Titanium Grades and Relative Properties

Rolled Alloys, a supplier of titanium and titanium alloy materials, offers the information below in order to facilitate a basic understanding of the different grades of titanium and titanium alloys, and the relative properties of these grades.

 

Titanium is available in commercially pure grades and titanium alloy grades.  Alloys can be alpha titanium, beta titanium, or alpha-beta titanium.  Alpha and beta are the two different phases of titanium.  

 

The commercially pure grades are grades 1 through 4.  The differences are the limits of various elements allowed and the strength levels (minimum required strengths and elongations are shown). 

 

GRADE

Carbon

Nitrogen

Oxygen

Hydrogen

Iron

Titanium

Tensile

Yield

Elong. ( 2")

 

Max %

Max %

Max %

Max %

Max %

 

KSI

KSI

%

1

0.08

0.03

0.18

0.015

0.2

Balance

35

25

24

2

0.08

0.03

0.25

0.015

0.3

Balance

50

40

20

3

0.08

0.05

0.35

0.015

0.5

Balance

65

55

18

4

0.08

0.05

0.4

0.015

 

Balance

80

70

15

 

There are 3 alloys that are near commercially pure titanium.  They are grades 7,  11 and 12.  Grade 7 is similar to grade 2 in mechanical properties but it has an addition of up to 0.2% Pd (Palladium), which makes it the most corrosion resistant titanium alloy.  It even offers resistance to reducing acids.  Grade 11 is similar to Grade 1, except again there is an addition of up to 0.25% Pd, which enhances crevice corrosion resistance and resistance to reducing acids. Grade 12 has a slightly higher minimum mechanical property requirement than that of Grade 3 yet slightly lower than that of Grade 4. What separates Grade 12 from all of the CP grades is that it contains .6-.9% nickel content and .2-.4% molybdenum.  The table below shows the chemistry and properties of these almost CP alloys.  The properties are based on ATSM specifications of plate and strip.  Actual requirements can vary with the specification used, product form, and size range.  Unless otherwise noted, all values are maximums.

 

GRADE

C

N

O

H

Fe

Pd

Ti

Ni

Mo

TENSILE

YIELD

EL

7

0.08

0.03

0.25

0.02

0.3

0.12-0.25

Balance

 

 

58

40-65

20

11

0.08

0.03

0.18

0.02

0.2

0.2

Balance

 

 

35

20

24

12

0.08

0.03

0.25

0.02

0.3

 

Balance

0.6-0.9

0.2-0.4

70

50

18

 

The next alloy, also the most widely used, is Ti-6Al-4V or 6-4 for short.  This alloy accounts for more than half the world’s usage of titanium and is the most common of all titanium alloys.  6-4 is also frequently referred to as Grade 5. 6-4 ELI (Extra Low Interstitial) is another common grade of titanium alloy.  It is primarily used in the medical implant industry and is commonly referred to as Grade 23.  All 6-4 alloys are considered alpha beta alloys.  The 6-4 alloys are heat treatable, and a wide range of properties are attainable depending on the heat treatment.  However, 6-4 ELI is generally difficult to heat treat and to attain minimum mechanical heat treat properties due to its low maximum oxygen requirement.

 

A fairly comprehensive list of titanium alloys can be found by accessing the link:

https://en.wikipedia.org/wiki/Titanium_alloy

 

The chemistry and typical mechanical properties of bar are shown in the table below.  Minimum requirements will vary based on product form, specification, and size range.  Unless otherwise noted with a range, values are minimum requirements.  STA is short for solution treated and aged.

 

GRADE

Al

V

C

N

O

H

Fe

Y

Others

Others

 

Tensile

Yield

Elong (2")

 

 

 

 

 

 

 

 

 

Each

Total

Ti

KSI

KSI

%

5

5.5-6.75

3.5-4.5

0.08

0.05

0.2

0.0125

0.3

0.005

0.1

0.4

Balance

138-155

128-147

15-20

5 STA

5.5-6.75

3.5-4.5

0.08

0.05

0.2

0.0125

0.3

0.005

0.1

0.4

Balance

150-172

137-156

15-17

23

5.5-6.5

3.5-4.5

0.08

0.03

0.13

0.0125

0.25

0.005

0.1

0.4

Balance

128-145

118-137

> 15

 

Rolled Alloys maintains stocks of all forms of Grade 5 materials, round bar in Grade 5 STA, and round bar and welded products in Grade 23. 

 

Call us at 800-521-0332 or email help-tech@rolledalloys.com for more specific titanium questions.