Grade 3 Unalloyed Ti ("Pure") 65A (UNS R50550)

Topics Covered

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

Introduction

Commercially pure titanium alloys can be altered via small quantities of oxygen and iron, that tend to influence the mechanical properties. Each commercial grade is suited for different applications.

Grade 3 Unalloyed Ti ("Pure") 65A alloy is a general purpose alloy that is non-magnetic, and has excellent corrosion resistance in highly oxidizing to mildly reducing environments and excellent strength to weight ratio. It is a slightly stronger version of grade 2 titanium alloy. It also has good impact properties at low temperatures.

The following sections will discuss in detail about grade 3 Unalloyed Ti ("Pure") 65A alloy.

Chemical Composition

The chemical composition of grade 3 Unalloyed Ti ("Pure") 65A alloy is outlined in the following table.

Element Content (%)
Titanium, Ti ≥ 98.8
Iron, Fe ≤ 0.30
Oxygen, O ≤ 0.35
Carbon, C ≤ 0.080
Nitrogen, N ≤ 0.050
Hydrogen, H ≤ 0.015

Physical Properties

The physical properties of grade 3 Unalloyed Ti ("Pure") 65A alloy are tabulated below.

Properties Metric Imperial
Density 4.51 g/cm3 0.163 lb/in3
Melting point 1680°C 3056°F

Mechanical Properties

The following table shows mechanical properties of grade 3 Unalloyed Ti ("Pure") 65A alloy.

Properties Metric Imperial
Tensile strength 585 MPa 84800 psi
Yield strength 345 MPa 50000 psi
Poisson's ratio 0.34-0.40 0.34-0.40
Elastic modulus 105 - 120 GPa 15200 - 17400 ksi
Elongation at break 25% 25%
Hardness (HV) 180-220 180-220

Thermal Properties

The thermal properties of grade 3 Unalloyed Ti ("Pure") 65A 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 21.97 W/mK 152.5 BTU in/hr.ft².°F

Other Designations

Equivalent materials to grade 3 Unalloyed Ti ("Pure") 65A alloy are as follows:

  • AMS 4900
  • ASTM B337
  • ASTM B338
  • ASTM B381
  • ASTM F67

Fabrication and Heat Treatment

Machinability

Grade 3 Unalloyed Ti ("Pure") 65A alloy is hard to machine but can be successfully done using slow speeds, high coolant flow, and high feed rates. Tooling should be performed using tungsten carbide designations C1-C4 or cobalt type high speed tools.

Forming

Grade 3 Unalloyed Ti ("Pure") 65A alloy can be hot or cold formed using power brake, hydropress, stretch or drop hammer methods.

Welding

Weldability of grade 3 Unalloyed Ti ("Pure") 65A alloy is rated as excellent.

Annealing

Annealing of this material can be performed by heating to 704°C (1299°F), and then held for 2 h, which should be followed by air cooling. In case intermediate stress relieving is required, the material has to be heated to 482-538°C (900-1000°F) for 45 min.

Forging

Rough forging can be performed at 907°C (1165°F) and completed at 843°C (1550 °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 a moderately tempered austenitic stainless steel. Post-work annealing is recommended to re-attain favorable performance properties.

Applications

Grade 3 Unalloyed Ti ("Pure") 65A alloy is used in the following application areas:

  • Navy ship parts
  • Chemical processing equipment
  • Power plant cooling system components

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Submit