Precision C is a heat treatable Nickel-Iron Alloy used in critical diaphragm applications, such as, metal diaphragms for aerospace sensors and burst discs. The alloy composition provides a unique constant elastic modulus value over a temperature range of -50ºF to 150ºF.
Precision C can be readily formed from the annealed temper. It has a work hardening rate similar to austenitic stainless steel. The material can be joined by TIG, EB, and resistance welding as well as by brazing and soft solder technique. The heat treatment of Precision C can be adjusted to produce the desired value for the thermoelastic coefficient at or near zero. The elevated strength in the heat treated temper results in low mechanical hysteresis and low drift.
Available Sizes:
Precision C is available from Hamilton Precision Metals as strip product in thickness from 0.0005” to 0.040” (0.0127 mm to 1.016 mm) and widths up to 8.0” (203.2 mm).
The material conforms to ASM 5221 and UNS N09902.
Nominal Composition
| PRECISION C NOMINAL COMPOSITION |
| Nickel |
42%
|
| Chromium |
5.3%
|
| Titanium |
2.4%
|
| Aluminum |
0.55%
|
| Silicon |
0.50%
|
| Manganese |
0.40%
|
| Carbon |
0.02%
|
| Iron |
Balance
|
Mechanical Properties
| PRECISION C MECHANICAL PROPERTIES |
|
ANNEALED |
ANNEAL/HEAT
TREAT 1250°F
/ 3½ HRS |
50% COLD
ROLLED |
50% C.R./HEAT
TREAT 1200°F
/ 2½ HRS |
| Ultimate Tensile Strength |
95,000 PSI |
170,000 PSI |
140,000 PSI |
200,000 PSI |
| Yield Strength (0.2% Offset) |
40,000 PSI |
110,000 PSI |
130,000 PSI |
180,000 PSI |
| Elongation in 2” * |
35% |
18% |
6% |
7% |
| Proportional Limit |
15,000 PSI |
65,000 PSI |
55,000 PSI |
110,000 PSI |
| Rockwell Hardness |
B75 |
RC33 |
RC29 |
RC42 |
| Tensile Modulus of Elasticity |
25 x 106 PSI |
26 x 106 PSI |
25.5 x 106 PSI |
28 x 106 PSI |
| Poisson’s Ratio |
0.33 |
- |
- |
- |
The measured elongation will be less as thickness decreases to 0.004” and less.
These values may be adjusted by control of process variables – consult HPM for desired values.
Physical Properties
| PRECISION C PHYSICAL PROPERTIES |
| Density (Heat Treated) |
0.294 lbs/cu.in. |
| Melting Point (Approx.) |
1455° C |
| Electrical Resistivity |
102 Microhm·cm |
| Thermal Expansion Coefficient (-45°C to 65°C) |
8.1 x 10-6/°C |
| Thermal Conductivity @ R.T. |
13.0W/m·K |
| Curie Temperature (Heat Treated) |
193°C Approx. |
| Magnetic Attraction |
Yes |
Typical values to guide alloy selection but are not a guarantee of minimum or maximum