CoCrMoW Powder

Overview of CoCrMoW Powder

CoCrMoW powder is a cobalt-chromium-molybdenum-tungsten alloy powder used primarily for manufacturing of orthopedic joint implants. The addition of tungsten further enhances the strength, wear resistance and hardness compared to CoCrMo alloys.

Key properties and advantages of CoCrMoW powder include:

CoCrMoW Powder Properties and Characteristics

Properties	Details
Composition	Co-Cr-Mo-W alloy
Density	9.2 g/cc
Particle shape	Spherical
Size range	15-45 microns
Apparent density	Up to 60% of true density
Flowability	Good
Corrosion resistance	Excellent due to Cr oxide layer
Biocompatibility	High, suitable for implants
Wear resistance	Extremely good from W and Cr
Strength	Very high from solid solution strengthening

With its unique combination of biocompatibility, high hardness, strength and toughness, CoCrMoW enables manufacturing of high performance orthopedic implants using 3D printing or metal injection molding.

CoCrMoW Powder Composition

CoCrMoW Powder Composition

Element	Weight %
Cobalt	Balance
Chromium	26-30%
Molybdenum	5-7%
Tungsten	4-6%
Carbon	< 0.35%
Manganese	< 1%
Silicon	< 1%
Iron	< 1%
Nickel	< 1%

• Cobalt provides strength, biocompatibility, aids solid solution strengthening
• Chromium for oxidation resistance and corrosion resistance
• Molybdenum contributes to solid solution strengthening
• Tungsten significantly improves wear resistance and hardness
• Other elements present as impurities

The high Cr, Mo and W content result in an excellent combination of strength, hardness and corrosion resistance required for orthopedic implants.

CoCrMoW Powder Physical Properties

CoCrMoW Powder Physical Properties

Properties	Values
Density	9.2 g/cc
Melting point	1370-1430°C
Electrical resistivity	96 μΩ-cm
Thermal conductivity	16 W/mK
CTE	14.5 x 10^-6 K^-1
Curie temperature	1160°C

• High density compared to CoCrMo and titanium alloys
• Maintains strength and hardness at elevated temperatures
• Relatively low thermal conductivity
• Becomes paramagnetic above Curie temperature
• CTE higher than competing alloys in implant applications

The properties allow use in load bearing orthopedic implants requiring high temperature strength, hardness and corrosion resistance.

CoCrMoW Powder Mechanical Properties

CoCrMoW Powder Mechanical Properties

Properties	Values
Hardness	43-52 HRC
Tensile strength	1310-1650 MPa
Yield strength	1035-1450 MPa
Elongation	8-15%
Modulus of elasticity	240-310 GPa
Compressive strength	1700-2100 MPa

• Excellent combination of very high strength and hardness
• Strength levels exceed requirements for load bearing implants
• Reasonable ductility for a hard material
• High modulus provides stiffness required for implants
• High fatigue strength ensures durability

The mechanical properties make CoCrMoW powder highly suitable for manufacturing strong, wear resistant orthopedic implants using AM techniques.

CoCrMoW Powder Applications

Primary applications of CoCrMoW powder include:

CoCrMoW Powder Applications

Application	Examples
Orthopedic implants	Knee, hip, dental implants
Medical devices	Surgical tools and instruments
Aerospace	Aircraft engine components
Automotive	Fuel injection parts, valves
Industrial	Cutting tools, dies, molds

Some specific product uses of CoCrMoW alloy powder:

• Articulating surfaces in joint replacement implants
• Dental crowns, bridges and root caps
• Maxillofacial implants, skull plates
• Aircraft engine turbine blades and housings
• Automotive engine valves and fuel injection nozzles
• Cutting tools and industrial tooling

The combination of outstanding mechanical properties, corrosion resistance and biocompatibility provides maximum performance for these demanding applications.

CoCrMoW Powder Specifications

Key standards for CoCrMoW powder:

CoCrMoW Powder Standards

Standard	Description
ASTM F75	Standard for wrought CoCrMo alloy for surgical implants
ASTM F1537	Wrought CoCrMoNi alloy for dental applications
ASTM F3001	Specification for additive manufacturing of medical implants using powder bed fusion
ISO 5832-4	Wrought CoCrMoNi alloy for surgical implants

These standards specify:

• Limits on composition, impurities
• Minimum mechanical property requirements
• Production method – inert gas atomization
• Acceptable particle size distribution
• Testing protocols for quality assurance
• Powder characterization requirements

Compliance with standards ensures suitability for critical orthopedic implant applications.

CoCrMoW Powder Particle Size

CoCrMoW Powder Particle Size Distribution

Particle size	Characteristics
15-25 microns	Used in laser powder bed fusion (LPBF)
25-45 microns	Used in binder jetting and DMLS
10-45 microns	Used in metal injection molding

• Finer powder provides higher resolution and surface finish for AM
• Coarser powder has better flowability for powder processing
• Balanced size distribution optimized for each production method
• Tight control over particle size distribution is maintained

Controlling particle size and morphology allows high packing density and optimized sintering.

CoCrMoW Powder Apparent Density

CoCrMoW Powder Apparent Density

Apparent density	Characteristics
Up to 60% of true density	For spherical powder morphology
4.5-5.5 g/cc range	Due to voids between particles

• Higher apparent density improves powder flow and compressibility
• Spherical powder shape allows greater packing density
• Values up to 65% are possible with optimized powder

Higher apparent density results in better manufacturing productivity and part quality.

CoCrMoW Powder Production Method

CoCrMoW Powder Production

Method	Details
Gas atomization	High pressure inert gas breaks up molten alloy stream into fine droplets
Vacuum induction melting	High purity starting materials melted under vacuum
Multiple remelting	Improves chemical homogeneity
Sieving	Classifies powder into different particle size fractions
Blending	Powder fractions blended to customize particle distribution

• Gas atomization produces fine spherical powder morphology
• Vacuum melting minimizes impurities like oxygen and nitrogen
• Multiple remelting improves uniformity of composition
• Post-processing allows precise control of particle size distribution

Fully automated production and strict process control ensures reliable properties and batch-to-batch consistency of the powder.

CoCrMoW Powder Pricing

CoCrMoW Powder Pricing

Factor	Impact
Powder grade	Price increases with higher purity
Particle size	Ultrafine grades more expensive
Order quantity	Price reduces for bulk orders
Powder properties	Higher apparent density costs more
Packaging	Argon filled containers raise price
Testing requirements	More rigorous testing increases cost
Lead time	Faster delivery times increase cost

Indicative Pricing

• CoCrMoW for medical applications: $120-180 per kg
• CoCrMoW for industrial applications: $80-120 per kg

Significantly lower prices are applicable for bulk orders exceeding several hundred kilograms.

CoCrMoW Powder Suppliers

CoCrMoW Powder Suppliers

Company	Location
Carpenter Additive	USA
Sandvik Osprey	UK
Hoganas	Sweden
Praxair	USA
AP&C	Canada
Erasteel	France

Key selection factors:

• Range of powder grades and particle sizes
• Production capacity and lead times
• Powder quality and consistency
• Compliance with medical standards
• Pricing and minimum order quantity
• Inspection, testing and QA processes

CoCrMoW Powder Handling and Safety

CoCrMoW Powder Handling

Recommendation	Reason
Avoid inhalation	To prevent lung tissue damage from fine particles
Use protective mask and gloves	Prevent accidental ingestion through nose/mouth
Handle in well ventilated areas	Reduce airborne particle circulation
Use appropriate protective clothing	Minimize skin contact
Ensure no ignition sources nearby	Powder can combust in oxygen atmosphere
Follow anti-static protocols	Prevent fire due to static discharge while handling
Use non-sparking tools	Avoid possibility of ignition
Store in sealed containers in cool, dry area	Prevent contamination and oxidation

Although CoCrMoW powder is relatively inert, recommended precautions should be taken for safe handling and processing.

CoCrMoW Powder Inspection and Testing

CoCrMoW Powder Testing

Test	Details
Chemical analysis	ICP spectroscopy used to verify composition
Particle size analysis	Determines particle size distribution
Apparent density	Measured using Hall flowmeter as per ASTM B212
Powder morphology	Imaging analysis via SEM to check particle shape
Flow rate testing	Determines flowability through a standardized funnel
Tap density testing	Density measured after mechanically tapping powder sample

Rigorous testing ensures compliance with specifications like ASTM F75 and consistent powder suitable for orthopedic implant manufacturing.

CoCrMoW Powder Storage and Handling

CoCrMoW Powder Storage

Factor	Effect
Air, oxygen	Risk of oxidation at high temperatures
Moisture	Low corrosion rate at room temperature
Organic solvents	Can absorb solvents and stain powder
Acids, alkalis	Resistant to mild acids and bases
Elevated temperatures	Increased reactivity and oxidation in air
Contamination	Can affect flowability, sintering ability

Recommendations:

• Store sealed in inert gas purged containers
• Maintain below 30°C temperature
• Avoid contact with oxidizing acids and chlorinated solvents
• Open containers only in controlled environments

With proper precautions, CoCrMoW powder exhibits excellent stability during handling and storage.

Comparison With CoCrMo Powder

CoCrMoW vs CoCrMo Powder

Parameter	CoCrMoW	CoCrMo
Density	9.2 g/cc	8.3 g/cc
Hardness	43-52 HRC	35-45 HRC
Tensile strength	1310-1650 MPa	1170-1510 MPa
Wear resistance	Excellent	Very good
Corrosion resistance	Excellent	Excellent
Biocompatibility	High	High
Cost	High	Moderate
Uses	Orthopedic implants, aerospace	Orthopedic implants, dental

• CoCrMoW has significantly higher strength and hardness
• CoCrMoW provides better wear resistance
• Both offer excellent corrosion resistance and biocompatibility
• CoCrMoW is more expensive due to W addition
• CoCrMoW preferred for knee, hip implants; CoCrMo for dentistry

The tungsten addition gives CoCrMoW superior mechanical properties than conventional CoCrMo alloys.

CoCrMoW Powder Pros and Cons

Advantages of CoCrMoW Powder:

• Excellent strength, hardness and wear resistance
• High biocompatibility and corrosion resistance
• Good high temperature properties
• Can be processed via AM or MIM techniques
• Suitable for load-bearing orthopedic implant applications
• Provides attractive aesthetic appearance

Limitations of CoCrMoW Powder:

• More expensive than CoCrMo and stainless steel powders
• Lower ductility and fracture toughness
• Requires protective atmosphere during processing
• Difficult to machine final components
• Limited joinability and weldability
• Release of Co ions raises health concerns

CoCrMoW Powder FAQs

Q: What are the main applications of CoCrMoW powder?

A: The primary applications are knee and hip joint replacement implants, dental restorations like crowns and bridges, maxillofacial implants, and aerospace components like turbine blades.

Q: How does tungsten addition improve the properties of CoCrMo alloy?

A: Tungsten significantly increases strength, hardness and wear resistance through solid solution strengthening and formation of stiff carbides. This results in excellent performance for load bearing implants.

Q: What precautions are needed when handling CoCrMoW powder?

A: Recommended precautions include using protective mask, gloves, clothing, handling in ventilated areas, avoiding ignition sources, controlling static discharge, using non-sparking tools, and storing sealed containers in a cool, dry place.

Q: What are the key differences between CoCrMoW grades for medical and industrial uses?

A: Medical grades have higher purity, lower impurities, controlled particle size distribution, undergo more rigorous testing, and are produced under stringent quality control to meet standards for biomedical implants.