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Sometimes not knowing which one to pick between Titanium Grade 2 and Grade 5 confuses professionals. This confusion not only wastes your resources but also increases programme timeline. In this article, we will cover their differences, advantages and disadvantages so you can determine the right titanium grade for your needs.
What is Titanium Grade 2?
Titanium Grade 2 is commercially pure titanium (CP) with minimum of 99% titanium. It’s well known for its reasonable strength, good ductility and outstanding corrosion resistance. This grade is used in many industries like medical, chemical processing and aerospace because of its simple fabricability and good mechanical properties.
What is Titanium Grade 5?
Titanium Grade 5 also known as Ti-6Al-4V, is an alpha-beta titanium alloy which constitutes of titanium, vanadium and aluminum. This alloy is one of the most broadly used titanium grades because of its corrosion resistance, great strength and capability to tolerate high temperatures.
Titanium Grade 2 vs. Grade 5 – Top 5 Differences
Let’s look at the main differences between titanium grade 2 and 5 through 5 important engineering parameters.
1. Chemical Properties
Chemical Composition
| Element | Titanium Grade 2 (% weight) | Titanium Grade 5 (% weight) |
|---|---|---|
| Titanium | 99 | 90 |
| Aluminum | – | 6 |
| Vanadium | – | 4 |
| Oxygen | 0.25 | 0.2 |
| Iron | 0.3 | 0.3 |
| Carbon | 0.3 | 0.08 |
Corrosion Resistance
Titanium Grade 2 has better corrosion resistance than Titanium Grade 5. It forms a stable oxide layer that protects against neutral, oxidizing and mildly reducing conditions. Grade 5 also shows good corrosion resistance but is more prone to galvanic corrosion in particular conditions like high chloride concentrations or acidic environments.
2. Mechanical Properties
- Yield Strength: Grade 5 has much greater yield strength of 880-1100 MPa than titanium’s Grade 2 which has a yield strength of 275 MPa. So Grade 5 is better for operations that need better load bearing capacity and structural soundness.
- Elongation: Titanium Grade 2 has elongation of 20-30% which is much better than titanium’s Grade 5 elongation range of 10-15%. So Grade 2 is more ductile.
- Hardness: Titanium Grade 5 is harder than Grade 2. Grade 5 has a hardness value of 379 Brinell and for Grade 2 is 250 Brinell.
- Tensile Strength: Titanium Grade 2 has tensile strength of 352 MPa. So it is suitable for moderate strength applications. Grade 5, on the other side, has higher tensile strength of 1000-1190 MPa than grade 2 which is what is needed for high performance applications.
3. Thermal Properties
Thermal Conductivity
Titanium Grade 2, has a thermal conductivity of approximately 22 W/m·K, whereas Grade 5 has lower thermal conductivity, approximately 6.8 W/m.K
Coefficient of Thermal
Titanium Grade 2 has a coefficient of thermal expansion of approximately 9.0 µm/m·K and Grade 5 a slightly lower value of about 8.6 µm/m·K because of its microstructure.
Specific Heat Capacity
Capacity of Titanium Grade 2 is around 540 J/kg·K and Grade 5 has a greater specific heat capacity about 560 J/kg·K because of the alloying elements (aluminum and vanadium).
Melting Point
Melting point is about 1660°C for Titanium Grade 2 and about 1610°C for Grade 5.
4. Applications – Titanium Grade 2 vs. Grade 5
Medical Implants
Because of its biocompatibility, Titanium Grade 2 is broadly used for stents, surgical instruments and dental implants. Grade 5 is used for making heart valve components and orthopedic implants like joint replacements and bone plates.
Aerospace Components
In fuel tanks, aircraft frames, engine parts and aerospace components, Titanium Grade 5 is used due to its great strength to weight ratio. But Grade 2 is most of the time used for making less critical things like fasteners, brackets and airframe components where corrosion resistance is important.
Power Generation
Titanium Grade 2 is used in production of condenser tubes, pipework and heat exchangers while Grade 5 is suitable for turbine components, pressure vessels and compressor blades.
Chemical Processing
Titanium Grade 2 is used in manufacturing for tanks, reactors, pipework and heat exchangers.
But pressure vessels, pump components and valves in chemical processing units are normally made from Titanium Grade 5 for outstanding strength.
Marine Equipment
Titanium Grade 5 is used to produce components that need greater strength like turbine blades, structural supports and underwater fasteners.
Because of better corrosion resistance in seawater, Grade 2 is mostly used in marine equipment like seawater pumps, propeller shafts and boat hulls.
5. Cost Considerations
The prices of Titanium Grade 5 are usually higher because of the difficult manufacturing methods and the alloying elements and cost from $15 to $20 per kg. However Grade 2 is more affordable and the price falls between $10 to $12 per kg.
Advantages and Disadvantages of Titanium Grade 2 vs. Grade 5
Titanium Grade 2
Pros:
- Titanium Grade 2 is greatly biocompatible for medical implants. When in touch with organ tissues, its non toxic nature guarantees minimal unpleasant reactions to body.
- Titanium Grade 2 is non magnetic in nature. So this makes it suitable for applications in medical implants and sensitive electronic devices where magnetic interference must be reduced.
- Titanium Grade 2 has better strength to weight ratio which improves its performance by decreasing total weight and also maintaining structural integrity at the same time.
- Because of its impressive durability, Titanium Grade 2 can withstand wear and tear in aggressive settings.
Cons:
- Titanium grade 2 is prone to galling when in high friction contact so surface damage or premature failure can occur.
- ower fatigue resistance of titanium Grade 2 can cause premature failure for the material in cyclic, loading condition.
Titanium Grade 5
Pros:
- For components that are subjected to cyclic or repetitive loading like automotive and aerospace parts, Titanium Grade 5 gives outstanding fatigue resistance.
- Grade 5 Titanium has better high temperature performance than Grade 2, and retains strength and integrity even under extreme conditions.
- Titanium Grade 5 is also weldable by latest welding option to make complicated parts.
- Titanium Grade 5 exhibits good impact resistance, and is reliable in parts subject to shock and vibration.
Cons:
- In presence of nitrogen or oxygen during welding, Titanium Grade 5 is sensitive to weld crack.
- Titanium grade 5 is very reactive so it must be stored and handled with great care to prevent contamination, damage or oxidation.
Titanium Grade 2 vs. Grade 5 – Which One You Should Choose?
The right option depends on your particular application needs. For formability and corrosion resistance in marine and chemical processing operations, Titanium Grade 2 would be the right choice. But for high strength applications like medical implants and aerospace where performance and longer life are more important, Titanium Grade 5 is better choice. You should also consider mechanical properties of both grades, environmental situations and cost, to make the correct decision.
To Sum Up
Both Titanium Grade 2 and Grade 5 have their own valuable qualities in different applications. Grade 2 is outstanding in weldability and corrosion resistance whereas Grade 5 gives great strength and durability. But the ultimate choice depends on the nature of task.
RICHCONN is the best option if you need any CNC machining services involving titanium grade 2 or grade 5. You can contact us anytime you want.
FAQs
Is Grade 5 more difficult to machine than Grade 2?
Yes Grade 5 is more difficult to machine because of its hardening characteristics and greater strength which is why special techniques and tools are needed.
Can both grades be used in additive manufacturing (3D printing)?
Yes both Titanium Grade 2 and Grade 5 can be used in additive manufacturing but their properties will impact the functionality of final product.
Are there any specific certifications for each grade?
Yes certifications may be needed depending on application and industry standards like ISO and ASTM for both grades.
Can Titanium Grade 5 be anodized like Grade 2?
Yes Titanium Grade 5 can be anodized which will not only improve its appearance and corrosion resistance but also preserve its mechanical characteristics.
Which grade is more ductile?
Titanium Grade 2 is more ductile than Grade 5. So it has better formability and is easier to process in different applications.
