A.4.3. Timetal 550 (IMI 550)

PRODUCT

Type

Metal Alloy

Chemical Composition

4% Al, 4% Mo, 2% Sn, 0.5% Si Rem. Ti

Manufacturer

Timet

PO Box 704, Witton

Birmingham B6 7UR

UK

Tel: +44 121 356-1155

Fax: +44 121 356-5413

Email: EuroSales@timet.com

www.timet.com

EXPERIENCE & AVAILABILITY

Development Status

Commercial Product

Cost Range

Low to Medium

Lot Reproducibility

BS TA45 to TA51, AFNOR TA4DE, Werk. No. 3.7185, CEN Ti P68

Space Experience

Good

GENERAL PROPERTIES (Physical, Mechanical, Thermal, Electrical, Optical)

Nature

Typical Value

Remarks

Specific Gravity

4.60

@ Room Temperature

Ultimate Tensile Strength

1062 to 1210 MPa

@ Room Temperature

Proof Stress (0.2%)

970 to 1109 MPa

@ Room Temperature

Elongation at Break

12%

@ Room Temperature

Thermal Expansion Coefficient

8.8 x 10-6 C -1

@ Room Temperature

Thermal Conductivity

8 W m -1 C -1

@ Room Temperature

Electrical Resistivity

1.59 x 10-6 W m

@ Room Temperature

PROPERTIES RELEVANT TO SPACE USE

Nature

Typical Value

Type of Test

Corrosion/Thermal

Oxidation resistant with retention of useful strength and creep resistance up to 500C.

Strong affinity for H2 (above 130C), N2 (above 800C) and O2 (above 700C), which cause embrittlement.

 

Stress Corrosion

High resistance (see note).

 

SPECIAL RECOMMENDATIONS

          Alloy possesses poor notch sensitivity characteristics, so considerable care should be taken to avoid the presence of stress raisers.

          Methyl alcohol should not be used in the pressure testing of tanks since failure can occur due to stress-corrosion cracking.