TiNb Alloy Powder

Introduction to TiNb Alloy Powder

TiNb alloy powder is composed of titanium and niobium metals. It offers a unique combination of high strength, low density, biocompatibility, corrosion resistance, fatigue and creep resistance at high temperatures.

TiNb alloys are part of a broader class of titanium intermetallic materials that have superior physical, chemical and mechanical properties compared to pure titanium. The addition of niobium as an alloying element enhances certain properties and allows tailoring TiNb alloys for specific applications.

Some key advantages of TiNb alloy powder include:

• High strength-to-weight ratio
• Ability to withstand extreme temperatures and stresses
• Resists wear, abrasion and corrosion in harsh environments
• Biocompatible and non-toxic for medical uses
• Can be processed into complex shapes using additive manufacturing
• Provides design flexibility for engineers

TiNb alloys compete with nickel and cobalt-based superalloys in the aerospace industry. They also offer an alternative to stainless steels for biomedical implants and devices. TiNb alloys are enabling new applications and designs not possible with other materials.

This article provides a technical reference covering the composition, properties, processing, applications, specifications, costs and other practical aspects of TiNb alloy powder.

TiNb Alloy Powder Composition

TiNb alloys contain primarily titanium and niobium as the key constituent elements. The niobium content typically ranges from 10% to 50% by weight, with the balance being titanium.

The ratio of Ti to Nb can be adjusted to create different grades of TiNb alloys optimized for certain properties. Some common TiNb grades include:

• Ti-10Nb – 10% niobium, 90% titanium
• Ti-35Nb – 35% niobium, 65% titanium
• Ti-45Nb – 45% niobium, 55% titanium
• Ti-50Nb – 50% niobium, 50% titanium

Additionally, small amounts of other elements like zirconium, tantalum, molybdenum, chromium may be added to further enhance properties. Oxygen and nitrogen may also be present as impurities.

Table 1: Chemical composition of common TiNb alloy grades

Alloy Grade	Niobium Content	Titanium Content
Ti-10Nb	10%	90%
Ti-35Nb	35%	65%
Ti-45Nb	45%	55%
Ti-50Nb	50%	50%

Controlling the composition is critical to achieve the desired properties in the final TiNb alloy product. Powder metallurgy techniques allow precise mixing of the constituent metals into an alloy powder feedstock.

TiNb Alloy Powder Properties

TiNb alloys exhibit a range of useful physical, mechanical and chemical properties that make them suitable for high performance applications. Some key properties include:

Physical Properties

• Density – 4.5 to 5.5 g/cm3, lower than steel and nickel alloys
• Melting point – 1550 to 1750¡«C depending on composition
• Electrical resistivity – 0.5 to 0.6 Ã×´Î.m, higher than pure titanium
• Thermal conductivity – 6 to 22 W/m.K, lower than titanium

Mechanical Properties

• Tensile strength – 500 to 1100 MPa, increases with niobium content
• Yield strength – 300 to 900 MPa
• Elongation – 10% to 25%
• Hardness – 200 to 350 HV
• Fatigue strength – 400 to 600 MPa

Other Properties

• Corrosion resistance – Excellent due to protective oxide layer
• Wear resistance – Better than titanium due to hardness
• Biocompatibility – Non-toxic and non-allergenic

By adjusting the Ti/Nb ratio, properties like strength, ductility, hardness and elastic modulus can be optimized as per application requirements.

Table 2: Typical properties of Ti-35Nb alloy

Property	Value
Density	5.2 g/cm3
Melting point	1600¡«C
Tensile strength	650 MPa
Yield strength	550 MPa
Elongation	15%
Elastic modulus	60 GPa
Hardness	250 HV

TiNb Alloy Powder Applications

The unique properties of TiNb alloys make them suitable for demanding applications in various industries:

Aerospace

• Engine components – blades, discs, fasteners
• Airframe parts – landing gear, wings, fuselage
• Hydraulic systems – pumps, valves, actuators

Automotive

• Valve springs, engine valves
• Connecting rods, turbocharger rotors
• Motor racing components

Biomedical

• Orthopedic implants – knee, hip
• Dental implants, crowns
• Surgical instruments
• Medical devices

Chemical Industry

• Heat exchangers, reactors
• Pumps, valves, pipes
• Corrosion-resistant equipment

Other Applications

• Sporting goods – golf clubs, bike frames
• High-end watches and jewelry
• Electrical contacts and connectors
• High temperature furnace parts

The combination of strength, temperature resistance, corrosion resistance and biocompatibility allows TiNb alloys to substitute heavier materials across these industries.

Table 3: TiNb alloy applications by industry

Industry	Applications
Aerospace	Engine components, airframe parts, hydraulic systems
Automotive	Valve springs, engine valves, connecting rods
Biomedical	Implants, dental, surgical instruments, devices
Chemical	Heat exchangers, reactors, pumps, valves
Other	Sporting goods, watches, electrical contacts, furnace parts

TiNb Alloy Powder Processing

TiNb alloy powder can be produced via different processing routes:

Metal Powder Blending

• elemental titanium and niobium powders are blended together in the required composition
• blended powder mixture is mechanically alloyed to form the TiNb alloy powder

Gas Atomization

• molten TiNb alloy is atomized with an inert gas into fine droplets
• droplets solidify into spherical alloy powder particles

Plasma Rotating Electrode Process (PREP)

• TiNb electrode rod is melted using plasma arc and spun at high speeds
• centrifugal force causes droplets to break off and solidify into particles

Hydride-Dehydride (HDH) Method

• Ti and Nb metals are converted into brittle hydride powders
• hydride powders are blended, dehydrided, crushed and sieved

The particle size, morphology, flowability and microstructure of the powder can be controlled by selecting the appropriate manufacturing process. This influences the final properties after consolidation.

Table 4: TiNb alloy powder production methods

Method	Description	Particle Size	Morphology
Mechanical alloying	Blending and milling Ti and Nb powders	10 – 50 microns	Irregular, angular
Gas atomization	Inert gas atomization of molten alloy	15 – 150 microns	Spherical
Plasma rotating electrode	Centrifugal disintegration of melted electrode	50 – 150 microns	Spherical
HDH process	Hydriding, dehydriding, crushing blended powders	10 – 63 microns	Irregular, angular

Consolidation of TiNb Alloy Powder

TiNb alloy powder can be converted into full-density components using various powder metallurgy consolidation techniques:

Hot Isostatic Pressing (HIP)

• encapsulated powder is HIPped at high temperature and pressure

Vacuum Sintering

• powder is compacted and sintered in vacuum furnace

Spark Plasma Sintering

• powder is simultaneously heated and compressed by pulsed DC current

Metal Injection Molding (MIM)

• powder is mixed with binder, molded, debinded and sintered

Additive Manufacturing

• powder bed fusion (SLM, EBM) or directed energy deposition (DED)

HIP and vacuum sintering can achieve close to full density while retaining fine microstructure. Additive manufacturing offers greater geometric freedom. The consolidation process can be optimized to achieve the desired properties.

Table 5: TiNb alloy powder consolidation techniques

Method	Description	Density	Microstructure	Geometry
HIP	High pressure, high temperature	Near full density	Fine	Simple shapes
Vacuum sintering	Sintering in vacuum furnace	Near full density	Fine	Simple shapes
Spark plasma sintering	Pulsed current and pressure	Full density	Ultrafine	Simple shapes
Metal injection molding	Powder + binder molding	Near full density	Ultrafine	Complex shapes
Additive manufacturing	Powder bed fusion or directed energy deposition	Near full density	Coarse	Complex shapes

Specifications for TiNb Alloy Powder

TiNb alloy powder is available in various specifications tailored for different applications:

Compositions: Grades with 10% to 50% niobium content

Particle Size: 10 to 150 microns

Morphology: Spherical, irregular or blended

Production Method: Gas atomized, HDH, blended elemental

Purity: >99.5% titanium, >99.8% niobium

Oxygen Content: <2000 ppm

Flowability: Hall flow rate > 23 sec/50g

Apparent Density: ¡Ô 2.5 g/cc

Tap Density: ¡Ô 3.5 g/cc

Chemical composition, particle size distribution, morphology, flow rate and density are commonly specified properties. Custom alloys and powder specifications can be produced for specific applications.

Table 6: Typical specification of Ti-35Nb gas atomized powder

Parameter	Specification
Alloy composition	Ti-35Nb
Particle size	15 to 45 microns
Morphology	Spherical
Production method	Gas atomization
Purity	Ti >99.5%, Nb >99.8%
Oxygen content	<1500 ppm
Flow rate	>38 sec/50g
Apparent density	¡Ô 2.7 g/cc
Tap density	¡Ô 4.2 g/cc

Suppliers of TiNb Alloy Powder

Some leading global suppliers of titanium niobium alloy powder include:

• AP&C – titanium and niobium alloy powders
• Atlantic Equipment Engineers – spherical and angular powders
• TLS Technik – gas atomized TiNb alloys
• Metal Technology – blended elemental and prealloyed powders
• Sandvik Osprey – gas atomized spherical powders
• Carpenter Additive – customized alloy powders

TiNb alloys are also offered by suppliers of titanium and niobium metals. Both standardized alloys and custom compositions can be sourced from these powder producers.

Table 7: TiNb alloy powder suppliers

Company	Materials	Production Methods
AP&C	Ti, Nb, TiNb alloys	Gas atomization
Atlantic Equipment Engineers	Ti, Nb, TiNb alloys	Gas atomization, blending
TLS Technik	TiNb alloys	Gas atomization
Metal Technology	TiNb alloys	Blended elemental, prealloyed
Sandvik Osprey	TiNb alloys	Gas atomization
Carpenter Additive	Custom TiNb alloys	Gas atomization

Cost of TiNb Alloy Powder

TiNb alloy powder is more expensive than titanium or niobium powder alone. Cost depends on:

• Composition – higher Nb content increases cost
• Purity – cost increases for higher purity
• Particle size and distribution
• Production method – gas atomized powder costs more
• Order quantity – larger volumes have lower cost

Indicative pricing for TiNb alloy powder in small quantities:

• Ti-10Nb: $100 to $300 per kg
• Ti-35Nb: $200 to $500 per kg
• Ti-50Nb: $300 to $800 per kg

Pricing reduces significantly for bulk orders of hundreds of kilos or several tons.

Table 8: Indicative pricing of TiNb alloy powders

Alloy	Pricing ($/kg)
Ti-10Nb	$100 – $300
Ti-35Nb	$200 – $500
Ti-50Nb	$300 – $800

Handling and Storage of TiNb Alloy Powder

As a reactive metallic powder, some care is needed when handling TiNb alloy powder:

• Store in sealed containers in a dry, inert atmosphere to prevent oxidation and contamination
• Avoid contact with oxygen, moisture, oils, combustible materials
• Prevent accumulation of fine powders on surfaces or equipment
• Ground all conductive equipment used in handling
• Use spark-proof tools and minimize dust generation
• Wear gloves and respiratory protection when handling
• Use grounded ventilation systems and avoid dust clouds
• Keep away from heat, flames, sparks and other ignition sources
• Follow safety data sheet for proper PPE and precautions

If stored properly in a dry, inert atmosphere, TiNb alloy powder has a typical shelf life of 12 months. Improper storage conditions can lead to oxidation, loss of flowability, or ignition hazards.

Table 9: TiNb alloy powder handling guidelines

Parameter	Guidelines
Storage	Sealed containers, dry inert atmosphere
Atmosphere	Avoid oxygen, moisture, oils, combustibles
Equipment	Ground all conductive equipment
Tools	Use non-sparking tools
Ventilation	Grounded ventilation system
PPE	Gloves, respiratory protection
Precautions	Avoid heat, flames, sparks
Shelf life	12 months in inert atmosphere

Safety Data Sheet for TiNb Alloy Powder

Like other reactive metal powders, some important safety precautions for TiNb alloy:

• Wear PPE – gloves, eye protection, mask/respirator
• Avoid inhalation of powders – use respiratory protection
• Avoid contact with skin and eyes
• Wash thoroughly after handling powder
• Avoid ignition sources, powders may be flammable
• Use proper grounding and ventilation
• Inert storage atmosphere to prevent oxidation
• Avoid spills and dust accumulation on surfaces
• Follow instructions on SDS and warning labels

First aid:

• Inhalation: Move to fresh air. Get medical help if needed.
• Skin contact: Wash with soap and water. Get help if irritation persists.
• Eye contact: Flush eyes with water for 15 minutes. Get medical attention.
• Ingestion: Drink water. Get medical assistance if discomfort occurs.

Always refer to SDS from supplier for complete health and safety information before handling and processing TiNb alloy powder.

Table 10: Key safety measures for TiNb alloy powder

Safety Item	Precautions
PPE	Gloves, goggles, N95 mask
Inhalation	Use respiratory protection
Skin contact	Wash affected area with soap and water
Eye contact	Flush eyes with water for 15 minutes
Ingestion	Drink water. Get medical help if needed.
Ventilation	Use grounded ventilation hoods
Grounding	Ground all equipment during handling
Ignition	Avoid sparks, flames, heat sources
Storage	Inert atmosphere away from flammable materials

Quality Inspection of TiNb Alloy Powder

To ensure TiNb alloy powder meets specifications, various quality checks are performed:

• Chemical analysis?- ICP, GDMS or LECO analysis to verify composition and purity
• Particle size analysis?- laser diffraction or sieve analysis for size distribution
• Morphology?- SEM imaging to check particle shape and surface topology
• Flow rate?- Hall flow meter test for powder flowability
• Density?- apparent density and tap density measurements
• Oxygen/nitrogen?- inert gas fusion analysis for interstitial impurities
• Phase identification?- XRD analysis to determine phases present

Powder properties are tested on each batch to quality standards like ASTM B939, ASTM F3049, EN 10204 3.1. Powder can be blended between lots to achieve uniformity.

Table 11: Testing methods for TiNb alloy powder

Test	Method	Standard
Composition	ICP, GDMS, LECO	ASTM E1479, ASTM E2330
Particle size distribution	Laser diffraction, sieving	ASTM B822
Morphology	SEM imaging	ASTM B822
Flow rate	Hall flow meter	ASTM B213
Density	Scott volumeter	ASTM B212
Oxygen/Nitrogen	Inert gas fusion	ASTM E1019
Phase analysis	X-ray diffraction	ASTM E1876

Medical Applications of TiNb Alloy

Due to their biocompatibility, high strength and low modulus, TiNb alloys are widely used for medical implants and devices:

Orthopedic Implants

• Knee and hip replacements
• Bone plates, screws
• Spinal fixation devices
• Dental implants and bridges

TiNb alloys like Ti-35Nb and Ti-45Nb match the elastic modulus of human bone while providing high fatigue strength. This reduces stress shielding compared to stiffer titanium alloys.

Cardiovascular Devices

• Stents
• Pacemaker casings
• Guidewires
• Surgical instruments

The corrosion resistance, non-toxicity and non-magnetism of TiNb alloys make them suitable for devices that contact blood and tissues.

TiNb Alloy Grades for Medical Use

• Ti-10Nb to Ti-50Nb
• Ti-Nb-Zr, Ti-Nb-Ta for adjusted properties
• ISO 5832-11 and ASTM F2066 standards

Lower modulus Ti-35Nb and Ti-45Nb are commonly used. Higher Nb strengthens but increases modulus. Small Zr/Ta additions further tailor properties.

Advantages of TiNb Alloys for Biomedical Use

• Excellent biocompatibility and osseointegration
• High strength and fatigue resistance
• Low modulus close to bone
• Non-toxic, non-allergenic
• Corrosion resistant
• Non-magnetic

TiNb alloys provide the best combination of strength, biocompatibility, corrosion resistance and elastic modulus for implants.

Challenges of TiNb Alloy Medical Components

• Difficult machining and fabrication
• Costlier than Ti-6Al-4V alloy
• Requires rigorous quality control and testing
• Longer-term clinical data still evolving

Being relatively new for medical use, manufacturing and licensing of TiNb components can be more complex. But their advantages outweigh short-term challenges.

Automotive Uses of TiNb Alloy

The high strength, temperature resistance and fatigue life of TiNb alloys make them attractive for automotive parts:

Valve Springs

• Higher strength allows lower spring mass
• Reduces valve float at high RPM
• Allows higher power output

Engine Valves

• Withstands high temperature exhaust gases
• Resists wear and deformation
• Lightweight

Connecting Rods

• High strength-to-weight ratio
• Reduces reciprocating mass
• Allows higher RPM and power

Turbocharger Rotors

• Maintains strength at high temperatures
• Resists creep deformation
• Thermal shock resistance
• Low density

Motor Racing Components

• Lightweight suspension, chassis parts
• Superior fatigue life

Reduced mass and inertia combined with temperature and fatigue resistance lead to higher engine performance and efficiency.

Challenges of TiNb Alloys for Automotive

• High cost compared to steel alloys
• Processing difficulties with powder metallurgy
• Limited suppliers and manufacturing experience
• Uncertain cost-benefit ratio

The benefits may justify premium pricing for high-end vehicles and motorsports initially. Broader adoption depends on TiNb powder producers driving down costs.

Aerospace Applications of TiNb Alloys

TiNb alloys compete with nickel superalloys for aircraft engine and airframe applications needing strength at low temperatures:

Engine Components

• Turbine blades, discs, casings
• Compressor blades
• Shafts, fasteners
• Thrust reversers

Structural Parts

• Landing gear
• Wings, ribs, stringers
• Fuselage frames
• Hydraulic tubing

Benefits

• 30-50% lower density than Ni superalloys
• Saves weight
• Similar strength and creep resistance
• Withstands high stresses and temperatures

Challenges