PERNIFER® 42

PERNIFER® 42 is an iron-nickel alloy (FeNi) with approximately 42% nickel were developed for applications requiring very low coefficients of thermal expansion up to 300°C. PERNIFER® 42 is used in the form of system supports for integrated circuits (lead frames), transistor base caps as well as connections to current carrying wires. In many cases the alloys are required to exhibit uniform etching characteristics or must be such that they can readily be stamped.

Heat Treatment

Prior to any thermal operation the material must be carefully degreased, as any residual greasy surface contaminants will evaporate and will result especially during the glass/ceramic metal sealing operation in the formation of small blisters at the metal – glass/ceramic interface. This is most effectively done by a cleansing thermal treatment in a humid hydrogen atmosphere at 800-1000°C for 10 minutes. Such a treatment is particularly important in the case of carbon containing alloys and where surfaces are contaminated. After such a treatment the alloy is in the soft condition.

Corrosion Resistance

At 20°C Pernifer® alloys are essentially corrosion resistant in atmospheres which are not too moist. However, under unfavorable conditions, if they are exposed for long periods of time to moist or even salty atmospheres, such as encountered in marine environments, these alloys are not corrosion resistant.

Specifications:

Werkstoff-No. 1.3917
DIN EN 17745
SEW 385
AFNOR Fe-Ni42
UNS K94101(Dumet), K94200
ASTM B 388, B 753 (T-42), F 29 (Dumet)
SAE AMS 7734, I-23011 (Class 5)

Chemical Composition (%) – DIN 17745
Ni	Cr	Fe	C	Mn	Si
41.0-43.0	–	Bal	≤0.02	≤0.70	≤0.20

Chemical Composition (%) – ASTM B753 (T-36)
Ni	Cr	Fe	C	Mn	Si	Co
42.0 nominal	≤0.50	Bal	≤0.15	≤0.60	≤0.40	≤0.50

Mechanical Properties at RT – DIN 17745
0.2% yield strength, R_p02	Tensile Strength, R_m	Elongation, A₅₀	Hardness
N/mm²/ksi	N/mm²/ksi	%	HV
Soft Annealed Deep Drawing Quality
≥ 240 / ≥ 34.8	≥ 490 / ≥ 71.1	≥ 30	130
50% Cold Formed
≥ 650 / ≥ 94.3	≥ 710 / ≥ 103.0	≥ 5	210

Physical Properties at RT
Density	Thermal Conductivity	Modulus of Elasticity	Deflection Temperature	Electrical Resistivity	Specific Heat
g/cm³	W/m•K	kN/mm²	°C	µΩ•cm	J/kg•K
8.2/td>	15	148	345	66	500

Coefficient of Thermal Expansion between 20°C [or 30°C] and T 10^-6/K — DIN 17745
50°C	100°C	150°C	200°C	300°C	400°C	450°C	500°C	550°C	600°C
Values are applicable to the soft annealed condition only
–	6.0	–	5.5	4.0-5.8	6.6 [6.3-7.2 avg. ASTM F 29]	–	8.3	–	9.7

Coefficient of Thermal Expansion between 77°F [25°C] and T 10^-6/°F — ASTM B 753 (T-36)
200°F (93°C)	300°F (149°C)	500°F (260°C)	700°F (371°C)
5.6 typical	5.4±8% specified	5.2 typical	5.4 typical

Fabrication
Melting Temperature	Max. Operating Temperature
1440°C	–