Titanium Alloys - Ti11Sn5Zr2.5Al1Mo0.2Si Physical and Mechanical Properties and Fabrication

Chemical Formula

Ti11Sn5Zr2.5Al1Mo0.2Si

Background

Ti11Sn5Zr2.5Al1Mo0.2Si, also known as Timetal 679 is a three-phase titanium alloy having an alpha + beta + compound structure at about 950°C (1742°F). To develop optimum mechanical properties, hot working should be restricted to the alpha + beta + compound phase.

Composition

Table 1. The composition of Ti4Al4Mo4Sn0.5Si0.1C.

Content

Sn

10.5-11.5%

Zr

4.0-6.0%

Al

2.0-2.5%

Mo

0.8-1.2%

Si

0.10-0.50%

Fe

<0.20%

H2

<0.0125%

Ti

Balance

Designations

Other designations for Ti11Sn5Zr2.5Al1Mo0.2Si include:

        BS TA18 Bar – 50mm ruling section

        BS TA19 Forging Stock – 50mm ruling section

        BS TA20 Forgings - 50mm ruling section

        BS TA25 Bar - 75mm ruling section

        BS TA26 Forging Stock - 75mm ruling section

        BS TA27 Forgings - 75mm ruling section

Key Properties

Physical Properties

Table 2. Typical physical properties for Ti11Sn5Zr2.5Al1Mo0.2Si.

Property

Typical Value

Density g/cm3 (lb/ cu in)

4.84 (0.174)

Mean Co-Eff of Thermal Expansion 20-100°C/°C 68-212°F/°F

8.2x10-6 (4.6)

Mean Co-Eff of Thermal Expansion 20-300°C/°C 68-572°F/°F

9.3x10-6 (5.2)

Mean Co-Eff of Thermal Expansion 20-500°C/°C 68-932°F/°F

9.6x10-6 (5.3)

Beta Transus °C±15°C (°F)

945 (1730)

Mechanical Properties

Table 3. Typical mechanical properties for Ti11Sn5Zr2.5Al1Mo0.2Si.

Property

Typical

0.2% Proof Stress MPa (ksi)

970 (141)

Tensile Strength MPa (ksi) sheet

1110 (161)

Elongation on 1 inch %

8.0

Reduction in Area %

25

Elastic Modulus GPa (Msi)

115 (17)

Fabrication

Solution Treating - 900°C (1650°F) 1hr per 25mm section, AC/OQ

Ageing - 500°C (930°F) 24hr, AC

Source: The Titanium Information Group

For more information on this source please visit The Titanium Information Group

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