TiAl3 Powder

TiAl3 powder is an intermetallic compound composed of titanium and aluminum. It is lightweight, oxidation resistant and can withstand high temperatures. This makes it suitable for use in aerospace, automotive, energy and other high performance applications.

Some key properties and characteristics of TiAl3 powder:

TiAl3 Powder Properties and Characteristics

Chemical formula	TiAl3
Density	3.4 g/cm3
Melting point	1395¡«C
Young’s modulus	170 GPa
Coefficient of thermal expansion	11 x 10-6 K-1
Thermal conductivity	29 W/m-K
Electrical resistivity	125 Ã×´Î-cm
Oxidation resistance	Excellent up to 1000¡«C

TiAl3 powder can be produced through various methods including gas atomization, plasma rotating electrode process (PREP), and mechanical alloying. The powder size, morphology, composition, microstructure and other properties depend on the production method.

The titanium content is typically in the range of 55-65 wt% and aluminum makes up the balance. Small amounts of chromium, niobium, carbon, or oxygen may be present up to 1% maximum. The ratio of Ti:Al can be adjusted to optimize properties.

TiAl3 Powder Properties

Property	Value
Density	3.7-4.0 g/cm3
Melting Point	1350¡«C
Thermal Conductivity	~20 W/m-K
Electrical Resistivity	125-185 Ã×´Î-cm
Young’s Modulus	160-180 GPa
Poisson’s Ratio	0.25-0.35
Coefficient of Thermal Expansion	11-13 x 10<sup>-6</sup>?/¡«C

Key properties include low density compared to titanium alloys, high melting point, moderate thermal conductivity, and retention of strength and stiffness at high temperatures.

TiAl3 Powder Characteristics

Attribute	Details
Particle Shape	Predominantly spherical
Particle Size	10 – 150 Ã×m
Flowability	Good
Apparent Density	~2.5 g/cm3
Tap Density	~3.5 g/cm3
Surface Area	0.1-0.3 m2/g
Purity	>99.5%

TiAl3 powder has spherical morphology with smooth surface, good flow and packing characteristics. It has low oxygen and nitrogen to avoid embrittlement.

Applications of TiAl3 Powder

Some of the major applications taking advantage of the properties of TiAl3 include:

TiAl3 Powder Applications in Additive Manufacturing

• TiAl3 powder is used in powder bed fusion processes like selective laser melting (SLM) and electron beam melting (EBM) to fabricate complex titanium aluminide components for aerospace and automotive.
• It has lower reactivity and easier printability compared to Ti6Al4V in powder bed AM. TiAl3 parts have fine microstructure and mechanical properties comparable to cast and wrought alloys.
• AM with TiAl3 enables lighter weight designs, reduced part count, and consolidation of assemblies for turbine blades, turbocharger wheels, exhaust components, etc.

TiAl3 Powder Applications in Thermal Spray

• Thermal spray coatings of TiAl3 powder provide oxidation and corrosion resistance at high temperatures on turbine blades, vanes, combustion cans, etc.
• It has better temperature capability than nickel alloys and titanium coatings. TiAl3 coatings can operate at 700-900¡«C.
• Coatings are applied via plasma spray, high velocity oxy-fuel (HVOF), or warm spray processes. Typical coating thickness is 150-500 microns.

TiAl3 Powder Applications in Laser Cladding

• TiAl3 powder can be laser clad on titanium or nickel alloy substrates to form a protective surface alloy layer.
• The clad layer imparts improved high temperature strength, oxidation resistance, and wear resistance.
• Laser cladding is used on jet engine and land-based turbine components exposed to hot corrosion conditions.

TiAl3 Powder Specifications

TiAl3 powder is available in several standard grades that conform to specifications such as:

TiAl3 Powder Compositions

Grade	Ti wt%	Al wt%	Other
Ti-45Al-3Nb	45%	Balance	3% Nb
Ti-55Al	55%	Balance	–
Ti-62Al	62%	Balance	–

Common compositions are based on the titanium content such as Ti-45Al, Ti-55Al or Ti-62Al representing the weight percentage of titanium. Small amounts of chromium or niobium may be present.

TiAl3 Powder Particle Size Distribution

Particle Size	Distribution
-150 +45 Ã×m	5% max
-45 +22 Ã×m	40-60%
-22 Ã×m	Balance

Typical size distributions for AM processes are centered around 22-45 Ã×m with minimum fines below 22 Ã×m. Larger sizes up to 150 Ã×m are used for thermal spray.

TiAl3 Powder Standards

• ASTM B821 – Standard for Preparation of Refractory Alloy Powders and Compacts via Plasma Techniques
• AMS 4982 – Powder Consumables, Titanium Aluminides, Plasma Atomized
• AMS 7008 – Titanium Aluminide Alloy Powder for Thermal Spray Coatings

Powder manufacture, sampling, testing, and acceptance follow industrial standards for refractory alloys and titanium aluminides.

TiAl3 powder has some advantages and disadvantages compared to other commonly used powders:

Comparison of TiAl3 Powder with Other Powders

Parameter	TiAl3	Ti6Al4V	AlSi10Mg
Density	Lower	Higher	Lower
Strength at high temperature	Higher	Lower	Much lower
Oxidation resistance	Excellent	Moderate	Poor
Thermal conductivity	Higher	Lower	Higher
Cost	Higher	Lower	Lower
Manufacturability	More difficult	Easier	Easier
Applications	Aerospace, automotive	Aerospace, biomedical	Automotive, general

• TiAl3 has higher strength than titanium alloys like Ti6Al4V at temperatures above 600¡«C
• It offers better oxidation resistance compared to titanium and aluminum alloys
• More expensive than titanium alloys due to high aluminum content
• Not as easily machined or formed as titanium alloys at room temperature
• Best suited for high temperature structural applications

By understanding where TiAl3 outperforms or underperforms compared to other alloy systems, the ideal applications can be identified to leverage its advantages.

TiAl3 Powder Suppliers

TiAl3 powder is commercially available from a number of suppliers globally. Some of the major manufacturers are:

TiAl3 Powder Manufacturers

Company	Product Grades	Location
AMETEK	TiAl3-100A, TiAl3-500	USA
AP&C	TiAl3-230, TiAl3-360	Canada
Sandvik	TiAl3 Osprey Powder	Sweden
TLS Technik	TiAl3-100A	Germany
Praxair	TiAl3-100A	USA

TiAl3 Powder Pricing

Grade	Particle Size	Price Range
TiAl3-100A	15-45 Ã×m	$450-$550/kg
TiAl3-230	45-180 Ã×m	$350-$450/kg
TiAl3-500	10-45 Ã×m	$500-$600/kg

Prices depend on purchase volume, purity levels, particle size distribution and morphology. Custom alloy compositions are also possible but more expensive.

FAQs

Q: What methods can be used to produce TiAl3 powder?

A: The main production methods are gas atomization, plasma rotating electrode process, and mechanical alloying. Each method results in different powder characteristics suited for different applications.

Q: Is TiAl3 compatible with titanium alloys?

A: TiAl3 has very limited solid solubility in titanium alloys like Ti6Al4V. It is not recommended to mix TiAl3 powder with titanium alloy powders due to formation of brittle intermetallic phases.

Q: What alloying elements can be added to TiAl3?

A: Elements like Nb, Cr, Ni, Cu have been alloyed with TiAl3 to modify the microstructure and mechanical properties. However, excessive alloying can negatively impact oxidation resistance.

Q: What is the difference between PREP and gas atomized TiAl3 powder?

A: PREP powder has fine spherical particles ideal for additive manufacturing whereas gas atomized powder has slightly coarser, more cost-effective particles suitable for pressing and sintering.

Q: What precautions should be taken when handling TiAl3 powder?

A: TiAl3 powder is flammable and prone to oxidation. Proper PPE should be worn and handling should occur under inert atmosphere to prevent contamination. Moisture and oxygen exposure degrades powder quality.

Conclusion

In summary, TiAl3 is an important high temperature intermetallic material available in powder form for various applications. Its properties like low density, strength, and oxidation resistance at elevated temperatures make it suitable for aerospace, automotive and energy industries. Proper handling, storage and testing of the powder is critical to achieving final part properties. TiAl3 offers advantages over conventional titanium alloys for high temperature structural use cases despite some limitations in machinability and room temperature ductility. Ongoing research aims to further improve the material by alloying additions and innovative processing techniques.