EP1337738B1 - Component, in particular hydraulic component, made of composite material and method for making same - Google Patents

Abstract

The invention concerns a component (11) such as a hydraulic component, made of composite material with organic matrix and reinforcing fibres (22-24), coated at least locally with a protective or metal reinforcement or metal-based layer. It comprises metal or metal-based fibres (21), said layer being formed by electrolytic deposition on said metal or metal-based fibres.

Description

The invention relates to a part, such as a component hydraulics, composite material with organic matrix and reinforcing fibers, and to a method of manufacturing such piece.

Hydraulic component means any organ likely to interact with a water flow and, by example, a Pelton turbine bucket, a director for a flow, a Kaplan turbine blade or a Francis type turbine wheel.

It is known, for example from WO-A-99 / 49,213 or from EP-A-0 900 283 to make the buckets of a Pelton turbine wheel made of composite plastic material. Indeed, the materials Organic matrix composites have good properties mechanical forces due, for the most part, to the weaving of reinforcement. However, these materials are difficult to exploit when they work in an environment where they are subjected to abrasion, shock or erosion by solid elements present, for example, in the flow in which they bathe. For example, in the case of a turbine Pelton used in a fall whose water is strongly loaded with mineral matter, the damage of the matrix organic and carbon fiber reinforcements is very fast, so that the lifespan of the buckets is low.

Similar problems arise with other parts which are subject to difficult conditions of use.

It is known to attempt to protect such pieces or components by applying a protective layer or metal-based reinforcement on such parts. Deposits obtained have an adhesion resulting, for the most part, from the difference in surface energy between the constituent material of the part and that constituting the protective layer. In practice, this is insufficient and a significant risk inadvertent disconnection of the protective layer relative to the part on which it is applied exists, with the risk of damage to an industrial plant and a very fast wear of the piece of material composite. In particular, such a type of deposit is not applicable to hydraulic components.

It is these problems that are particularly remedy the invention by proposing a piece of composite that is effectively protected against shocks and abrasion.

In this spirit, the invention relates to a part, in particular a hydraulic component made of composite material organic matrix and reinforcing fibers, this piece being at least locally coated with a protective layer metallic or metal-based, characterized in that includes metal or metal-based fibers, the layer of protection or reinforcement being formed by deposit electrolytic on these metal or metal-based fibers.

Thanks to the invention, it is possible to have a hanging intimacy between the material of the protective layer or reinforcement and the fiber material as far as the couple of material chosen, for the metal fibers or metal base on the one hand and the protective layer on the other on the other hand, is compatible with electrolytic deposition. In fact, electrolytic deposition probably allows to obtain a chemical bond between the material of the reinforcing fibers and the material of the protective layer, which avoids the risk of inadvertent stalling of the protective layer. In particular, the rigidity of the fastening obtained does not depend no curvature radii of the room in areas where is affixed the protective or reinforcing layer, which allows to consider deposits on sharp edges, such as median edges of the buckets of a Pelton turbine. of the bending tests have shown that breaking a piece according to the invention takes place by separating the matte or reinforcing fiber fabric and organic matter before the separation between the protective layer and the substrate on which it is affixed.

• Les fibres métalliques ou à base de métal sont disposées, pour l'essentiel, au voisinage de la surface de la pièce destinée à être revêtue de la couche de protection de renforcement. En effet, c'est au niveau de la surface de la pièce qui constitue le substrat que doit avoir lieu l'accrochage.
• Le matériau des fibres métalliques ou à base de métal comprend du cuivre, de l'alumimium, ou un alliage de ces métaux et/ou d'autres éléments métalliques.
• Le matériau de la couche de protection ou de renforcement comprend du nickel, du cobalt, du cuivre, d'autres éléments métalliques et/ou des alliages de ces éléments.
• La pièce en question est un composant hydraulique.

According to advantageous aspects of the invention, the part incorporates one or more of the following features:

• The metal or metal-based fibers are essentially disposed in the vicinity of the surface of the part to be coated with the reinforcing protective layer. Indeed, it is at the surface of the part that constitutes the substrate that must occur the attachment.
• The material of the metal or metal-based fibers comprises copper, alumimium, or an alloy of these metals and / or other metallic elements.
• The material of the protective or reinforcing layer comprises nickel, cobalt, copper, other metallic elements and / or alloys of these elements.
• The part in question is a hydraulic component.

• utiliser, dans certaines zones au moins de la pièce, des fibres métalliques ou à base de métal et
• procéder à un dépôt électrolytique de la couche de protection ou de renforcement sur ces fibres métalliques ou à base de métal.

The invention also relates to a method of manufacturing a part as described above and, more specifically, to a method which comprises the steps of:

• use, in at least some areas of the room, metal or metal-based fibers and
• electrolytically depositing the protective or reinforcing layer on these metal or metal-based fibers.

• Il consiste à isoler les fibres de renfort de la pièce située dans des zones autres que celles incluant des fibres métalliques ou à base de métal avant de procéder au dépôt électrolytique. Ceci permet de définir avec une bonne précision la géométrie de la couche de protection ou de renforcement. On peut en particulier prévoir d'isoler les fibres, autres que les fibres métalliques ou à base de métal, par application d'un vernis isolant.
• On applique, par un dépôt de type "à plasma", un élément métallique sur la couche de protection ou de renforcement après son dépôt. Cet aspect de l'invention tire parti du fait que l'accrochage obtenu entre la couche précitée et la pièce ou substrat est suffisamment intense pour permettre de supporter des éléments rapportés.
• On utilise, pour le bain électrolytique, une solution de composés métalliques incluant du nickel à une température d'environ 60°C avec une contre-électrode à base de nickel et une densité de courant de l'ordre de 4 A/dm², alors que les fibres de renfort sur lesquelles on effectue le dépôt sont réalisées dans un matériau comprenant du cuivre.

According to advantageous aspects of the invention, the method incorporates one or more of the following features:

• It consists of isolating the reinforcing fibers from the part located in areas other than those including metal or metal-based fibers before electrolytic deposition. This makes it possible to define with good accuracy the geometry of the protective layer or reinforcement. In particular, it is possible to isolate the fibers, other than the metal or metal-based fibers, by applying an insulating varnish.
• A "plasma" type deposit is applied to a metal element on the protective or reinforcing layer after it has been deposited. This aspect of the invention takes advantage of the fact that the hooking obtained between the aforementioned layer and the part or substrate is sufficiently intense to allow to support inserts.
• For the electrolytic bath, a solution of metal compounds including nickel at a temperature of about 60 ° C with a nickel-based counter electrode and a current density of about 4 A / dm ^{2 is used} . while the reinforcing fibers on which the deposition is performed are made of a material comprising copper.

• la figure 1 est une vue en perspective éclatée d'un auget de turbine Pelton conforme à l'invention ;
• la figure 2 est une vue éclatée et à plus grande échelle du détail II à la figure 1, lors d'une première étape de fabrication de l'auget de la figure 1 ;
• la figure 3 est une coupe selon la ligne III-III à la figure 1, lors d'une seconde étape de fabrication de cet auget et
• la figure 4 est une vue en plan d'un tissu de fibres de renfort utilisé dans un auget conforme à un second mode de réalisation de l'invention.

The invention will be better understood and other advantages thereof will appear more clearly in the light of the following description of two embodiments of a hydraulic component according to its principle, given solely by way of example and with reference to the accompanying drawings in which:

• Figure 1 is an exploded perspective view of a Pelton turbine bucket according to the invention;
• Figure 2 is an exploded view and on a larger scale of the detail II in Figure 1, during a first step of manufacturing the bucket of Figure 1;
• FIG. 3 is a section along the line III-III in FIG. 1, during a second manufacturing step of this bucket and
• Figure 4 is a plan view of a reinforcing fiber fabric used in a bucket according to a second embodiment of the invention.

The bucket 1 shown in Figures 1 to 3 is intended to be mounted on the rim, not shown, of a turbine wheel Pelton. This bucket 1 consists of a first skin 11 forming its intrados and a second skin 12 forming its extrados, these skins being made of composite materials with a matrix based on epoxy resin, polyester, vinylester, urethane, polyamide or poly-ether-ether-ketone and carbon-based reinforcing fibers, for example, on most of their surface. These fibers are presented under form of a fabric impregnated with resin. The geometry of the skins 11 and 12 is such that they define between them a volume in which stiffening ribs 13 are arranged.

We note 14 the median edge of the bucket 1 which is formed 11. This ridge is subjected to intense and variable friction depending on the quality of the water used to rotate the Pelton turbine. This edge is also subject to shocks because the water can be loaded with relatively large debris.

According to the invention, a protective layer 15 and reinforcing the edge 14 is provided on the skin 11.

The layer 15 is formed by electrolytic deposition located on the skin 11.

For this deposit to lead to an intimate collision of the layer 15 on the edge 14, and as is more particularly apparent FIGS. 2 and 3, where the spacing of the fibers is exaggerated in relation to reality, skin 11 includes, at level of the edge 14, reinforcing fibers 21 copper then that, in the rest of its surface, the skin 11 is reinforced by carbon fibers.

In fact, the copper reinforcing fibers 21 are woven between them and form a fabric 23 constituting the layer upper or outer skin 11 in the area of the ridge 14, while fabrics 24 of carbon fibers are superimposed in the rest of the skin thickness 11 and under the tissue 23 at the edge 14. Thus, the fibers 21 are grouped in the vicinity of the outer surface S of the skin 11, in the area of the ridge 14.

According to a not shown variant of the invention, all the reinforcing fibers used at the edge 14 could be copper fibers, in which case several layers of the type of fabric 23 would be superimposed.

According to another variant not shown of the invention, non-woven fiber mats could be used at the place fabrics 23 and 24.

As shown in FIG. 4 for a second mode of realization, it is also possible to foresee that the metal fibers 21 extend in a single direction of the fabric 23, for example, that they constitute the sons of chain over part of its width, whereas the wires of weft are constituted by carbon threads. The sons of carbon weft 22 extend both on a 23A portion of the fabric 23 in which they are woven with threads of chain 21 of copper and 23B parts of the fabric 23 in which they are woven with warp yarns 26 in carbon. Thus, the outer layer of the skin 11 of the bucket 1 is it continuous, only part of it being suitable for electrolytic deposition. In this case, the width of Part 23A is determined by width of the layer 15. The continuous nature of the fabric 23 ensures a good anchoring of the threads 21 in the structure of the skin 11.

In FIG. 4, the fiber spacing is also exaggerated to improve understanding of the drawing.

EXAMPLES

NiCl 50 g/l,

NiSo₄ 150 g/l,

H₃Po₃ 8 g/l,

H₃Po₄ 26,3 ml/l.

When the skin 11 has been molded, it is deposited on the parts 16 of this skin comprising only carbon fibers 22, namely the strips 24A in the first embodiment or the parts 23B in the second, a layer 25 of varnish insulation, before cleaning and degreasing the tissue layers 23 comprising fibers 21 and plunging the skin 11 into a bath of metal compounds with the following distribution:

NiCl 50 g / l,

NiSO ₄ 150 g / l,

H ₃ Po ₃ 8 g / l,

H ₃ Po ₄ 26.3 ml / l.

This bath is maintained at a temperature of about 60 ° C. A counter-electrode made of nickel is used and the elements are degrading and a current is applied with a density of approximately 4 A / dm ² , which makes it possible to obtain on the fabric 23 the formation of the layer 15 essentially with nickel. the resulting layer having a Vickers hardness of the order of 150 HV.

Satisfactory results were also obtained with cobalt ions in solution in the aforementioned bath, to which case the deposit obtained is Ni-Co type.

Of course, other pairs of metals can be considered for, on the one hand, metal fibers 21 and, on the other hand, the electrolyte bath, that is to say the layer protection or reinforcement 15.

• pour les fibres métalliques : cuivre, aluminium, alliages de ces métaux ou d'autres éléments métalliques
• pour la couche de protection ou de renforcement : cuivre, nickel, cobalt ou autres éléments métalliques ou alliages de ces éléments.

In particular, it is possible to use the following materials:

• for metal fibers: copper, aluminum, alloys of these metals or other metallic elements
• for the protective or reinforcing layer: copper, nickel, cobalt or other metallic elements or alloys of these elements.

The invention is not limited to a turbine trough Pelton and can be implemented with a turbine blade Kaplan, with a director, particularly at the level of their respective leading edges, and with a turbine wheel Francis, especially at the leading edges of the blades and at the exposed edges of the belt and ceiling. In In all cases, the areas to be protected are areas with low radii of curvature, which is not a problem given the intimate bonding obtained by electrolytic deposition.

Other mechanical parts can be realized thanks to to the invention, such as for example turbine blades.

Whatever the type of the part considered, the hanging intimate obtained between the protective layer or reinforcement and the substrate allows to consider supporting elements reported on this layer by deposit said "to plasma ", plasma spray type, PVD (" Power Vapor Deposition " or physical deposition), CVD ("Chemical Vapor Deposition" or chemical deposit), etc ... Indeed, the elevation localized temperature allowing the deposit is compatible with the nature of the material of the layer, without risk of damage of the piece made of composite materials. This deposit additional with plasma increases the protection thermal, protection against erosion or corrosion, even the mechanical protection.

Claims (10)

1. Part, especially a hydraulic component, made of a composite comprising an organic matrix and reinforcing fibres, the said part being plated at least locally with a metal or metal-based protective layer, characterized in that it comprises metal or metal-based fibres (21), the said layer (15) being formed by electroplating on the said metal or metal-based fibres.
2. Part according to Claim 1, characterized in that the said metal or metal-based fibres (21) are placed, for the most part, near that surface (S) of the said part (1) which is intended to be plated with the said layer (15).
3. Part according to one of the preceding claims, characterized in that the material of the said metal or metal-based fibres (21) comprises copper or aluminium, or an alloy of these metals and/or of other metallic elements.
4. Part according to one of the preceding claims, characterized. in that the material of the said layer (15) comprises nickel, cobalt or copper, or other metallic elements and/or alloys of these elements.
5. Part according to one of the preceding claims, characterized in that it is a hydraulic component (1).
6. Process for manufacturing a part, such as a hydraulic component, the said part being of a composite comprising an organic matrix and reinforcing fibres and plated, at least locally, with a metal or metal-based protective or reinforcing layer, characterized in that it comprises the steps consisting in:

   using, at least in certain regions (14) of the said part (1), metal or metal-based fibres (21); and

   electroplating the said metal or metal-based fibres with the said layer (15).
7. Process according to Claim 6, characterized in that it comprises a step consisting in insulating the reinforcing fibres (22) of the said part (1) which are in regions (16) other than that or those (14) including metal or metal-based fibres (21), before they are electroplated with the said layer (15).
8. Process according to Claim 7, characterized in that it comprises a step consisting in insulating the said fibres (22) other than the metal or metal-based fibres (21) by applying an insulating varnish (25).
9. Process according to one of Claims 6 to 8, characterized in that it comprises a step consisting in applying, by "plasma"-type deposition, a metallic element on. the said layer (15) after the electroplating with the said. layer.
10. Process according to one of Claims 6 to 9,. characterized in that it consists in using, for the electrolytic bath, a solution of nickel-containing metal compounds at a temperature of about 60°C, with a nickel counterelectrode and a current-density of around 4 A/dm², while the reinforcing fibres (21) on which the deposit is formed are made of a copper-containing material.

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