DIN 17745 NiFe47Cr Alloy – Precision Thermal Expansion for High‑Performance Seals

The expansion material NiFe47Cr with the material number 2.4486 is an alloy with controlled thermal expansion and possesses a relatively low thermal expansion up to approximately 450 °C. (Temperature interval RT to 400 °C: coefficient of thermal expansion 10.0 to 10.8 10^-6 K^-1). Its expansion properties largely correspond to those of soft glass of the lead lime or sodium lime type up to the annealing temperature. Application for sealings in soft glasses, especially lead glasses, particularly for anode cavity caps in cathode-ray television tubes. The alloy is of relatively good durability at normal temperatures in air with normal weather conditions as well as in fresh water and sea water. Application as welding filler material, too. The material is well weldable by using the tungsten inert-gas method.

Properties

General

Property	Temperature	Value
Density	20.0 °C	8.2 g/cm³

Mechanical

Property	Temperature	Value	Comment
Elastic modulus	20.0 °C	170 GPa
Elongation	20.0 °C	3 - 35 %
Hardness, Brinell	20.0 °C	120 - 280 [-]
Poisson's ratio	23.0 °C	0.28 [-]	Typical for Nickel Iron Alloy
Tensile strength	20.0 °C	510 - 950 MPa
Yield strength Rp0.2	20.0 °C	200 - 930 MPa

Thermal

Property	Temperature	Value	Comment
Coefficient of thermal expansion	100.0 °C	9.1E-6 1/K
	200.0 °C	9.1E-6 1/K
	300.0 °C	9.1E-6 1/K
	350.0 °C	9.5E-6 1/K
	400.0 °C	1.03E-5 1/K
	450.0 °C	1.1E-5 1/K
	500.0 °C	1.15E-5 1/K
	600.0 °C	1.22E-5 1/K

Melting point		1450 °C	Typical for Nickel Iron Alloy
Specific heat capacity	20.0 °C	500 J/(kg·K)
Thermal conductivity	20.0 °C	14 W/(m·K)

Electrical

Property	Temperature	Value
Electrical resistivity	20.0 °C	9.2E-7 Ω·m

Chemical properties

Property	Value
Carbon	0.02 %
Chromium	5.5 - 6.5 %
Iron	44.5 - 47 %
Manganese	1 %
Nickel	45.18 %
Silicon	0.3 %

DIN 17470 CrAl25-5 Soft Annealed: Premium Ferritic Conductor for High‑Temperature Applications AA Standards Grade 5354: Comprehensive Material Properties

Metal