Introduction to TA3 Titanium Alloy

图片3

Pure titanium TA3 has the characteristics of high specific strength, low density (4.51KG/m3) and high melting point (1660°C). As one of the α-type titanium alloys, TA3 is an industrially pure titanium alloy. It has the characteristics of high strength, low density, excellent corrosion resistance and toughness. The tensile strength of the alloy is between 350-550MPa, has good plasticity, and is easy to process, form and weld.

Chemical composition of pure titanium TA3

material

TA3（%）

chemical composition

Fe

C

N

H

O

Other individual

Other total

Ti

≦0.4

≦0.1

≦0.05

≤ 0,015

≦0.3

≦0.1

≦0.4

margin

Mechanical Properties of Pure Titanium TA3

material

TA3

mechanical properties

alloy state

tensile strength Rm N/mm2

Specified non-proportional tensile strength RP0.2N/mm2

Elongation A5 %

Solution treatment

≥240

140-310

≥20

Physical properties of pure titanium TA3

material

TA3

physical properties

density

melting point

4.57 g/cm3

1660℃

TA3 Titanium Alloy Heat Treatment

TA3 titanium alloy belongs to the α+β phase titanium alloy, which has good plasticity and forgeability in the annealed state. Heat treatment can improve the mechanical properties and structure of TA3 titanium alloy, and improve its comprehensive performance.

The recommended annealing temperature is 670-720°C, and the annealing time is 0.5-2 hours. In this temperature range, the particle size of the alloy is moderate, and the residual stress in the structure can be eliminated during annealing, and the plasticity and toughness of the material can be improved.

When there is a large stress in the TA3 titanium alloy, stress relief annealing can be performed. The recommended annealing temperature for stress relief is 530-550°C and the annealing time is 0.5-1 hour; or 470-490°C and the annealing time is 2-4 hours. Stress relief annealing can effectively eliminate the internal stress in the material and improve its stress corrosion resistance and fatigue life.

In conclusion, the heat treatment of TA3 titanium alloy can be adjusted according to the specific needs and material properties to achieve the best mechanical properties and microstructure.

TA3 titanium alloy welding

TA3 titanium alloy welding generally uses argon shielded arc welding. Argon shielded arc welding is a commonly used welding method, especially suitable for welding highly active metals such as titanium alloys. This welding method can provide a stable argon protective environment to prevent oxidation and pollution between titanium alloy and oxygen, nitrogen, water vapor in the air during the welding process, so as to ensure the quality and performance of the welded joint.

In addition to argon shielded arc welding, plasma welding, resistance welding, gas shielded diffusion welding and other methods are also commonly used for welding TA3 titanium alloys. Plasma welding is a high-energy arc welding method that provides a higher heat source and welding speed; resistance welding achieves welding by resistive heating between materials; gas shielded diffusion welding uses shielding gas in an external gas environment to achieve welding.

To sum up, there are various welding methods for TA3 titanium alloy, but argon shielded arc welding is the most commonly used method, and other methods can also be selected for welding according to specific needs.

Processing of TA3 Titanium Alloy

For the processing of TA3 titanium alloy, the following steps are usually required:

1 Vacuum smelting: Industrial pure titanium is smelted twice in a vacuum environment, at least one of which is in a vacuum consumable electrode electric arc furnace. This ensures the purity and quality of the titanium alloy.

2 Casting: After vacuum smelting, it can be cast in a vacuum shell furnace to produce titanium alloy castings.

3 Thermal processing: Industrial pure titanium can withstand thermal processing, including forging, extrusion, rolling and stretching, etc. When heating, it is necessary to pay attention to the control of the atmosphere in the furnace, maintain a neutral or weakly oxidizing atmosphere, avoid using a reducing atmosphere, let alone use hydrogen for heating. The temperature range of thermal processing is generally 800 ~ 900 ℃.

4 Cold working: Titanium alloys can also be cold worked, such as cold rolling, cold drawing, etc. When the cold working rate reaches a certain value (such as 30% to 60%), intermediate annealing should be carried out to restore the plasticity and properties of the material.

In general, TA3 titanium alloy can be prepared by vacuum melting and vacuum shell furnace casting to produce castings, which can then be hot-worked and cold-worked to meet specific application requirements. During the processing, it is necessary to control the atmosphere in the furnace to avoid the absorption of impurities, so as to ensure the quality and performance of the titanium alloy.

Why is pure titanium TA3 so hard?

The reasons for the high hardness of pure titanium TA3 are as follows:

High crystallinity: The crystal structure of pure titanium TA3 is relatively compact, the crystal grains are fine, and it has high crystallinity, which increases its hardness.

High strength and toughness: pure titanium TA3 has good strength and toughness, which can effectively resist external impact and deformation, making its hardness higher.

Poor electrical conductivity: Pure titanium TA3 has poor electrical conductivity and is not prone to electron migration and corrosion, so it can maintain a high hardness.

High density: Pure titanium TA3 has high density, compact molecular structure, and strong atomic bonding, which makes its hardness higher.

In general, the high hardness of pure titanium TA3 is mainly due to the combined effects of its high crystallinity, high toughness, poor electrical conductivity and high compactness.

Application field of TA3 titanium alloy

TA3 titanium alloy is mainly used to manufacture parts with working temperature below 360 degrees. These parts are not strong, but require high plasticity, such as the skeleton and skin of aircraft, engine accessories, corrosion-resistant pipes, valves and pumps of ships, etc. In addition, TA3 titanium alloy can also be used in parts of seawater desalination systems, heat exchangers in chemical equipment, pump bodies, distillation towers, coolers, agitators, tees, impellers, fasteners, ion pumps, compressors Gas valves and pistons, connecting rods, leaf springs, etc. of diesel engines.

In the field of chemical titanium equipment, lightweight pressure vessels are becoming a major trend. With the implementation of the country’s top ten industrial revitalization plans, the application of titanium and titanium alloys in the field of chemical equipment will usher in rapid development. Various heat exchangers, towers, and reactors in the chemical industry have begun to use industrially pure titanium, such as titanium heat exchangers, titanium condensers, titanium synthesis towers, and titanium desulfurization towers.

What is the difference between TA3 titanium and TA2 titanium?

TA3 titanium and TA2 titanium add other components on the basis of titanium itself, representing α and β phases respectively. TA2 titanium is mainly β-phase structure, TA3 titanium is mostly α-phase structure, and the mechanical properties such as density, strength, plasticity and so on are also different:

  1. Chemische Zusammensetzung

The components in TA3 titanium mainly include titanium (Ti), aluminum (Al) and Vanadium (V). The composition of TA2 titanium mainly includes titanium, aluminum and manganese (Mn).

  1. Alloy structure

TA3 titanium has an α-phase structure, which is more stable than TA2 titanium; while TA2 titanium has a β-phase structure, which has better welding performance and cold working performance.

  1. Physical properties

The density of TA3 titanium is about 4.57g/cm³, and the density of TA2 titanium is about 4.51g/cm³. The yield strength of TA3 titanium is about 550MPa, and the elongation is about 20%; the yield strength of TA2 titanium is between 480-520MPa, and the elongation is about ≥25%.

  1. Application fields

TA3 titanium has good mechanical properties and high corrosion resistance, and is widely used in nuclear power, chemical, medical and other fields; TA2 titanium is often used in aerospace and machinery manufacturing, especially where high-strength and lightweight materials are required.

In short, although TA2 titanium and TA3 titanium are both titanium alloys, they are suitable for different fields and uses due to their differences in composition, structure and properties.