MITSUBISHI MATERIALSCopper & Copper Alloy Business

MITSUBISHI MATERIALSCopper & Copper Alloy Business

Japanese

Products information

MAX SeriesCorson alloy

Standard No.
CDA
C64725(MAX251(C))
CDA
C64727(MAX375)

MAX series is excellent in strength,electrical conductivity and workability.
We can provide the those properties by our original technology.

Positioning of Alloy

Corson alloys has an excellent balance of strength and electrical conductivity due to Ni -Si intermetallic compounds precipitated in the matrix.


We have prepared the several MAX series according to application.

Main applications

Automotive terminals · connectors, consumer terminals · connector relays, IC sockets, breakers, lamp sockets, CPU sockets

MAX251 CDA64725

MAX251 has excellent properties of erectrical conductivity, strength and workability, and also that can be used as an altanative to phosphor bronze.
MAX251 has high electrical conductivity than other MAX sereis.

Positioning of Alloy

MAX251 is one of corson alloys developed by Mitsubishi Material.
It has high electrical conductivity than other MAX sereis and middle range strength.

Main features

  1. Excellent balance of strength,electrical conductivity and workablity.
  2. Excellent heat resistance
  3. Small anisotropy of mechanical properties by our original technology.
  4. Possible to process reflow-Sn plating with excellent surface quality and whisker resistance

Main applications

Small terminals, connectors, relays, sockets

Chemical composition

(Weight %)

Ni Si Sn Zn Cu
2 0.5 0.5 1 Rem.
* Including inevitable impurities and trace additive elements

Physical properties

The physical properties of MAX251 are as follows.

Property Representative Value
Specific Gravity (293K) 8.9
Coefficient of Thermal Expansion (×10-6/K:293~573K) 17.1
Thermal Conductivity
(W/(m・K):293K)
194
Volume Resistivity
(μΩm:293K)
0.038
Electrical Conductivity (%IACS:293K) 46
Modulus of Elasticity
(kN/mm : 293K)
130

Mechanical properties (sampling direction :L.D.)

  Temper
1/2H H EH SH ESH
Tensile Strength
(N/mm)
450~550 500~600 540~640 600~700 700 min.
0.2% Yield Strength
(N/mm)
390~520 440~580 480~630 540~690 650 min.
Elongation
(%)
8 min. 6 min. 4 min. 2 min. -
Elastic Limit
Kb0.1※1[kN/mm]
- - (400 min.) (440 min.) (470 min.)
Vickers Hardness※2
(HV)
(125~185) (140~200) (150~215) (165~230) (200 min.)
*1 sampling direction is T.D..
*1,*2 reference value

Stress relaxation resistance

MAX251 has excellent stress relaxation resistance than phosphor bronze(C5210) and brass (C2600).

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

Fatigue properties

The fatigue characteristics of the MAX 251 meet the level required for springs and terminals.

MAX251C CDA64725

The MAX 251C is a high-strength copper alloy which is further improved in properties by utilizing special heat treatment during the manufacturing process, not only improved in the strength but also reduced the anisotropy of the mechanical properties, and has the optimized balance between the strength and the bending workability. It has been developed for various applications due to its good workability.

Positioning of Alloy

The MAX 251C is a Corson alloy that has the improved strength and bending workability compared with conventional products through its own manufacturing process. It realizes further miniaturization of parts by obtaining the balance between the strength and the bending workability which is better than that of MAX 251. It is also possible to switch titanium copper with beryllium copper.

Main features

  1. Excellent in balance between strength · bending workability · conductivity
  2. Excellent thermal creep resistance
  3. Small anisotropy of mechanical properties due to special heat treatment
  4. Possible to process reflow-Sn plating with excellent surface quality and whisker resistance

Main applications

Small male and female terminals for Automotive, LED lamp socket, fuse terminal, small switch, consumer terminal · connector

Connectors for Automobile

Chemical composition

The chemical components of MAX251C are as follows.

(Weight %)

Ni Si Sn Zn Cu
2 0.5 0.5 1 Rem.
* Including inevitable impurities and trace additive elements

Physical properties

The physical properties of MAX251C are as follows.

Property Representative Value
Specific Gravity(293K) 8.9
Coefficient of Thermal Expansion
(×10-6/K:293~573K)
17.1
Thermal Conductivity
(W/(m・K):293K)
160
Volume Resistivity
(μΩm:293K)
0.047
Electrical Conductivity
(%IACS:293K)
37
Modulus of Elasticity
(kN/mm: 293K)
130

Mechanical properties (Sampling direction:L.D.)

The mechanical properties of MAX251C are as follows.

  Temper Typical values
1/2H H EH 1/2H H EH
Tensile Strength
(N/mm)
540~640 600~700 640~740 626 675 717
0.2% Yield Strength
(N/mm)
480~630 540~690 580~735 554 584 663
Elongation
(%)
8 5 3 17.3 14.8 11.4
Elastic Limit
Kb0.1※1[kN/mm]
- - - (477) (529) (562)
Vickers Hardness※2
(HV)
(150~215) (165~230) (180~240) (187) (199) (211)
Electrical Conductivity
[%IACS]
33 min. 40 38 38
*1 sampling direction is T.D..
*1,*2 reference value

Softing resistance

The MAX251C has sufficient heat resistance as a terminal material to be used at high temperatures.

Stress relaxation resistance

It shows that it has stress relaxation properties equalt to or greater than beryllium copper and phosphor bronze for spring.

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

Bending workability

The bending workability of the MAX251C is as follows.
While having high strength, it also has excellent bending workability. This can contribute to miniaturization and improvement of reliability of parts.

Temper Sampling Direction Bending Inside Radius (mm) R Evaluation R/t
(to the rolling direction) 0.0 0.1 0.125 0.15 0.2 0.25 0.4 0.6 0.8 1.0
1/2H 0°:(Good way) 0.0
90°:(Bad way) 0.0
H 0°:(Good way) 0.0
90°:(Bad way) 0.0
EH 0°:(Good way) 0.6
90°:(Bad way) 0.5
Method of evaluation: ◎Good (Acceptance)、○Minor rough surface (Acceptance)、△Major rough surface (Acceptance)、▲Minor crack (Rejection)、×Major crack (Rejection)

Inquiry

Rolled product Sales Dept.

TEL:+81-3-5252-4981

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