The γ’ phase is a cubic L12-structure Ni3(Al, Ti, Ta, Nb) phase that produces cuboidal precipitates. Superalloys often have a high (60-75%) volume fraction of γ’ precipitates. γ’ precipitates are coherent with the parent γ phase, and are resistant to shearing due to the development of an anti-phase boundary when the precipitate is sheared. The γ” phase is a tetragonal Ni3Nb or Ni3V structure. The γ” phase, however, is unstable above 650 °C, so γ” is less commonly used as a strengthening phase in high temperature applications. Carbides are also used in polycrystalline superalloys to inhibit grain boundary sliding.