COMPOSITE MATERIAL WITH INVAR PROPERTIES Russian patent published in 2019 - IPC C22C1/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy, in particular to invar alloys and compositions, characterized by the value of the coefficient of linear thermal expansion (CLTE), not exceeding 2 × 10^-6 K^-1 in the working temperature range, and can be used in instrument making, radio electronics, aviation and aerospace, laser and cryogenic engineering. Composite material with invar properties contains a functional metal with an average CLTE value not exceeding 13 × 10^-5 K^-1 in the range of temperatures 4.5–32 K or 3.22 × 10^-5 K^-1 in the temperature range of 32–250 K, and a compound with negative CLTE, while a samarium-based valence-unstable compound (VUC) is used as a compound with negative CLTE, the quantitative ratio of the composite components is determined from the Turner condition: (α_ƒV_ƒK_ƒ + α_mV_mK_m) / (V_ƒK_ƒ + V_mK_m) = 0, where: α_m – CLTE functional metal, α_ƒ – CLTE valence-unstable compound, V_m and V_ƒ – volume fractions of metal and VUC, respectively; K_m and K_ƒ – bulk moduli of metal and VUC, respectively.

EFFECT: invention is directed to the creation of a composite material with a CLTE close to zero in the temperature range up to 250 K while preserving in the composite the physical properties inherent in the metal component.

3 cl, 2 dwg, 2 tbl