HPM® 80/20 A is a resistance alloy used in electric heating applications. It is recommended for use in dry air applications up to 2150°F with good hot strength. Such as, flexible metal foil heaters and airbag igniters.
The alloy forms rather well and has good welding characteristic. Caution should be used to avoid extended exposure to elevated temperature in marginally oxidizing or
partially reducing atmospheres as it would be susceptible to “green rot” corrosion, carburization and sulfurization.
Available Sizes:
HPM® 80/20 A is available from Hamilton Precision Metals as strip product in thicknesses from 0.0005” to 0.050” (0.0127 mm to 1.27 mm) and width up to 12” (304.8 mm).
The material conforms to ASTM B-344. Foil product may be supplied in thickness to 0.0001” (0.00254 mm) in width up to 4.0” (101.6 mm).
Nominal Composition
| HPM® 80/20 A NOMINAL COMPOSITION |
| Chromium |
19.5%
|
| Silicon |
1.25%
|
| Iron |
0.50%
|
| Manganese |
0.40%
|
| Nickel |
Balance
|
Mechanical Properties
| HPM® 80/20 A MECHANICAL PROPERTIES |
|
ANNEALED |
COLD ROLLED |
| Ultimate Tensile Strength |
105,000 PSI |
190,000 PSI
|
| Yield Strength (0.2% Offset) |
50,000 PSI |
185,000 PSI
|
| Elongation in 2” * |
35%
|
1%
|
| Modulus of Elasticity (Tension) |
31 X 106
PSI
|
- |
*The measured elongation will be less as thickness decreases to 0.002” and less.
These values may be adjusted by control of process variables – consult HPM for desired values.
Physical Properties
| HPM® 80/20 A PHYSICAL PROPERTIES |
| Density |
0.304 lbs./cu.in. |
| Melting Point (Approx. |
1400°C |
| Electrical Resistivity @ R.T. |
108 Microhm·cm |
|
Temperature Coefficient of Resistivity (TCR) (25° to 105°C)
|
100 ppm/°C
|
| Thermal Expansion Coefficient (20° to 100°C) |
13.4 x 10-6/°C
|
| Thermal Conductivity @ 100°C |
13.4 W/m·K
|
| Magnetic Attraction |
None |
| Specific Heat |
0.104 gram· cal./°C |
Typical values to guide alloy selection but are not a guarantee of minimum or maximum.