Titanium Alloys

Titanium alloys are alloys that contain a mixture of titanium and other chemical elements. Such alloys have very high tensile strength and toughness (even at extreme temperatures). They are light in weight, have extraordinary corrosion resistance and the ability to withstand extreme temperatures.

Resistance to Corrosion
When exposed to air, a thin layer of oxide forms on the surface of titanium. This layer is very difficult for most materials to penetrate. As such, titanium demonstrates fantastic resistance to corrosion – and will not suffer adverse changes (i.e. pitting, cracking) due to corrosive substances.
Whether it’s used indoors or outdoors, it will last for many years – making it an excellent choice for buildings and marine applications, where it will be continuously exposed to seawater and rain.

Strength
One of the biggest advantages of titanium is its strength. Not only is it one of the strongest metals on the planet (rivalling even steel!), it also has the highest strength-to-density ratio of any metallic element on the periodic table. This makes it a popular option in many professions.
What’s more, as it has a low density, titanium is also incredibly lightweight.
To put this into perspective, titanium has a specific gravity of 4.5 – which is approximately 40% lighter than an equal amount of copper and 60% lighter than an equal amount of iron. This is one of the reasons why it’s often used in the aerospace industry and to create structural frames.

Non-Toxic
Metals such as iron, steel and aluminium can all be toxic to humans.
By contrast, titanium is bio-compatible. It is completely non-toxic to both humans and animals (partially due to the fact that it’s resistant to corrosion) – and, as a result, can be safely implanted into the body without causing an adverse reaction. This is why titanium is commonly used within the medical industry (e.g. to permanently strengthen broken bones) and for dental implants.

Low Thermal Expansion
Titanium has a low coefficient of thermal expansion.
Essentially this means, compared to most other manufacturing materials, it will not expand and contract anywhere near as much under extreme temperatures. In fact, it expands approximately 50% less than steel, and therefore provides much greater structural stability.
This feature is especially useful if creating a superstructure that requires a rigid yet lightweight framework. It also makes titanium suitable for building applications where fire safety is paramount (e.g. skyscrapers).

High Melting Point
This is one of the key benefits of titanium. It demonstrates an exceptionally high melting point (around 1668°C) and, as such, is perfect for use in high-temperature applications. For example, it’s the metal of choice for foundries, turbine jet engines and even some satellites.
It’s worth noting, this advantage is enhanced due to the low thermal expansion mentioned above.

Excellent Fabrication Possibilities
Despite its strength, titanium is a relatively soft and ductile refractory metal. As such, it can be easily machined and fabricated to create a diverse range of metal parts and components. Due to its resistance to oxidisation, it can also be open-air and seam welded, without the need for any type of flux agent – and the weld zone will not require any form of additional protection.

Alpha Alloys
Alpha alloys are titanium alloys that are only purposely alloyed with oxygen. While other components such as carbon and iron can be found in small quantities, they only exist as impurities. As an interstitial alloying element, oxygen significantly boosts strength while decreasing ductility. The chemical and engineering industries are the primary users of alpha alloys.
Here, great corrosion behavior and deformability are more important than high (specific) strength. The main difference between commercially pure (cp) titanium grades is their oxygen concentration.

Near-Alpha Alloys
Near-alpha alloys of titanium are the most common high-temperature alloys. This alloy class is appropriate for high temperatures because it combines the superior creep behavior of alpha alloys with the high strength of alpha + beta alloys. However, their maximum working temperature is now limited to 500 to 550 ºC.

Beta and Near-Beta Alloys
Beta alloys are another type of titanium material. Manufacturers create all titanium alloys by adding enough beta-stabilizing elements to titanium. These materials have been available for many years but have only lately gained popularity. They are more easily cold workable than alpha-beta alloys, heat treatable to high strengths, and some have better corrosion resistance than commercially pure grades.

Alpha and Beta Alloys
These are typically medium to high strength materials with tensile strengths ranging from 620 to 1250 MPa and creep resistance ranging from 350 to 400°C. In addition to tensile properties, they also have low and high cycle fatigue and fracture toughness characteristics.
As a result, people developed thermomechanical and heat treatment procedures to ensure that the alloys provide an optimal balance of mechanical properties for various applications.

Prevention of Galling
Galling not only causes excessive wear on titanium but may also result in accelerated corrosion through fretting action. Simple lubrication, using graphite or molybdenum disulfide, is often sufficient to overcome galling. It is, therefore, possible to use titanium for moving parts or for parts in sliding contact with itself or other metals with light to moderate loads. Heavier loads, on the other hand, require hardened titanium surfaces. Commercially available case hardening techniques, such as plasma spraying, ion implantation, anodising or nitriding, or coating techniques such as hard chromium electroplating or flame spraying of tungsten carbide and other hard, wear-resistant materials, are used.
Such surface treatments possess the required qualities of good adherence plus wear and scuff resistance. However, careful consideration has to be given to the compatibility of the treated surface with the corrosive environment to which it will be exposed.

Cleaning Titanium Equipment
The efficiency of titanium surfaces can usually be maintained without elaborate cleaning procedures. There is generally no need to clean for corrosion protection as is sometimes required with stainless steel, nor does the thin oxide surface film in any way combine with cooling water to form heavy mineral deposits as sometimes occurs on copper based alloys.
Marine fouling of heat exchanger surfaces is sometimes controlled by chlorine injection. Titanium surfaces are totally unaffected by such treatments. Titanium surface condenser tubing is also kept clean in this way as well as by continuous cleaning systems utilizing rubber balls or nylon brushes, without deleterious effects.

Acid Cleaning
Acid cleaning of titanium surfaces to remove deposits is sometimes necessary. Conventional acid cleaning cycles can be used provided proper inhibitors are present. Organic inhibitors such as filming amines are not effective with titanium. Ferric ion as ferric chloride is very effective as an inhibitor for titanium in acid solutions. As little as 0.1 percent (by weight) ferric chloride will inhibit corrosion of titanium by hydrochloric acid, for instance. At ambient temperatures, as much as 25 percent (by weight) HCl inhibited with FeCl3 can be safely used on titanium.
Nitric acid is an excellent passivating agent for titanium and may be used alone or with hydrochloric acid to clean titanium surfaces.

Brush Cleaning
The use of carbon steel wire brushes to remove deposits from titanium is not recommended. Likewise, carbon steel pipe or tube should not be used to clean out plugged titanium tubes. Pickup of imbedded or smeared iron particles from steel can render titanium susceptible to corrosion when the unit is placed back in service. Stainless steel or titanium wire brushes and pipe are preferred. Careful utilization of titanium’s unique properties will provide many years of maintenance-free service for fabricated equipment. Misapplication of titanium, the use of improper cleaning procedures and other abuses can lead to failure. On the other hand, careful use of some preventive measures, particularly those concerned with corrosion and galling resistance, can significantly extend the useful life of titanium equipment.

Application Requirements
The primary factor in selecting a titanium alloy is the intended application. Whether you’re working in aerospace, medical, automotive, or any other industry, the alloy’s mechanical and chemical properties must align with your project’s demands. For instance, Ti-6Al-4V (Grade 5) is a popular choice for aerospace components due to its high strength and corrosion resistance.

Strength and Weight
Titanium is valued for its exceptional strength-to-weight ratio. Different alloys offer varying levels of strength, with some surpassing the strength of many steel alloys. Balancing strength and weight is crucial in applications like sports equipment and prosthetics.

Corrosion Resistance
Titanium’s corrosion resistance is legendary. Its alloys are used in harsh environments where corrosion is a concern, such as marine applications and chemical processing. Ti-6Al-4V and Ti-6Al-4V ELI are known for their exceptional resistance to corrosion.

Temperature Resistance
In applications involving extreme temperatures, such as jet engines or heat exchangers, you must choose an alloy that can withstand the conditions. Alloys like Ti-6Al-4V, Ti-6Al-4V ELI, and Ti-5Al-2.5Sn offer excellent high-temperature performance.

Fabrication and Machinability
Consider the ease of fabrication and machinability when selecting a titanium alloy. Some alloys can be challenging to work with, while others are more user-friendly, depending on your manufacturing process.

The Group adheres to the principle of "one-stop service, making choices easier". Continuing to meet the different needs of global customers in the field of the world's steel supply chain. A professional sales team provides customers with first-class services. A rigorous procurement and quality inspection team selects high-quality raw materials. A shipping and logistics team that ensures the protection of product transportation.