Bonding Invar

Invar is an iron-nickel alloy (typically 64% iron and 36% nickel), which offers an extremely low coefficient of thermal expansion (CTE). For some grades of Invar, the CTE can be as low as 1 ppm/C. One of the key properties of Invar is superior dimensional stability under varying temperature conditions. Therefore, it is mainly used in precision instruments in various industries. Usages include:

• Laser systems
• Temperature regulators
• Scientific instruments
• Positioning devices
• Metrology devices
• High voltage transmission lines
• Seismic creep gauges

Read our guide to learn more about proper surface preparation for bonding metals.

Consideration for Bonding Invar--Low Coefficient of Thermal Expansion

Main products for bonding invar include EP21TCHT-1 and EP30LTE-LO. Two component, thermally conductive, electrically insulative Master Bond EP21TCHT-1 is serviceable from 4K to 400F. This thixotropic paste is formulated to cure at ambient temperatures and meets NASA low outgassing requirements. Low viscosity EP30LTE-LO has superior dimensional stability. It exhibits excellent thermal conductivity, high bond strength, ultra low CTE and low outgassing properties.