Patent ID: 11966198
Assignee: NIVAROX-FAR S.A.
Field: Materials, metallurgy (Chemistry)
Classification: CPC G  C | IPC C  G

Claim 5:
6. A method of manufacturing a spiral spring according to claim 1, the method comprising:
producing a blank of a niobium-based alloy consisting of:
niobium: balance to 100 wt %;
titanium: from 40 wt % to 49 wt %; and
traces of elements selected from the group consisting of O, H, C, Fe, Ta, N, Ni, Si, Cu, and Al, wherein each of the elements is present in an amount between 0 ppm and 1600 ppm by weight, and the total amount representing all of the elements is between 0 wt % and 0.3 wt %,
β type hardening of the blank at a given diameter, such that the titanium of the niobium-based alloy is essentially in the form of a solid solution with niobium in β phase, and a content of titanium in α phase is 5 vol % or less, and
performing at least one deformation of the blank alternating with at least one heat treatment, wherein the number of heat treatments and of deformations is limited so that the blank obtained retains a structure in which the titanium of the niobium-based alloy is essentially in the form of a solid solution with niobium in β phase, the content of titanium in α phase is 5 vol % or less and the niobium-based alloy has an elastic limit of at least 600 MPa and an elastic modulus of 100 GPa or less, and before the last heat treatment carrying out winding to form the spiral spring.