MSP Series (Cu-Mg alloy)｜Copper & Copper Alloy Business Unit, MITSUBISHI MATERIALS

Standard No.

CDA: C18665（MSP1）CDA: C18670（MSP5）CDA: C18661（MSP8）

MSP Series of high-performance are solid solution strengthened Cu-Mg alloys. The lineup includes MSP1, which has been well received by customers and utilized for many years in electrical terminals for automotive applications, bus bars and relays; MSP5, which offers higher strength, bendability and low specific gravity making it ideal for use in compact-sized terminals; and MSP8, which offers superior electrical conductivity and excellent stress relaxation resistance that make it ideal for use in high-voltage, high-current applications such as bus bars and high-voltage terminals. In these ways, the series contributes to the advancement of electronics used in automobiles and other applications.

Positioning of alloys

MSP1　（CDA No:C18665）

MSP1 has been widely used as a copper alloy for terminals, and its stable quality, characteristics, and supply network make it preferred by many users. It is our No. 1 global alloy, for which we have obtained CDA No. and established a supply network in 3 regions (North America, Europe, Asia). MSP1 is also adopted for use in high-voltage terminals in EVs and PHEVs.

Positioning of alloy

MSP1 has been used for various parts such as connectors and busbars for automotive (ICE and xEV ) , moving contacts for relay , due to its excellent character, quality and supply network.
MSP1 is a global copper alloy with CDA No..
We can supply MSP1 to 3 regions(North America,Europe,Asia)

Main features

Good electrical conductivity and strength
Excellent stress relaxation resistance
Excellent stress corrosion cracking resistance
Excellent fatigue characteristics
Conforms to Class JC300 of the Japan Automobile Standards Organization's standard (JASO D 620)
Possible to process reflow-Sn plating with excellent surface quality and whisker resistance

Main applications

Terminals (for automotive applications), relays (moveable piece), spring materials for contacts, bus bars, breakers, battery terminals, fuse terminals, compact switches, electrical conductive parts in lithium ion batteries, junction boxes and relay boxes

Chemical composition

The chemical compositions of MSP1 are as follows.

(Weight %)

Mg	P	Cu
0.7	0.005	Rem.^*

* Including inevitable impurities and trace additive elements.

Physical properties

The physical properties of MSP1 are as follows.

Property	Representative Value
Specific Gravity (297K)	8.8
Coefficient of Thermal Expansion (×10^-6/K : 293〜573 K)	17.3
Thermal Conductivity (W/(m・K) : 293 K)	264
Volume Resistivity (µΩm : 293 K)	0.027
Electrical Conductivity (%IACS : 293 K)	63
Modulus of Elasticity (kN/mm² : 293 K)	125

Mechanical properties

The mechanical properties of MSP1 are as follows.

	Temper					Typical value
	1/4H	1/2H	H	EH	SH	1/4H	1/2H	H	EH
Tensile Strength (N/mm²)	365〜450	420〜510	480〜570	540〜630	590min.	399	459	530	585
0.2% Yield Strength (N/mm²)	300〜410	370〜480	440〜550	490〜620	540min.	328	432	494	560
Elongation (%)	15min.	10min.	7min.	5min.	-	25	15	11	8
Elastic Limit^*1 Kb_0.1(N/mm²)	-	-	-	-	-	(290)	(349)	(397)	(424)
Vickers Hardness^*2 (HV)	(90 〜140)	(120 〜170)	(150 〜190)	(170 〜210)	(180min.)	(126)	(144)	(162)	(178)

*1: Sampling direction perpendicular to the rolling direction
*1, 2: Reference values

Softening resistance

The Softening resistance of MSP1 is shown on the right.

MSP1 has sufficient Softening resistance for use as a terminal material, and as a spring material. It is especially suitable as an alternative to phosphor bronze.

Stress relaxation resistance

The stress relaxation resistance of MSP1 are shown on the right.

MSP1 has excellent stress relaxation resistance among copper alloys and has extremely high reliability as a terminal material

Exposure temperature: 150℃
Sampling direction: Parallel to the rolling direction
Bending stress: 80% of 0.2% yield strength

Bending workability

The bending workability of MSP1 is as follows.

MSP1 has not only an excellent balance of strength and conductivity, but also good bending workability, and can thus contribute to the miniaturization of various parts.

Temper	Sampling direction (to the rolling direction)	Bending Inside Radius (mm) R										Evaluation R/t
Temper	Sampling direction (to the rolling direction)	0.0	0.1	0.125	0.15	0.2	0.25	0.4	0.6	0.8	1.0	Evaluation R/t
1/2H	0°:(Good way)	○	○	○	○	◎	◎	◎	◎	◎	◎	0.0
1/2H	90°:(Bad way)	△	△	○	○	○	○	◎	◎	◎	◎	0.0
H	0°:(Good way)	△	○	○	○	○	○	◎	◎	◎	◎	0.0
H	90°:(Bad way)	▲	△	△	△	○	○	○	◎	◎	◎	0.3
EH	0°:(Good way)	△	△	△	△	△	○	○	◎	◎	◎	0.0
EH	90°:(Bad way)	▲	▲	▲	▲	▲	△	△	◎	◎	◎	0.8

Evaluation criteria:◎good (pass),○minor rough surface (pass),△rough surface (pass),▲minor cracking (fail),×major cracking (fail)

Fatigue characteristics

The fatigue characteristics of MSP1 are shown on the right.

MSP1 has excellent fatigue characteristics as a spring material, since it can be used numerous cycles before breaking.

MSP5　（CDA No:C18670）

MSP5 is the highest strength copper alloy in the MSP Series. Its combination of proper electrical conductivity, excellent stress relaxation resistance and bendability means that it is suitable for use as a terminal material for a diverse range of electronic and electrical devices where compact size is desired. In particular, it has been evaluated highly by customers as a copper alloy for compact-sized terminals for automotive applications. It is also suitable as an alternative to Corson alloys and phosphor bronze.