CuZn40 Powder

CuZn40 Powder Overview

CuZn40, also known as brass powder, is a copper-zinc alloy composed of 40% zinc and remainder copper. It offers an excellent combination of strength, ductility, corrosion resistance, machinability, and economical pricing making it one of the most widely used alloy powders.

CuZn40 Powder Composition

The composition of CuZn40 brass powder is:

Element	Composition
Copper (Cu)	Balance
Zinc (Zn)	39-41%

• Copper forms the primary matrix imparting ductility and corrosion resistance.
• Zinc provides solid solution strengthening and improves machinability.

This composition is referred as ‘Free machining brass’ or ‘High machinability brass’ owing to the enhancements from the 40% zinc content.

Small additions of lead up to 0.5% may be present in some varieties to further augment machinability. Lead-free CuZn40 powder is preferred for food contact and environmental safety.

Properties of CuZn40 Powder

CuZn40 powder offers a versatile mix of properties making suitable for wide usage across industries:

Property	Value
Density	8.4-8.8 g/cm3
Melting Point	900-920°C
Electrical Conductivity	26% IACS
Thermal Conductivity	120 W/m-K
Coefficient of Thermal Expansion	20 x 10<sup>-6</sup> /°C
Modulus of Elasticity	97-110 GPa
Tensile Strength	330-550 MPa
Elongation	15-40%
Hardness	80-90 Brinell
Thermal Stability	Good, up to 400°C

• Excellent formability and ductility – High elongation enables extensive cold working and forming.
• Good machinability and finish – Reduction in machining forces compared to copper alloys with lower or no zinc.
• High strength – Up to twice the strength of copper due to zinc in solid solution.
• Corrosion resistant -Forms protective oxide layer in atmosphere. Better than plain carbon steels.
• Non-magnetic – Suitable for applications requiring minimal magnetic properties.
• Good thermal stability – Dimensions stable during thermal cycling up to 400°C range.

This combination of strength, ductility, thermal and electrical properties makes CuZn40 suitable for wide usage in electrical, automotive, marine and industrial applications.

Applications of CuZn40 Powder

The versatile properties of CuZn40 powder make suitable for the following applications:

Application	Benefits
Electrical connectors	High strength, good conductivity, corrosion resistance
Fasteners, gears	Good machinability, wear resistance
Bearings, bushings	Compatible with rotating shafts, good lubricity
Welding rods	Compatibility with steel, good brazeability
Decorative parts	Attractive gold color, good finish
Thermal management	Higher thermal conductivity than steels

• Electrical connectors and contacts – Used widely in pins, connectors due to strength, conductivity and cost advantage over alternatives.
• Machined parts – Suitable for nuts, bolts, gears, valves etc. owing to excellent machinability.
• Bearings and bushings – Compatible with steel shafts while providing good wear resistance and lubricity.
• Welding consumables – Popular in Cu-Zn filler rods and brazing alloys to join steel components.
• Decorative accessories – Provides aesthetic gold finish for decorative parts and jewelry.
• Thermal components – Used in heat exchangers and thermal management parts leveraging its higher thermal conductivity.

CuZn40 powder is widely accepted across industrial sectors owing to its versatile properties, performance and economical pricing.

CuZn40 Powder Specifications

CuZn40 powder is available in various size ranges, shapes and purity levels:

Specification	Options
Particle size distribution	10 – 150 microns
Mean particle size	20, 45, 60, 100 microns
Powder shape	Irregular, spherical
Apparent density	Up to 75% theoretical
Flow rate	Up to 25 s/50g
Purity	Up to 99.9%
Alloy variants	CuZn10, CuZn30, CuZn37

• Smaller particle sizes below 45 microns allow greater densification but reduces flowability.
• Spherical powder provides better flow and packing density suited for additive manufacturing.
• Higher apparent density and flow rates improve powder handling and processing.
• High purity variants available for more demanding applications.
• Range of zinc levels between 10-40% available for varying strength-ductility.

CuZn40 powder can be customized in terms of particle size, shape, density, flow characteristics and alloy composition based on application requirements.

Consolidation Methods for CuZn40 powder

CuZn40 powder can be processed into full density components using techniques like:

Method	Details
Compaction + Sintering	Older economical method with shape limits.
Metal Injection Molding (MIM)	Net shape parts with excellent precision and surface finish.
Additive Manufacturing	Direct printing of complex, dense parts from CAD models.
Hot Extrusion	For simple, axisymmetric shapes like rods and tubes.
Roll compaction	For sheet and strips requiring good ductility.

• Pressing followed by sintering is commonly used but requires secondary processing for full densification.
• MIM offers highest precision and surface finish but needs high volumes to justify tooling costs.
• Additive manufacturing methods like binder jetting and fused deposition modeling are gaining popularity for design flexibility.
• Extrusion and rolling well suited for simple geometries like bars, sheets etc. leveraging ductility.

The consolidation method controls final properties like density, precision, surface finish and microstructure.

Heat Treatment of CuZn40 Parts

Heat treatment of CuZn40 parts helps tailor a range of mechanical properties:

Heat Treatment	Purpose
Solution annealing	Restores ductility after cold working
Stress relieving	Removes residual stresses
Precipitation hardening	Strengthening by aging after solutionizing

• Annealing at 700-900°C followed by slow cooling softens the alloy by removing effects of cold work allowing further forming.
• Low temperature age hardening in 150-350°C range causes precipitation of copper-rich phase increasing strength up to 50% but with loss of ductility.
• Stress relieving around 300-500°C helps reduce residual stresses from prior shaping.

Heat treatment expands the versatility of CuZn40 alloy by enabling property enhancements as per application needs.

Comparison of CuZn40 with Alternatives

Here is how CuZn40 compares to other popular copper alloy powders:

Alloy	CuZn40	CuSn6	CuNi18Zn20	Bronze
Strength	High	Medium	Highest	Medium
Ductility	High	Medium	Low	Medium
Corrosion Resistance	Good	Excellent	Excellent	Excellent
Thermal Conductivity	120 W/m-K	50 W/m-K	20 W/m-K	60 W/m-K
Cost	Low	High	High	Medium

• CuSn6 has superior corrosion resistance but lower strength and thermal conductivity. More expensive.
• CuNi18Zn20 has the highest strength but lowest ductility and thermal conductivity.
• Bronzes like CuSn10 offer excellent corrosion resistance but only moderate strength.
• CuZn40 provides the most balanced overall properties and has the lowest cost.

Owing to its well-rounded properties, excellent formability, machinability and low cost, CuZn40 is the most popular copper alloy powder for wide usage across industrial segments.

CuZn40 Powder Manufacturers

CuZn40 powder is produced in high volumes globally by major metal powder producers:

Manufacturer	Country
Hoganas	Sweden
CNPC	China
Miyou Group	China
GKN Hoeganaes	USA
Jien Nickel	Taiwan
SCM Metal Products	Japan

Reputable manufacturers have stringent quality control and conform to international standards for composition, particle size distribution, apparent density and impurity levels.

They can customize CuZn40 powder compositions and attributes like particle shape, density, flow rates etc. based on customer requirements for their specific application.

CuZn40 Powder Pricing

As a widely produced commercial alloy powder, CuZn40 is quite economical. Indicative pricing is:

Powder Type	Particle Size	Price ($/kg)
For pressing	Under 150 microns	$5-15
For sintering	45-150 microns	$8-20
For MIM	10-20 microns	$12-25
For AM	15-45 microns	$15-30
High purity	Up to 5 microns	$25-40

• Irregular shape powder for pressing and sintering is most economical.
• Spherical powder for MIM and AM is costlier due to gas atomization process.
• Smaller particle sizes and high purity grades attract price premium.
• Large volume orders in tons can further reduce per-kilogram pricing.

CuZn40 powder is competitively priced owing to its broad commercial usage allowing economical production in high volumes.

Health and Safety Precautions for CuZn40 Powder

Like any fine metal powder, CuZn40 powder requires safe handling:

Hazard	Precautions	PPE
Inhalation	Avoid breathing powder dust. Ensure ventilation	Respirator mask
Skin contact	Wear gloves. Wash after contact.	Gloves
Eye contact	Wear safety glasses. Rinse if contacted.	Safety goggles
Ingestion	Avoid hand-mouth contact. Wash hands.	–
Dust explosion	Avoid powder clouds. Ground equipment.	–

• Use PPE – respirator, gloves, goggles when handling powder.
• Avoid skin contact. Wash after exposure.
• Store sealed containers away from sparks, flames.
• Ensure proper ventilation and dust collection.
• Refer SDS and local regulations for complete safety guidelines.

Proper precautions and PPE during storage, handling and processing minimize health and safety risks.

Inspection and Testing of CuZn40 Powder

To ensure quality, CuZn40 powder should be tested as follows:

Parameter	Method	Specification
Chemical composition	Combustion analysis or XRF	Zn 40% ± 1%, Pb < 1000 ppm
Particle size distribution	Sieving, laser diffraction	D10, D50, D90 within range
Apparent density	Hall flowmeter	Minimum specified
Flow rate	Hall flowmeter	Maximum specified
Impurities	ICP or LECO analysis	Low oxygen and nitrogen

Routine testing as per ASTM standards ensures consistency in production and high quality powder suitable for end applications.

Buyers must insist on quality certificates from reputable manufacturers. In-house testing periodically is also recommended.

FAQs

Q. What is CuZn40 used for?

A. CuZn40 finds wide usage in electrical connectors, plumbing fittings, gears, decorative parts etc. leveraging its strength, ductility, corrosion resistance and machinability.

Q. What is the difference between regular and leaded brass alloy?

A. Leaded brass contains a small amount of lead up to 3% to enhance machinability while regular brass is lead-free. Lead-free is preferred for food contact and environmental safety reasons.

Q. Does CuZn40 require heat treatment?

A. Optional heat treatment can be done to soften and restore ductility via annealing or to strengthen by precipitation hardening.

Q. What methods are used to make parts from CuZn40 powder?

A. Compaction followed by sintering, metal injection molding and additive manufacturing processes like binder jetting and FDM are popular techniques to consolidate CuZn40 powder into dense components.

Q. Is CuZn40 powder safe to handle?

A. Like any fine metal powder, precautions should be taken to avoid inhalation and skin contact. Proper ventilation, PPE and safe handling procedures minimize risks.