MNEX (Cost-Effective copper alloy) ｜Copper & Copper Alloy Business Unit, MITSUBISHI MATERIALS

Standard No.

CDA: C41125

Next-generation Cost-Effective copper alloy. The world's first Cu-Zn based alloy contributing to the excellent terminal performance and low cost. It is an innovative material that overcomes the deterioration of the spring properties under the high temperature or corrosive environment which was a weak point of the conventional Cu-Zn system. It contributes to the demonstration of the excellent terminal performance and low cost.

Positioning of Alloy

A copper alloy for automotive general purpose terminals. When it is excellent in the strength and the bending workability, it also has stress relaxation resistance characteristics. It has characteristics that can be applied to various applications.

Main features

Excellent in balance between strength · bending workability · conductivity
Excellent resistance to stress relaxation
Excellent resistance to stress in corrosion cracking
Excellent cost effectiveness
Possible to process reflow-Sn plating with excellent surface quality and whisker resistance

Main applications

In-vehicle terminals, consumer terminals, bus bars, spring materials, press-fit terminals

Chemical composition

(Weight %)

Zn	Ni	Sn	Fe	P	Cu
10	0.6	0.6	0.01	0.04	Rem.

* Including inevitable impurities and trace additive elements

Physical properties

The physical properties of MNEX 10 are as follows.

Property	Representative Value
Specific Gravity (297K)	8.8
Coefficient of Thermal Expansion (×10 /K : 293～573 K)	18.4
Thermal Conductivity (W/(m・K) : 293 K)	138
Volume Resistivity (µΩm : 293 K)	0.057
Electrical Conductivity (%IACS : 293 K)	30
Modulus of Elasticity (kN/mm^２: 293 K)	123

Mechanical properties

The mechanical properties of MNEX 10 are as follows.

	Temper		Typical Values
	H	EH	H	EH
Tensile Strength (N/mm^２)	500〜600	550〜650	541	580
0.2% Yield Strength (N/mm^２)	450〜550	500〜600	508	546
Elongation (%)	7Min.	3Min.	11	10
Elastic Limit^※1 Kb_0.1(N/mm^２)	(350Min.)	(400Min.)	(493)	(589)
Vickers Hardness^※2 (HV)	(150〜190)	(160〜210)	(168)	(182)

※1 sampling direction ; T.D.
※1,2 reference value

Stress relaxation resistance

The residual stress ratio of MNEX 10 is shown on the right. MNEX 10 has excellent stress relaxation characteristics among copper alloys and has extremely high reliability as a terminal material.

Exposure temperature: 150℃ Good Way (bending axis perpendicular to rolling direction)
Bending stress: 0.2% of 80% proof stress

Bending workability

The bending workability of MNEX 10 is as follows.

Temper	Sampling Direction (to the rolling direction)	Bending Inside Radius (mm) R							Evaluation
Temper	Sampling Direction (to the rolling direction)	0.0	0.1	0.125	0.15	0.2	0.25	0.40	R/t
H	0°:(Good Way)	△	○	○	○	○	◎	◎	0.0
H	90°:(Bad way)	△	○	○	○	○	◎	◎	0.0
EH	0°:(Good Way)	△	△	△	○	○	○	◎	0.0
EH	90°:(Bad way)	▲	▲	△	△	△	△	○	0.5

Method of evaluation: ◎Good (Acceptance)、○Minor rough surface (Acceptance)、△Major rough surface (Acceptance)、▲Minor crack (Rejection)、×Major crack (Rejection)

Fatigue property

MNEX 10 has equivalent or higher fatigue characteristics than phosphor bronze for spring and brass.

Copper & Copper Alloy Business

Copper & Copper Alloy Business

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