W was calculated by the following formula:

VV00 ：： Initial specific volume Initial specific volume

VVCJCJ ：： Specific volume of C-J stateSpecific volume of C-J state

P*: Pressure calculated from JWL EOS

The Pressure P inside the grating of explosives is calculated from the following formula:

cjVV

VVW

0

01

*P)W1(P

Shock penetration of diamond powder into aluminum plate

Burn technique of explosive / CJ volume burn method

Material constants

Mie-Grümeisen equation of state for water and aluminum

e2

1)s1(

cP 00

02

200

P: pressuree : internal energyr0: initial densityr: density　　　　　 /1

0

Shock penetration of diamond powder into aluminum plate

Pressure calculation for water and aluminum

ρ(kg/m3) C0 (m/s) S Τ0water 1000 1490 1.79 1.65

aluminum 2710 1340 1.34 2

0 0

Flyer plate

Water

Explosive PMMA

Shock penetration of diamond powder into aluminum plate

Investigation of flyer velocity

30mm

0

100

200

300

400

500

600

700

0 0.5 1 1.5 2

Distance (mm)

Vel

ocit

y (m

/s)

Shock penetration of diamond powder into aluminum plate

Relation between acceleration distance and flyer velocity

Shock penetration of diamond powder into aluminum plate

Simplified simulation of shock powder penetration

Shock penetration of diamond powder into aluminum plate

Conclusion

It was realized that it is possible to make a aluminum based composite material by this method.

From the numerical simulation, we could see that the particles are pushed by the particle which exists in a lower position.

Problem

This method is inapplicable to hard materials like stainless steel.

Only few particles penetrated, while others remain between the plates.

Base plate

Flyer plate

Flyer plate

Wire mesh

Cover plate

WC powder Wire mesh

0.17mm

Cover plate Flyer plate Wire mesh Base plate PowderMaterial JIS:SUS304 JIS:A-1050 JIS:A-1050 JIS:A-1050 WC

Size 80x60x0.1mm 80x60x0.1mm 100 mesh 80x60x10mm 75-100μm

Explosive welding of aluminum plates with aluminum wire mesh and WC powder

Sample constitution

Explosive

Electric detonator

Sample

Anvil

PMMA

Water

D Explosive

Electric detonator

Sample

Anvil

PMMA

Water

D

1 10 2 2.7 0.5×22 20 2 1.85 0.5×23 30 2 1.4 0.5×24 30 1 0.95 0.5

Powder weight (g)No. D (mm) StratumCalculated

load pressure (GPa)

Experimental conditions

Explosive welding of aluminum plates with aluminum wire mesh and WC powder

Experimental method and conditions

No.1 (D=10mm) No.2 (D=20mm)

Explosive welding of aluminum plates with aluminum wire mesh and WC powder

100μm 100μm

Optical micrograph of recovered samples (When the distance, D is varied)

No.3 (two layer,D=30mm) No.4 (single layer ,D=30mm)

Explosive welding of aluminum plates with aluminum wire mesh and WC powder

100μm 100μm

Optical micrograph of recovered samples

(When the layer is varied)

No.1 (D=10mm)

Explosive welding of aluminum plates with aluminum wire mesh and WC powder

20μm

Magnified optical micrograph showing the crushed WC particles and aluminum

Explosive welding of aluminum plates with aluminum wire mesh and WC powder

SEM image of fracture surface

Water

Explosive PMMA

Explosive welding of aluminum plates with aluminum wire mesh and WC powder

10mm

10mm

10mm

10mm

Measurement points

Investigation of pressure history

0

0.5

1

1.5

2

2.5

3

0 10 20 30 40 50

Time (μs)

Pre

ssur

e (G

Pa) 10mm

20mm

30mm

40mm

Explosive welding of aluminum plates with aluminum wire mesh and WC powder

Numerically obtained results - pressure vs time

Explosive welding of aluminum plates with aluminum wire mesh and WC powder

10mm

SUS plate (0.1mmthickness) + aluminum plate (0.1mm thickness)

Investigation of flyer velocity at 10mm

0

200

400

600

800

1000

1200

1400

0 0.2 0.4 0.6 0.8 1

Distance (mm)

Vel

ocit

y (m

/s)

Explosive welding of aluminum plates with aluminum wire mesh and WC powder

Relation between acceleration distance and flyer velocity

Flyer plate

Base plate

Mesh wire

WC particle

Explosive welding of aluminum plates with aluminum wire mesh and WC powder

Simplified simulation and cross sectional view after etching

Conclusion

Particles were crushed by collision of particles. Some traces of particle pull out was observed.

Explosive welding of aluminum plates with aluminum wire mesh and WC powder

There is a possibility of explosive welding between plates and mesh.

Good samples were recovered using this technique.

Future works

For the purpose of improvement of thermal conductivity of aluminum, Large sized diamond particles and aluminum wire mesh will be applied for making a Al-based composite material.

Thank you for your kind attention