The small niobium addition refines grain structure and improves hot workability. | Property | Value | |----------|-------| | Density | 0.318 lb/in³ (8.80 g/cm³) | | Electrical Conductivity | 6–10% IACS | | Thermal Conductivity | 25–35 W/m·K (at 20°C) | | Modulus of Elasticity | 18–19 Msi (124–131 GPa) | | Melting Range | 1900–2050°F (1040–1120°C) | | Magnetic Permeability | < 1.01 (non-magnetic) | 4. Mechanical Properties (by Temper) C72900 is available in several tempers, with AT (Age Hardened, Turned) and XT (Extreme Temper, cold worked + aged) being most common.
1. Overview & Designation UNS C72900 is a copper-nickel-tin (CuNiSn) spinodal alloy. It is often marketed under trade names such as ToughMet® 3 (produced by Materion) and is also referred to as CX95 in some specifications.
Unlike beryllium copper (C17200), C72900 is beryllium-free , making it safer to handle in manufacturing (no toxic beryllium dust) while achieving comparable or superior performance in certain applications. 2. Chemical Composition (Nominal) | Element | Weight % | |---------|-----------| | Copper (Cu) | Balance (~77%) | | Nickel (Ni) | 14.5 – 15.5% | | Tin (Sn) | 7.5 – 8.5% | | Niobium (Nb) | 0.1 – 0.3% | | Manganese (Mn) | ≤ 0.3% | | Others | ≤ 0.5% total |
