METHOD FOR METALLIZING THE INNER FACE OF A TUBE MADE OF A CERAMIC OR A CERAMIC MATRIX COMPOSITE

Abstract

A method for metallizing the inner face of a tube made of a ceramic or a ceramic matrix composite, including at least a step of plating a metallic tube on the inner face of the ceramic or ceramic matrix composite tube, and wherein the plating comprises a creep of the metallic tube by applying to this tube an internal pressure and a heating, the creep resulting in an increase in the outer diameter of the metallic tube until the outer face of the metallic tube presses against the inner face of the ceramic or ceramic matrix composite tube. A method for manufacturing a tubular nuclear fuel cladding implementing the metallization method.

Claims

1. A method for metallizing the inner face of a tube made of a ceramic or a ceramic matrix composite, comprising at least a step of plating a metallic tube on the inner face of the ceramic or ceramic matrix composite tube, wherein the plating comprises a creep of the metallic tube by applying to this tube an internal pressure and a heating, the creep resulting in an increase in the outer diameter of the metallic tube until the outer face of this tube plates on the inner face of the ceramic or ceramic matrix composite tube.

2. The method of claim 1, wherein the application of an internal pressure to the metallic tube comprises an isostatic pressurisation of this tube.

3. The method of claim 2, wherein the isostatic pressurisation comprises an intake of a gas.

4. The method of claim 3, wherein the gas is an inert gas.

5. The method of claim 1, wherein the heating of the metallic tube is carried out by Joule effect.

6. The method of claim 1, wherein the metallic tube is made of zirconium, titanium or an alloy thereof.

7. The method of claim 6, wherein the metallic tube is made of a zirconium alloy.

8. The method of claim 1, wherein the ceramic or ceramic matrix composite tube is a tube made of silicon carbide or a silicon carbide matrix and fibrous reinforcement composite.

9. The method of claim 8, wherein the fibrous reinforcement comprises carbon fibers, silicon carbide fibers or oxide fibers.

10. The method of claim 9, wherein the fibrous reinforcement comprises silicon carbide fibers.

11. The method of claim 1, further comprising, before the plating step, an insertion of the metallic tube into the ceramic or ceramic matrix composite tube.

12. A method for manufacturing a tubular nuclear fuel cladding, the cladding comprising a layer made of ceramic matrix composite of which the inner face is coated with a metallic layer, wherein the method comprises at least a step of implementing the metallization method of claim 1.

13. The method of claim 12, wherein the ceramic matrix composite layer forms the outer face of the cladding and the metallic layer forms the inner face of the cladding.

14. The method of claim 12, wherein the ceramic matrix composite layer is a layer made of silicon carbide matrix and silicon carbide fibers and the metallic layer is a layer made of a zirconium alloy.

15. The method of claim 12, wherein the cladding is a cladding of a nuclear fuel for a light water reactor.

16. A method for manufacturing a tubular liquid or solid gas tank or a tubular propellant tank, of which the wall comprises a layer made of ceramic or ceramic matrix composite of which the inner face is coated with a metallic layer, wherein the method comprises at least a step of implementing the metallization method of claim 1.

17. The method of claim 16, wherein the ceramic or ceramic matrix composite layer forms the outer face of the tank wall and the metallic layer forms the inner face of the tank wall.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0056] FIG. 1 is a schematic representation of the principle of creep-induced plating implemented in the method according to the invention, part A showing, in a longitudinal sectional view, a metallic tube in a ceramic or ceramic matrix composite tube before the metallic tube has been deformed by creep whereas part B shows the bilayer tubular structure obtained after creep deformation of the metallic tube; in this figure, the dimensions and relative proportions of the tubes are not representative of those that can be exhibited by the tubes in an actual scenario of implementation of the method according to the invention, for readability purposes.

[0057] FIG. 2, parts A and B, corresponds to two images taken by tomography of a bilayer tubular structure as illustrated in part B of FIG. 1, part A showing a segment of the structure in a cross-sectional view whereas part B shows a segment of the structure in a longitudinal sectional view.

[0058] FIG. 3 illustrates the results of a parametric search on the creep conditions capable of enabling a radial deformation of 0.70% by creep of Zircaloy-4 test specimen in an SiC.sub.f/SiC composite test specimen so as to fill the radial space initially existing between these test specimens; in this figure, the y-axis corresponds to the percentage of circumferential deformation, noted Ee, of the Zircaloy-4 test specimen whereas the x-axis corresponds to the application time, noted t and expressed in seconds, of the pressure and temperature conditions.

[0059] FIG. 4 illustrates the results of a profilometry metrological inspection aimed at assessing the radial deformation of tubular Zircaloy-4 test specimens before and after creep tests carried out on these test specimens alone; in this figure, the y-axis corresponds to the outer diameter of the test specimens, noted ? and expressed in mm, whereas the x-axis corresponds to the longitudinal range of the radial deformation, noted E and expressed in mm, of these test specimens.

[0060] FIG. 5 illustrates the results of a profilometry metrological inspection aimed at assessing, before and after a first series of creep tests, the radial deformation of tubular Zircaloy-4 test specimens in tubular SiC.sub.f/SiC composite test specimens; in this figure, the y-axis corresponds to the outer diameter, noted ? and expressed in mm, of the Zircaloy-4 test specimens whereas the x-axis corresponds to the longitudinal range of the radial deformation, noted E and expressed in mm, of these test specimens.

[0061] FIG. 6 is a similar figure to FIG. 5 but for a second series of creep tests carried out with different creep conditions.

DETAILED DESCRIPTION OF PARTICULAR MODES OF IMPLEMENTATION

ICreep-Induced Plating Principle:

[0062] Reference is first made to FIG. 1 which schematically illustrates the principle of creep-induced plating of a tube 10 made of a metal or a metal alloy on the inner face 14 of a tube 12 made of a ceramic or a ceramic matrix composite, the tubes 10 and 12 being viewed in this figure in a longitudinal section.

[0063] As shown by part A of FIG. 1, the tube 10, of outer diameter d1, is previously inserted into the tube 12, of inner diameter d2 greater than d1, the gap existing between d1 and d2 being, preferably, chosen such that, while making it possible to insert by sliding the tube 10 into the tube 12, it can subsequently be readily filled by creep of the tube 10. Thus, the gap is, preferably, between around ten micrometres and one millimetre.

[0064] The creep of the tube 10 is obtained under the effect of the application, on the inner face of the tube 10, of a pressure, preferably isostatic as symbolised by the rectilinear white arrows, so that this pressure and, hence, the creep are the same at all points of this tube. The application of this pressure is associated with a heating of the tube 10, symbolised by the undulating black arrows topped with 0.

[0065] By creep, the tube 10 is radially deformed such that its outer diameter d1 increases thus resulting in its outer face 16 plating on the inner face 14 of the tube 12, irreversibly, i.e. with no possible elastic return of the metal or the metal alloy forming the tube 10. As shown in part B of FIG. 1, a bilayer tubular structure 18 is thus obtained. This structure is characterised by a cohesion between the metallic layer and the ceramic or ceramic matrix composite layer as shown in the tomography images of FIG. 2.

[0066] The creep results in a flow of the metal or the metal alloy and, thereby, by a thinning of the thickness e of the wall of the tube 10 lined by an elongation of this tube as also shown by part B of FIG. 1.

IIExperimental Application of Creep-Induced Plating:

[0067] The data reported hereinafter are obtained for tubular test specimens made of Zircaloy-4 and tubular test specimens made of an SiC.sub.f/SiC composite having been prepared within the scope of an E-ATF programme.

[0068] The dimensions of these test specimens are shown in the table hereinafter.

TABLE-US-00001 Radial gap Inner ? Outer ? L to be filled Components (mm) (mm) (mm) (mm) Zircaloy-4 7.96.sup.+0.02/?0.01 8.40.sup.+0.05/?0.01 170.sup.?1 <0.030 SiC.sub.f/SiC 8.45.sup.?0.05 9.49.sup.?0.005 97.sup.?1

II.1Selection of Creep Conditions:

[0069] The creep conditions that may be suitable for obtaining a cohesion between the outer face of a Zircaloy-4 test specimen and the inner face of an SiC.sub.f/SiC composite test specimen are determined using the creep law described in reference [2], having the formula:

[00001]$\stackrel{.}{?}{}_{{?}_{\mathrm{visco}}}^i=A_i{?}_{?}^{n_i}\exp \left(-\frac{Q_i}{k_{B}T}\right)$

wherein: [0070] {dot over (?)}.sub.?.sub.visco.sup.i represents the rate of circumferential deformation considering an isochoric viscoplastic flow, [0071] ?.sub.? represents the circumferential stress, [0072] T represents the absolute temperature, [0073] k.sub.B represents the Boltzmann constant, [0074] A.sub.i, Q.sub.i and n.sub.i are coefficients of the creep law determined experimentally for a given material, [0075] i represents the phase transformation domain (i=?, ?).

[0076] The circumferential stress is related to the viscoplastic circumferential deformation ?.sub.?.sub.visco according to the following relation:

[00002]${?}_{?}=\frac{?p{D}_{m_0}}{2e_0}{\left(1+{?}_{{?}_{\mathrm{visco}}}\right)}^2$

wherein: [0077] ?.sub.? is as defined above; [0078] ?p represents the pressure differential applied to the Zircaloy-4 test specimen; [0079] D.sub.m.sub.0 represents the initial mean diameter of the Zircaloy-4 test specimen; [0080] e.sub.0 represents the initial thickness of the wall of the Zircaloy-4 test specimen.

[0081] In the application of this law, the temperature and pressure conditions are presumed to be applied uniformly on the Zircaloy-4 test specimens.

[0082] Moreover, it is taken as a postulate that the circumferential deformation to be imposed on the Zircaloy-4 test specimen must be 0.70% for the geometries in question so as to fill the radial gap initially present between the Zircaloy-4 test specimens and the SiC.sub.f/SiC composite test specimens.

[0083] FIG. 3 illustrates in the form of curves expressing the percentage of circumferential deformation, noted Ee vis as a function of time, noted t and expressed in seconds, the results obtained for five different pressure/temperature pairs, namely: [0084] a pressure of 1 MPa associated with a temperature of 700? C., [0085] a pressure of 1.5 MPa associated with a temperature of 700? C., [0086] a pressure of 2 MPa associated with a temperature of 600? C., [0087] a pressure of 2.2 MPa associated with a temperature of 720? C., and [0088] a pressure of 3 MPa associated with a temperature of 600? C.

[0089] As shown in this figure, three pressure/temperature pairs make it possible to obtain a circumferential deformation of 0.70% in less than 1000 seconds, namely: the 2.2 MPa/720? C. pair for which deformation is obtained in 42 seconds and the 3 MPa/600? C. and 1.5 MPa/700? C. pairs for which deformation is obtained in 800 seconds.

[0090] However, it is seen from uniaxial tensile tests that applying a pressure of 3 MPa is equivalent to imposing on the SiC.sub.f/SiC composite test specimens a radial stress of 56 MPa, i.e. greater than the yield strength of the composite and, therefore, capable of damaging the latter.

[0091] On the other hand, applying a pressure of 1.5 MPa or 2.2 MPa is equivalent to imposing on the SiC.sub.f/SiC composite test specimens a radial stress respectively of 28 MPa and 41 MPa, i.e. less than the yield strength of the composite and, therefore, capable of preventing any damage thereof.

[0092] Therefore, creep conditions using a pressure of 1.5 MPa, on one hand, and 2.2 MPa, on the other, are tested hereinafter.

II.2Creep Tests on Zircaloy-4 Test Specimens Alone:

[0093] Creep tests are performed on Zircaloy-4 test specimens alone, i.e. without the presence of SiC.sub.f/SiC composite test specimens, by applying a pressure of 1.5 MPa and a temperature of 700? C. for 800 seconds in order to validate these conditions experimentally.

[0094] These tests are carried out by means of a creep bench, as described in reference [2], which is adapted to grip metallic tubes. The pressure is applied uniformly on the inner face of the test specimens by intake of an inert gas whereas the test specimens are heated by Joule effect. The test specimens are disposed in an enclosure making it possible to work in a controlled atmosphere. The temperature is measured on the outer face of the test specimens by a bichromatic pyrometer, as well as inside the test specimens using a thermocouple.

[0095] A profilometry metrological inspection of the test specimens is carried out before and after the creep tests.

[0096] The results of this inspection are illustrated in FIG. 4, the dotted-line profiles corresponding to the respectively minimum, mean and maximum variations, of the outer diameter, noted ? and expressed in mm, of the test specimens before the creep tests whereas the solid-line profiles correspond to the respectively minimum, mean and maximum variations of the same diameter following the creep tests.

[0097] This figure shows that after the creep tests, a mean increase of 1.2% of the outer diameter of the Zircaloy-4 test specimen is obtained homogeneously over a longitudinal range of approximately 120 mm, this range corresponding to the part, referred to as usable part, of the Zircaloy-4 test specimens to be associated with the inner wall of the SiC.sub.f/SiC test specimens (see the respective lengths of the Zircaloy-4 test specimens and the SiC.sub.f/SiC composite test specimens presented in the table hereinabove).

II.3Creep Tests on Zircaloy-4 Test Specimens in SiC.SUB.f./SiC Composite Test Specimens:

[0098] Similar creep tests to those described in point II.2 hereinabove are carried out with the exception that these tests are carried out on Zircaloy-4 test specimens inserted into SiC.sub.f/SiC composite test specimens.

[0099] Two series of tests are carried out: [0100] a first series by applying to the Zircaloy-4 test specimens a pressure of 1.5 MPa associated with a temperature of 700? C. for 800 seconds, and [0101] a second series of tests by applying to the Zircaloy-4 test specimens a pressure of 2.2 MPa associated with a temperature of 720? C. for 1600 seconds; indeed, although FIG. 3 shows that for this pressure/temperature pair, 42 seconds are sufficient to obtain the radial deformation sought, a longer time is used in the second series of tests for comfort.

[0102] Here also, a profilometry metrological inspection of the test specimens is carried out before and after the creep tests.

First Series of Tests (1.5 MPa/700? C./800 s):

[0103] The results of the metrological inspection in this first series of tests are illustrated in FIG. 5, wherein the dotted-line profiles correspond to the respectively minimum, mean and maximum variations of the outer diameter, noted ? and expressed in mm, of the Zircaloy-4 test specimens before the creep tests whereas the solid-line profiles correspond to the mean variations of the same diameter following the creep tests. In this figure, the variations of the outer diameter of the Zircaloy-4 test specimens are shown for the entire length of these test specimens including their usable part.

[0104] This figure shows that following the creep tests, a radial deformation of 0.97% of the Zircaloy-4 test specimens is obtained for the parts of these test specimens which are not covered by a SiC.sub.f/SiC composite test specimen, which suggests that a creep-induced plating of the Zircaloy-4 test specimens at their usable part was indeed performed.

[0105] FIG. 5 also shows that the radial deformation by creep of the Zircaloy-4 test specimens has no, under the retained creep conditions, incidence on the SiC.sub.f/SiC composite test specimens, the outer diameter thereof being the same before and after the creep tests.

Second Series of Tests (2.2 MPa/720? C./1600 s):

[0106] The results of the metrological inspection in this second series of tests are illustrated in FIG. 6, wherein, here also, the dotted-line profiles correspond to the respectively minimum, mean and maximum variations of the outer diameter ? of the Zircaloy-4 test specimens before the creep tests whereas the solid-line profiles correspond to the mean variations of the same diameter following the creep tests.

[0107] This figure shows that following the creep tests, a radial deformation of up to 27% of the Zircaloy-4 test specimens is obtained for the parts of these test specimens which are not covered by a SiC.sub.f/SiC composite test specimen, which, here also, suggests that a creep-induced plating of the Zircaloy-4 test specimens at their usable part was indeed performed.

MENTIONED REFERENCES

[0108] [1] L. Duquesne, Caract?risation thermique de structures composites SiC/SiC tubulaires pour applications nucl?aires. G?nie des proc?d?s. ?cole nationale sup?rieure d'arts et m?tiersENSAM, 2015 [0109] [2] T. Forgeron, et al., Experiment and Modelling of Advanced Fuel Rod Cladding Behavior Under LOCA Conditions: Alpha-Beta Phase Transformation Kinetics and EDGAR Methodology, Zirconium in the Nuclear Industry: Twelfth International Symposium, ASTM STP, 2000, 1354, 256-278