Grade 6Al 2Sn 4Zr 6Mo Titanium Alloy (UNS R56260)

Jul 8 2013

Topics Covered

Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations
Fabrication and Heat Treatment
     Machinability
     Forming
     Welding
     Heat Treatment
     Annealing
     Forging
     Hot Working
     Cold Working
     Aging
Applications

Introduction

Titanium mixed with other chemical elements such as aluminum, molybdenum and zirconium produces a wide range of titanium alloys.

Grade 6Al 2Sn 4Zr 6Mo titanium alloy possesses high strength at elevated temperatures, good hardenability and good weldability. It is heat-treatable alpha-beta alloy.

The following sections will discuss grade 6Al 2Sn 4Zr 6Mo titanium alloy in detail.

Chemical Composition

The chemical composition of grade 6Al 2Sn 4Zr 6Mo titanium alloy is outlined in the following table.

Element	Content (%)
Molybdenum, Mo	6
Aluminum, Al	6
Zirconium, Zr	4
Tin, Sn	2
Titanium, Ti	Balance

Physical Properties

The physical properties of grade 6Al 2Sn 4Zr 6Mo titanium alloy are tabulated below.

Properties	Metric	Imperial
Density	4.65 g/cm³	0.168 lb/in³
Melting point	1595-1675°C	2903-3047°F

Mechanical Properties

The following table shows mechanical properties of grade 6Al 2Sn 4Zr 6Mo titanium alloy.

Properties	Metric	Imperial
Tensile strength	1210 MPa	175000 psi
Yield strength	1120 MPa	162000 psi
Poisson’s ratio	0.33	0.33
Elastic modulus	114 GPa	16500 ksi
Shear modulus	42.9 GPa	6220 ksi
Elongation at break	13 %	13 %
Hardness, Brinell	360	360
Hardness, Knoop	392	392
Hardness, Rockwell C	39	39
Hardness, Vickers	376	376

Thermal Properties

The thermal properties of grade 6Al 2Sn 4Zr 6Mo titanium alloy are tabulated below.

Properties	Metric	Imperial
Thermal expansion co-efficient (@0.000-100°C/32-212°F)	8.60 µm/m°C	4.78 µin/in°F
Thermal conductivity	7.70 W/mK	53.4 BTU in/hr.ft².°F

Other Designations

Equivalent materials to grade 6Al 2Sn 4Zr 6Mo titanium alloy are as follows:

AMS 4981
DIN 3.7164
MIL T-9046
PWA 1222
PWA 1223
PWA 1224
PWA 1225

Fabrication and Heat Treatment

Machinability

Grade 6Al 2Sn 4Zr 6Mo titanium alloy can be machined using slow speeds, right quantity of coolant flow and high feed rates. High-speed tools should be used for tooling this alloy and the recommended tool types are tungsten carbide designations C1-C4 or cobalt based.

Forming

Grade 6Al 2Sn 4Zr 6Mo titanium alloy can be hot or cold formed.

Welding

Weldabilty of grade 6Al 2Sn 4Zr 6Mo titanium alloy is rated as limited.

Heat Treatment

The material can be solution treated at 843-913°C (1550-1675°F), and then air, oil or water quenched.

Annealing

For annealing grade 6Al 2Sn 4Zr 6Mo titanium alloy, the following process is used. Triplex-Beta minus 14°C (25°F), 1-2 h, air cool; 801-857°C (1490-1595°F), 1-4 h, air cool; 593°C (1100°F), 4-8 h, and air cool. To perform stress relief, heat the material to 482-649°C (900-1200°F), hold for 1-4 h and air cool.

Forging

In case of bar and billet, forge at 843-927°C (1565-1725°F)

Hot Working

Hot working enhances the overall ductility of the material.

Cold Working

Cold working features of this material is same as that of austenitic stainless steel. Post-work annealing is recommended to re-attain favorable performance properties.