ECOBRASS
Lead-free brass

The ECOBRASS is an alloy that is excellent in the lead strength, the machinability, and the corrosion resistance, while being lead-free. It is a free-cutting copper alloy that can satisfy the ELV and RoHS regulations, and make it possible to reduce the size and weight of parts by using superior characteristics.
It has been widely used around the world, and there are many examples of applications in automotive parts, electric/ electronic equipment parts, and water faucet parts.

Positioning of Alloy

The ECOBRASS is a Cd-free lead-free copper alloy which has Pb having the content of 0.09% or less as an impurity and corresponds to the ELV regulation and RoHS regulation. In addition, the alloy properties are improved by adding stable Si to human body; however, the elements and rare metals affecting large loads with respect to human bodies and environment are not added. In addition, the ECOBRASS is registered as standard in JIS standard (C6932 (bar) · CAC804 (cast)), ASTM (C69300 (bar) · C87850 (cast)) · and DIN (CW724 R (bar)) as a global material.

PAGE TOP

Main features

  • 1) Machinability and mass productivity equivalent to C3604 can be secured by adjusting cutting conditions.
  • 2) In the copper alloy, the specific gravity is small, and the strength is as high as SUS 304, and thus it is possible to reduce the size and weight of parts.
  • 3) It can solve dezincification corrosion problem and stress corrosion cracking problem.
  • 4) Excellent wear resistance as compared with that of C3604.
  • 5) Excellent hot forgeability equivalent to C3771.
  • 6) Good melt flowability and suitable for copper alloy for casting.

PAGE TOP

Main purposes of use

  • 1) In automotive parts, excellent ELV regulatory compliance, high strength, machinability, and wear resistance are emphasized.
  • 2) In electrical and electronic parts, RoHS regulatory compliance, high strength, machinability are emphasized.
  • 3) In water faucet parts, NSF certifiablity, Ni regulatory compliance, Pb regulatory compliance, forgeability, castability, and machinability are emphasized.

PAGE TOP

Chemical composition

The chemical components of ECOBRASS are as follows.

(Weight %)
Cu Si Zn Pb P
75.5 3.0 Rem. ≤0.09 0.1

* Including inevitable impurities and trace additive elements

PAGE TOP

Physical properties

The physical properties of ECOBRASS are as follows.

Property ECOBRASS C3604 CAC406
Specific Gravity
g/cm3
8.3 8.5 8.8
Thermal Conductivity
W/m・K
45 130 70
Electrical Conductivity
%IACS
8 26 15
Coefficient of Thermal Expansion
×10-6/℃
20 21 18
Liquidus temperature
890 885 860
Solidus temperature
855 900 1010

PAGE TOP

Mechanical properties (Actual example: LD direction)

The mechanical properties of ECOBRASS are as follows.

Rod/Bar
Property ECOBRASS C3604
Tensile Strength
MPa
540~700 380~490
0.2% Yield Strength
MPa
250~550 150~350
Elongation
%
15~40 15~40
Hardness
HV
150~220 100~150
Cast* Representative value
Property ECOBRASS* CAC406*
Tensile Strength
MPa
400 220
0.2% Yield Strength
MPa
170 -
Elongation
%
20 15

PAGE TOP

Machinability

Regarding C3604, the stress concentrates on Pb particles which are soft and has low melting point, and chips are cut off.
On the other hand, ECOBRASS consists of three phases of α, κ, and γ, and the stress concentrates on hard κ and γ phases at the time of cutting, and the chips are cut off.

Mechanism of the machinability

graph

  • Dry cutting: cutting speed 150mm/min, cutting depth 1.5mm, feed speed 0.1mm, nose R 0.4mm

PAGE TOP

Characteristics of dezincification resistance

The dezincification corrosion resistance of ECOBRASS is indicated.
Unlike traditional brass, ECOBRASS is strong against dezincification corrosion, and thus the users can use it safely with faucet parts and the like.

ISO6509 Dezincification test (μm)
Alloy Maximum corrosion depth Average corrosion depth
ECOBRASS Rod/Bar 20 <10
ECOBRASS Forging 20 <10
ECOBRASS Cast 15 <10
C3604 Rod/Bar 1000 900
C3771 Forging 900 800
CAC406 Sand Casting <10 <10

PAGE TOP

Characteristics of stress relaxation resistance

The crack generation time was compared by using a method based on the JIS H 3250 time crack test.
C3604 · C3771 will crack in 2 hours; whereas the ECOBRASS can be maintained for longer than 10 days.

Characteristics of stress relaxation resistance

graph

PAGE TOP

Wear resistance

In the Amsler wear test under lubrication, comparing the wear loss of ECOBRASS with C3604 is performed.
The wear loss of ECOBRASS is only 1/50 as compared with C3604, and excellent wear resistance can be confirmed.

Abrasion test

photo Abrasion test procedure
photo Abrasion test result

PAGE TOP

Inquiry

Sales Headquarters Sales Dept. Ⅱ Group Ⅱ

Please inquire here for any questions.

PAGE TOP