Acoustical Properties Of Common Materials

Material

Ultrasonic Velocity

Longitudinal

Transverse (Shear)

Impedance

in / us

mm / us

in / us

mm / us

Z

METALS

Aluminum 1100-0

0.248

6.229

0.121

3.073

17.1

Aluminum 2024-T4

0.251

6.375

0.124

3.150

17.6

Aluminum 6061-T6

0.248

6.299

0.124

3.150

17.0

Beryllium

0.507

12.878

0.350

8.890

23.5

Brass (70% Cu - 30% Zn

0.172

4.369

0.083

2.108

37.1

Bronze (Phosphor 5%)

0.139

3.531

0.088

2.235

31.3

Copper (CP)

0.187

4.750

0.092

2.337

42.5

Gold

0.128

3.251

0.047

1.194

62.6

Hastelloy C

0.230

5.842

0.114

2.896

52.2

Hastelloy X

0.228

5.791

0.108

2.743

47.7

Inconel (Wrought)

0.308

7.823

0.119

3.023

64.5

Iron (Cast), Various Alloys

0.138-0.220

3.505-5.588

0.087-0.126

2.210-3.200

24.3-41.2

Lead (94Pb-6Sb)

0.085

2.159

0.032

0.813

23.5

Magnesium, Various Alloys

0.215-0.228

5.461-5.791

0.119-0.122

3.023-3.099

9.24-10.6

Monel

0.211

5.359

0.107

2.718

47.2

Nickel (CP)

0.222

5.639

0.117

2.972

50.0

Silver (0.99 Fine)

0.142

3.607

0.063

1.600

37.8

Steel 1020

0.232

5.893

0.128

3.251

45.4

Steel 4340

0.230

5.842

0.128

3.251

45.6

Steel , CRES 300 Series

0.221-0.226

5.613-5.740

0.120-.0123

3.048-3.124

44.6-45.4

Steel , CRES 400 Series

0.212-0.237

5.385-6.020

0.118-0.132

2.997-3.353

41.3-46.3

Titanium, 6AI-4V

0.243

6.172

0.130

3.302

27.3

Zircaloy

0.186

4.724

0.093

2.362

44.2

Zirconium

0.183

4.648

0.089

2.261

30.1

POLYMERS

Acrylics

0.105-0.109

2.667-2.769

0.044-0.057

1.118-1.448

3.15-3.51

Cellulose Acetate

0.096

2.438

No Shear Component

3.19

Nylon

0.016

2.692

No Shear Component

 -------------

Phenolic

0.056

1.422

No Shear Component

1.90

Polycarbonate

0.090

2.286

No Shear Component

2.71

Polyethylene

0.105

2.667

No Shear Component

2.94

Polystyrene

0.094

2.388

0.045

1.143

2.52

Rubber (Natural)

0.061

1.549

No Shear Component

1.74

Rubber (Carbon Filter)

0.066

1.676

No Shear Component

 -------------

Rubber (Silicone)

0.037

0.94

No Shear Component

1.40

Teflon

0.054

1.372

0.250

6.35

3.00

MISCELLANEOUS SOLIDS

Alumina (Al2O3)   

0.427

10.846

No Shear Component

43.1

Concrete

0.167-0.207

4.242-5.258

0.135

3.429

12.4

Glass (Plate)

0.227

5.766

No Shear Component

14.5

Granite

0.156

3.962

0.076

1.93

10.9

Ice ( -16C)

0.150

3.81

No Shear Component

3.60

Quartz, Natural

0.226

5.74

0.139

3.531

15.2

Quartz, Fused

0.219

5.563

0.302

7.671

14.5

Sapphire

0.469

11.913

0.157

3.988

47.2

Tungsten Carbide

0.262

6.655

No Shear Component

67.6

COMPOSITE MATERIALS

Fiberglass (50 v/o)

0.124

3.15

0.068

1.727

6.04

Graphite/Epoxy (60 v/o)

0.117

2.972

0.077

1.956

4.65

Boron/Epoxy (50v/o)

0.131

3.327

0.072

1.829

6.38

LIQUIDS

Ethylene Glycol

0.064

1.626

No Shear Component

1.80

Glycerin

0.076

1.93

No Shear Component

2.42

Oil (SAE 20)

0.069

1.753

No Shear Component

1.51

Water (20C)

0.058

1.473

No Shear Component

1.48

Gases

Air (20ºC)

0.014

0.356

No Shear Component

0.00041

Nitrogen (20ºC)

0.014

0.356

No Shear Component

0.00041

Oxygen (20ºC)

0.013

0.33

No Shear Component

0.00043