FR2691208A1 - Aircraft engine component provided with a heat dissipation and abrasion protection coating and manufacturing process. - Google Patents

Abstract

This ramjet component has an exposed surface in contact with a gas, hot and / or charged with particles; the protection of the leading edge (80) of this surface is obtained by means of a layer (82) of diamond, obtained by chemical vapor deposition, optionally covered with an overcoat (86) for protection against oxidation.

Description

"Aircraft engine component with a heat dissipation coating

  heat and abrasion protection and manufacturing process "The present invention generally relates to

  a jet engine component comprising a leading edge

  that over which a gas stream flows and, more particularly

  Such a component comprising a coating which is both a heat sink coating to provide thermal protection against a flow of hot gas and an erosion resistant coating to provide protection

  anti-abrasion against a gas stream charged with particles.

  The term "jet engine" includes turbo-charged engines

  gasoline engine, ramjet engines and ramjet engines with

  supersonic bustion Such jet engines can

  be used to propel flying vehicles

  Gas turbine turbines can also be used to pro-

  pulsating boats, tanks, to train gener-

  electrical power generators, pipeline pumping devices, or the like The components of

  jet engine which have a leading edge subjected to a

  rant gaseous hot and / or charged with particles include by

  example the blowers of gas turbine engines, the

  bes of compressors and covers of ramjet engines.

  Ramjet and ramjet engines are known for propelling aircraft to

  high speeds, supersonic or personal, higher

  res at around Mach 3 These two engine tv-es do not contain

  do not have components that rotate due to

  air unlike what happens in the mo-

  conventional gas turbine, turbojet or jet engines

  Instead, the ramjet engines used

  feels the supersonic movement of the aircraft in the atmosphere

  re to compress the air flow entering the mo-

  where it is mixed with the fuel and ignited to produce

  re combustion gases used to propel the aircraft.

  Superso- combustion statoreactors and ramjets

  are fundamentally different in structure

  and their function, since a ramjet is traditional-

  Lely designed to operate while being crossed by a fluid

  subsonic then cue the ramjet engines

  personiaue are designed to operate by being traversed by a flow of supersonic fluid The ramjets are

  typically effective in propelling aircraft at high speed

  its supersonics up to about Mach 6, while ramjet engines are designed

  to propel airplanes at speeds between

  approximately Mach 5 and approximately Mach 18, or even beyond.

  For purposes of illustration, the invention will be described

  referring to the hood of a ramjet

  Personique It should however be understood that this invention

  tion can also be used for other types of jet engines described above as well as other types of

  components of jet engine We can also refer to

  In this regard also to the following publications: Jones et al, "Toward Scramjet Aircraft", Astronautics & Aeronautics, pp 38-48, February 1978, as well as to American patents N 3 430 446 and 4 817 892 whose subject is expressly

  incorporated here for reference.

  One of the most severe design conditions

  posed to a hypersonic vehicle structure is the

  aerodynamic heating of the leading edges of the hood

  motor The nominal stagnation of heat flows can

  approach 22.7 MJ / m 2 S to 90.7 MJ / m 2 S (2,000 to 8,000 BTU / ft 2 sec) depending on the number of mach, dynamic pressure and

  the diameter of the outer leading edge which is conventional-

  between 2 f 54 mm and 6.35 mm (01 to 0.25 inches) o The curve of nominal heat flow looks like a cosine law 1 when we break the stagnation region for an angle o O to side of the leading edge for an angle a 90 (a being the angular position around the diameter of the leading edge) and the extreme heating rates are therefore very localized We obtain maximum performance of the input compression when the shock wave on the

  nose of the vehicle is swallowed by the engine giving a cap-

  maximum flow level However, the result is a type IV transient shock interaction since the oblique shock wave coming from the nose of the vehicle passes over the leading edge of the hood by striking the normal shock wave at the edge hood attack This transient situation can cause a local amplification of the nominal stagnation heat fluxes by a factor between 10 and 25 depending on the number of mach and the dynamic pressure at

  which occurs the capture of the shock wave These conditions

  transient "shock on the lip": can cause

  quer localized peaks of the heating rate of approxi-

  ron 453 MJ / m 2 S to 850 MJ / m 2 S (40 to 75 k BTU / ft 2 sec) The re-

  internal cooling of the leading edge of the hood obtained thanks to

  this to various techniques is a solution to this design problem if we could dissipate the heat accumulated on

  the leading edge surface to other unsubstantiated regions

  The present invention relates to jet engine components which are subjected to exposure to Gui gases.

  are hot and / or charged with particles The inno-

  of the jet engine includes a surface on which

  a gas flows, a surface which is covered with a layer of protective diamond deposited by chemical phase deposition

  Advantageously, the component of the combustion engine

  action has an hypersonic outer leading edge which is internally cooled and which supports the coating of

  diamond CVD Preferably, the jet engine component

  tion is the leading edge of a supersonline combustion ramjet engine cover which is covered with a layer of CVD diamond dissipating heato It will be understood, however, that different components of jet engines are, due to the definition of '' a flow path of

  hot gases in the engine design, subject to exposure

  sition to hot gases and to localized heating phenomena and that consequently they can be improved by being covered with a layer of heat-dissipating CVD diamond in accordance with the teachings of the present invention The same interest is also true for jet engine components which are subjected to gas flows charged with particles and which require protection against abrasion, effect obtained thanks to a

CVD diamond coating.

  The advantages of the present invention are that

  places a coating that is not only effective for

  heat siphon but which is also resistant to abrasion

  Another advantage is the very low coefficient of thermal expansion of the CVD diamond layer. An additional advantage is the exceptional

  hardness of the CVD diamond coating which will minimize the

  damage by wear, erosion and abrasion of the covered surface due to impact with particles carried by the air (i.e. dust, earth, water, ice,

  etc.) These and other advantages will become apparent

  lemenit to the skilled person based on the description

  following taken in conjunction with the accompanying drawings, in which: Figure 1 is a schematic perspective view of a hypersonic aircraft containing four ramjet engines placed side by side in accordance with a preferred embodiment of the present invention ; Figure 2 is a schematic side sectional view of the aircraft shown in Figure 1; Figure 3 is a schematic enlarged sectional view

  part of one of the super-combustion ramjet

  sonic, taken along line 3-3 of Figure 1; FIGS. 4 to 7 are views in partial section and

  in elevation of the hood of a super-combustion ramjet

  sonic, which show the heat dissipating CVD diamond layer and internal cooling structures; Figure 8 is a side elevational view of a chemical vapor deposition reaction chamber showing a set of filaments to be used

  to create the heat dissipating CVD diamond layer

  their in order to apply it to the leading edge of the hood of the ramjet with supersonic combustion; and FIG. 9 is a sectional view, seen from above, of

  ap D device shown in Figure 8.

  FIG. 1 shows a schematic representation of a hypersonic aircraft 10 comprising four ramjet engines supersonic combustion 12 a-12 d, placed side by side, according to a preferred embodiment of the present invention.

  ramjet 12 a-12 d with supersonic combustion are effective

  spaces to propel the aircraft 10 at hypersonic speeds of up to about Mach 18 Each ramjet 12 a-12 d with supersonic combustion is defined in part by the cover 14 spaced radially inwards from the median surface

  16 of the aircraft body 10 Side walls 18 a-18 e, are

  paced from each other, extend between the surface

  diane 16 and the cover 14 to define ramjet 12 a-

  12 d with supersonic combustion, generally rectain-

  gular All ramjet 12 a-12 e are essential-

  ment identical and the following description will not refer

  that only one of these motors, namely the motor 12 a, the

  very being essentially identical to this one.

  If we refer to Figures 1 and 2 r each statoreac-

  supersonic combustion engine also includes a surface

  this planar front 20 aui extends obliquely upstream of the

  median surface 16 from the groove 22 (Figure 2) of the re-

  minimum flow region defined between the median surface 16 and the cover 14 In the embodiment shown, the ramjets 12 a-12 d are ramjets integrated into the airplane which partly use the surfaces of the airplane 11

  to define ramjet with supersonic combustion.

  These plane surfaces include the middle surface 16 of the body and the front surface 20 of the body. The surfaces also include the flat surface 24 of the nose which extends upstream from the front surface 20 of the body at a point d inflection 26 and at an obtuse angle relative to the front surface 20 The surface 24 of the nose extends at the edge

  of attack 28 of the aircraft 10 The surfaces of the aircraft yes de-

  end the ramjets 12 a-12 d further include the curved rear surface 30 of the body extending downstream from the median surface 16 of the body at the rear end 32 thereof As seen more particularly on the Figures 2 and 3, the cover 14 is radially inward space of the middle surface 16 thus aue of certain parts of the front surface 20 and the rear surface 30 in order to define a converging entry 34 starting from the leading edge

  36 from the cover 14 to the throat 22 a combustion chamber

  divergent tion 38 starting downstream of the groove 22, which one

  can also call entrance 22 from the combustion chamber

  tion, to the rear end 32 of the median surface of the body and a divergent outlet nozzle 40 leaving downstream of the combustion chamber 38 at the rear end 32 and defined in part by the rear end 42 of the cover 14 aui extends rearward from the plane of the rear end 32 of the surface of the body to the trailing edge 44 of the cover 14 The ramjet 12 a further comprises means 46 for supplying fuel to the chamber

  combustion 38 at the upstream end 48 thereof

This.

  The fuel supply means 46 comprises one or more

  traditional fuel injectors 50 spaced transversely from each other at the end

  upstream 48 of the combustion chamber Traditional conduits 52

  fuel units bring together: by allowing the flow to pass, a traditional fuel tank 54

  including a traditional fuel pump,

  jets 50 The fuel delivery means 46 is efficient

  this for sending fuel 56 through the injectors 50 into the combustion chamber 38 In a preferred embodiment, the fuel 56 is liquid hydrogen also

  goes from liquid to gaseous state when injected

  tion in the combustion chamber 38 by the injectors 50.

  The entry 34 into the ramjet is further limited in part by both the front surface 20 of the aircraft body and the surface 24 of the nose to provide external compression of the ambient air flow 58 of a well

  known More specifically, entry 34, which includes the over-

  front face 20 and the nose surface 24 is dimensioned and configured so as to generate a shock wave 60 at the level of the nose: oblique which leaves from the leading edge 28 of the aircraft towards the rear descending to the edge 36 of the hood, and a shock wave 62 obliques at the front which goes downstream from the point of inflection 26 to the leading edge 36 of the hood The two shock waves, nose and front, 60 and 62 provide external pressure, also called recompression, of the flow 58 of the ambient air in order to increase the static pressure of

  this one with a corresponding increase in its temperature-

  ture stati Ueo The flaking 58 of ambient air thus comp-ime results in a flow 64 of supersonic compressed air which is channeled in the inlet 34 generally parallel to the

  front surface 20 The air flow 64 strikes in an ob-

at

  halter on the cover 14 and generates a shock wave 66 of

  pot, oblique, which Dart from leading edge 36 of cover to

  the back at an acute angle.

  According to a preferred example of embodiment of the present invention, a method for operating the ramjet 12 a in order to propel the aircraft 10 includes the

  Mistletoe steps involve sending the 64 super air flow

  compressed sonic input 34 to the combustion chamber

  38 at a static temperature and a static pressure

  As described above: the recompression of the flow 58 of the ambient air due to shock waves from the nose and the front, 60 and 62, compresses in a suipersoniclue way

  the air flow 58 to a predefined static pressure

  finished, with a predetermined static temperature cor-

  respondanteo In the embodiment of the invention shown in FIGS. 1 to 3, the inlet 34 includes a Dersoniaue diffuser which further increases the pressure

  static and correspondingly increases the temperature

  static ture of the ambient air flow 50 by con-

  internal traction to provide a flow of air 64

  award winning supersonic to the combustion chamber 38 The fact of

  provide a compressed air flow (-ipersonic to the heat-

  combustion of a supersonic combustion ramjet

  qaue at a predetermined static pressure and temperature

  born is classic The entrance, front and nose of a hypersonic aircraft are dimensioned in a traditional way and

  configured to generate static pressure and temperature

  predetermined static ture of the air flow in order to

  give a relatively large increase in pressure

  static pressure from the leading edge 28 of the aircraft to

  to the combustion chamber 38 and, consequently, a temperature

  high static scratch to obtain spontaneous ignition of the

  air / fuel mixture in the combustion chamber.

  It will therefore be understood that the leading edge 36 of the cover 14 will be subjected to various difficult conditions including particulate matter carried by the air which proves Guent

  wear out erosion and abrasion and to stresses of-

  extremely high localized heating Mist requires not only special materials but also special heat removal processes Not only the leading edge 36 is subjected to a high localized heating but the differences in tem Temperatures between the leading edge

  36 and the adjacent regions of the cover 14 cause

  additional high thermal traces on the leading edge 360 A layer of CVD diamond has the advantageous effect of dissipating the significant localized heating at the level of the

  leading edge Gue 36 towards adjacent regions which are much

  blow colder This dissipation characteristic of

  the heat of the CVD diamond layer decreases the heating

  ment located at the leading edge 36 and decreases in

  in addition to the thermal stresses placed on the leading edge

as described above.

  The heat dissipation properties and the ca-

  extremely important pacities to withstand thermal shocks

  mics of CVD dialan-t layers will be usable for

  the majority of the concepts of edge cooling

  taaue All cooling concepts have a character-

  common ristics the definition of a flow path o The geometric configuration of a classic engine hood is

  a bevel from 10 to 130 with a leading edge before a diameter

  from 2.54 mm to 6 c 35 mm (0: 1 to 0 to 25 inch) The waves of

  oblique shock formed by the rebon compression surfaces

  say upstream in the engine by realizing on the

  internal walls of the motor There is an interaction between

  be the reflected shock wave and the local limiting layer

  the flow path so that the nominal heat flow on the side wall is locally amplified due to the shock wave / boundary layer interaction Similarly, as hypersonic motors generally involve rectangular cross sections, the effects recirculation in the corners can also locally amplify the nominal heat fluxes on the side walls o A layer of CV Di diamond will therefore be useful for dissipating heat in these regions, thus minimizing the formation of localized hot spots o An overlay or outer layer serving to em Prevent oxidation of the diamond layer CV Dr can be applied if necessary, desirable or suitable o The overlay must be relatively thin so as not to damage the heat dissipation function of the CVD layer The overlay must also have a coefficient of thermal expansion little different from the CV Di diamond in order to the expensive

  thermal constraints between these materials

  Oxidation protectors include for example the

  silicon (which will form stable oxides of silicon)

  silicon carbide and vitreous silicon coatings

  res As already mentioned, these coatings must have just the thickness sufficient to ensure their protective function against oxidation thickness which results in

  general by about 10 microns minimum and up to more

  hundreds of microns These overlays also help provide additional abrasion resistance

  which is already provided by the CVD diamond coating.

  With regard to the CVD diamond layer which provides the thermal flow path on the leading edge of the cover, or on other internal cooling schemes, reference is made to FIGS. 4 to 6 The edge d attack 80 is

  the basic metal structure aui can be a reductive alloy

  tungsten or molybdenum fraction due to its re-

  mechanical resistance, its ability to withstand the temperatu-

  re and its low thermal conductivity Copper alloys are also suitable materials for this construction The layer 82 of CVD diamond is fixed to the edge

  by a solder line 84 Optionally: a coating

  outer surface 86 in silicon, silicon carbide

  il ciumi or another thin coating can be applied to the diamond screen layer 82 to protect it from the effects

  oxidants in the ambient air flow In addition, a tu-

  yau 88 of evaciuat-ioni tvypiauement porous or mesh sintered metal can optionally be mounted on the inner surface of the leading edge 80 The layer 88 provides the conduit to bring the metal liauide of the well of

  heat from the condenser to the heat source of the evaporator

  during the hollow interior cavity 89 in the cover contains a cooling fluid In the preferred case

  of a supersonic air combustion ramjet

  plate constitutes the evaporator and the condenser not shown

  smelled, is coupled to the hydrogen fuel by the

  heat sink The interior cooling of the edge of the

  plate 80 is made in this way.

  Dar impact cooling can be achieved as shown in FIG. 5 by adding a single injector 90 which

  can send coolant to the surface

  dull leading edge 80 This coolant is normally the vehicle's fuel which cannot be

  1 methane hydrogen or another hydrocarbon medium.

  In addition to cavity 89 in the dot ca can send the fluid

  cooling to an aqui recovery collector

  reads impact fluid to cool side walls

of the hood.

  8 if we refer to FIG. 6, we see that the impact cooling has been retained but that a layer 92 of CVD diamond is fixed to the inner surface of the leading edge Dar the solder line 94 High conductivity

  CVD diamond coating on the inside will help

  reduce thermal gradients associated with cooling

  intense localization at the internal surface We com-

  take other forms of internal cooling

  can be used for the turbojet engine component

  both the CVD diamond layer and are included in the scope of the present invention In FIG. 7, a self-supporting diamond layer 82,

  possibly covered with a layer 86 on its surface ex-

  is fixed to the leading edge 80 In having the layer 82, because of its structure, becomes the leading edge. If we now refer to the CVD diamond layer

  attached to the component of the jet engine for the purpose of

  heat sipation, the low pressure growth of the dia-

  miant was baptized chemical vapor deposition "or" CVD "in this area o Two predominant techniques 7 nantes of

  CVDs are preferred in the literature o L Tune of these tech-

  nics involves the use of a dilute mixture of hy-

  drocarbon (conventionally methane) and hydrogen in which the hydrocarbon content generally varies from approximately 01% to 2.5% of the total volumetric flow The gas is introduced via an auartz tube located just above a hot tungsten filament yes is electrically heated Le to a temperature between approximately 1750 and 2400 C. The

  gas mixture dissociates at the surface of the fila-

  the diamond condenses on a heated substrate placed just below the hot tungsten filament The substrate is held in a cup heated by a resistor

  (usually molybdenum) and is heated to a temperature

  stripping between about 500 and 11000 C the substrate

  can also be heated by the filament.

  The second technique involves the application of a

  plasma charge in the previous process with filament La

  plasma discharge serves to increase the nucleation density

  tion, the speed of growth: and is supposed to favor the formation of diamond layers rather than diamond particles isolated from each other Among the plasma installations which have been used in this field, there are

  three basic installations One of them is an installation

  microwave plasma, the second is an installation

  tion of radio frequency plasma (inductively coupled

  ve or capacitive) and the third is an installation of

  plasma i direct current Plasma installations at mid

  microwave or radio frequency use related equipment

  tively complex and expensive which usually requires networks of chords to electrically connect electrical energy to the product plasma. Furthermore, the rate of growth

  of the diamond obtained with these two installations is relative-

* ment weako With regard to traditional CVD techniques useful in the present invention, gaseous mixtures of hydrogen / hydrocarbon are sent to a CVD reactor

  at the initial stage The sources of Deuvent hydrocarbon

  Closes the gases of the methane 2 series, namely methane 2 ethane, propane, unsaturated hydrocarbons, such as ethylene, acetylene, cvcloheene and benzene and other similar elementso However, it is the methane is preferred The molar ratio of hydrocarbon to hydrogen is roughly between approximately 1:10 and approximately 1: 1000, the value approximately 1: 100 being referenced This gas mixture can optionally be diluted in an inert gas

  like argon The gas mixture is at least partial-

  thermally broken down Dar one of the different tech-

  One of these techniques known in the art

  plique the use of a hot filament yes is normally formed of tungsten, moly-bdene, tantalum or alloys

  of these US Patent 4,707,384 illustrates this process.

  Partial decomposition of the gas mixture can also

  also be carried out using a current discharge

  continuous or electromagnetic radiation in radiofre-

  ouence in order to create a plasma, as proposed in the bre-

  American vets NO 4,749,587, 4,767,608 and 4,830,702 as well

  that in US patent N 5 4 434 188 which relates to the use

  microwaves D The substrate can be bombarded with

  electrons during the CVD decomposition process

  In addition to US Patent 4,740,263 In addition to these two main methods of making CVD diamond, other pro-

  yielded include flame or combustion, heat, photolysis and hybrid plasma and filament processes yes may be used if necessary, desirable or suitable.

  Whatever the particular process used to generate

  the partially decomposed gas mixture on the substrate

  is maintained at a high temperature.

  mant CVD yes is typically between 500 and 1100 C; preferably between about 850 and 950 ° C, where the growth rate of the diamond is most imortantee in order to minimize the size of the grains.

  between about 1.3 to 130,000 Pa (0.01 to 1,000 Torr), and before

  tagging between 13,300 and 106,000 Pa (100 to 800 Torr) are taught in the technique, reduced Dressi Gons being preferred Additional details on CVD processes

  may be known by referring to the following documents :.

  Angus, et al 'Low Pressure Metastable Growth of Diamond and "Diamoindlile" Phases "' Science, vol 241, pages 913-921 (August 19 1988); and Bachmannr et al, D i Diaiond Thin Films", Chemical and Engineering News, pages 24-39 (May 15,

  1989) The lessons of all these documents are incorporated

res here for reference.

  A commonly preferred apparatus for manufacturing a CVD diamond layer for heat dissipation to be applied to the hypersonic leading edge of a supersonic combustion ramjet is shown in Figures 8 and 9 The reactor 100a structure and

  traditional operation as described above Com-

  me the diamond layer intended to be applied on a jet engine component has a unique and asymmetrical geometry, it is a challenge to form this layer so that it has an acceptable uniformity and that it is free of residual stresses So , the apparatus and the method of forming the diamond layer are niqueso The reactor 100 uses a total of seven filaments 7 namely the filaments 102 a to 102 g The seven filaments are separated by a distance of approximately 1:25 cm (0: 5 Soft) The

  102 g filament is placed at the tip of the edge of the

  taaue 104 of the taundis hood that the filaments 102 a to 102 c are placed on one side and the filaments 102 d to 102 f are placed on the opposite side of this one Separate power adjustment for each group of filamerts is ensured nar three separate electric supply feeds 106 a, 106 b and 106 c The design of the reactor 100 is unicnue by the flexibility of the arrangement of these filaments The length of each of the filaments can be adjusted by simply releasing the screw 108 intended for filaments 102 a to 102 c and sliding

  the clamp 1110 along the support rod 112 The same arrangement

  sition applies to filaments 102 d to 102 f and to filament

  102 g and will therefore not be described specifically here.

  The separation interval between the filaments and the substrate and the angle of the groups of three filaments can also be adjusted The Dorte-filaments 114 is supported by the clamp 110 The positioning of the filaments can be modified if the screw 116 is released and repositioned the support

  114 You can do this with all the fila-

  elements in order to obtain the desired arrangement The filaments are preferably tungsten wires and are maintained

  in place at their lower end by a handle

  chon de quartz 118 For simplicity, only one of the

  filaments of groups of three was shown in the figure

  re 8 Likewise, the lower groups of screws and adjusting clamps have not been described in a specific manner but are arranged in a similar manner. The apparatus shown in FIGS. 8 has been used and

  9 to grow a layer 120 of diamond on a sub-

  trat 104 by stretching a screened sheet forming a screen (10 strands / cm by 100 strands / cm) preferably made in MB (although one can also use W or Ti) on a substrate using bolts (not shown ) Methane and

  hydrogen (118: 2 molar ratio) were then

  seen at a flow rate of 120 sccm under a total pressure of 1,300 Pa (10 Torr) When a stable state is reached for this gas flows, concentrations and

  partial pressures, we started the reactions of forma-

  tion of the diamond by sending a current of 90 amperes (15 amperes per filament) with an applied voltage of 27 volts to obtain the incandescent state of the tuniasterine filaments

  yes had a length of 15.24 cm (6 inches) and a diameter

  be 0.38 mm (0.015 Soft) I 1 note that we

  in this case only used six filamtents The fila-

  were 1.27 cm (0.5 inch) apart and were between 0.85 and 1.0 cm from the surface of the substrate The surface of the substrate was heated to a temperature of about 700 to 10,000 C and the diamond growth conditions maintained for 34 days to produce a diamond layer which had a thickness of less than one millimeter. When the screen mesh of the substrate 120 was unbolted, the desired diamond layer was easily senarated and

  was ready to be soldered or attached to other materials

  denier to a leading edge of a real hood.

  The brazing of the CVD diamond layer cannot be

  crease using different bra alloy compositions

  wise well known in the diamond technique For example 2 one can use the brazing alloys described in the American patents X 3 894 673, 4 018 576, 4 527 998, 4 772

  294 and 4 93 l 363, patents incorporated herein by reference

this.

  It is understood that the description above does not

  has been given to purely illustrative and non-limiting

  and or variations or modifications may be made

  worn as part of the Dresenite invention.

Claims (17)

  1 o Component (14) of a jet engine, characterized by   because it has a surface in contact with a drain   gas and that said surface is covered with a layer (82) of diamond obtained by chemical phase deposition steam (CVD).   2 component according to claim 1, characterized in that said layer of CVD diamond has a thickness comprised between about 10 and 1000 microns.   3 o Component according to claim 1, characterized in that   that said CVD diamond layer is brazed to said surface   this. 4 Component according to claim 1, characterized in that   that said CVD diamond layer is covered with a   oxidation resistant layer (86).   Component according to claim 4, r characterized in   that said overlay is a silicon-based coating.   Component according to reverdicatioa 5, in which said overlayer is chosen from silicon oxide, carbide of silicon and silica glass.   7 component according to claim 1 characterized in that said surface is the leading edge (80) of the cover of a ramjet with combustion supersoniceo 8 component according to claim 1 characterized in that it comprises an interior cavity which contains a fluid cooling.   9 Component according to claim 1, characterized in that it comprises an interior-re surface which also carries a layer of CVD diamond. Component according to claim 8, characterized in that   that it has an interior surface which also carries a diamond CV ,.   11 Component according to claim 1, characterized in that said layer of CVD diamond dissipates heat in order to create a thermilac evacuation path from said covered surface. 12 Method for creating a flow path dissipating heat from the surface of a jet engine component   which is in contact with a flow of hot gas,   laughed at in that it comprises coating said surface with a layer of diamond obtained by chemical deposition in vapor phase (CVD).   13 Method according to claim 12, characterized in that said CVD diamond layer has a thickness comprised between about 10 and 1000 microns.   14 Method according to claim 12, characterized in that   that said CVD diamond layer is brazed to said over-   face. Method according to claim 12, characterized in that   aue said layer of diamond CV Di is covered with an over- oxidation resistant layer.   16 Method according to claim 15, characterized in that   aue said overcoat is a coating based on silicon.   17 The method of claim 16, wherein said overlay is selected from silicon oxide, silicon carbide and silica glass. 18 Method according to claim 12, characterized in that   that said surface is the leading edge of the hood of a stat   supersonic combustion toreactor.   19 Method according to Claim 12, characterized in that it comprises an internal cavity which contains a cooling fluid 20 Method according to Claim 12, characterized in that it comprises an internal surface which also carries a layer of CVD o diamond 21 Method according to claim 19, characterized in that   that it has an inner surface that also wears a CVD diamond che.   22 Method according to claim 12, characterized in that   that said CVD diamond layer is produced in an apparatus   a chemical vapor deposition (CVD) board which comprises: a screened metal sheet forming a screen, fixed to said substrate which is placed in said apparatus, said screened sheet being able to be heated to the CVD diamond forming temperature; a series of metal filaments adjacent to said mesh sheet, said filaments being connected to a source of electric current and held between clamps   which are supported in an adjustable manner by support rods   Harbor; wherein said CVD diamond layer is made under CVD diamond formation conditions in said apparatus, then said CVD diamond layer is removed from said mesh sheet and said CVD diamond layer is   attached to said surface of the jet engine component.   23 Method according to claim 22, characterized in that said CVD diamond layer is brazed to said surface   of the jet engine component.   24 Method according to claim 22, characterized in that   that said CVD diamond layer is mechanically attached   that at said surface of the component of the jet engine o   Method for protecting a reactive engine component   tion having a surface which is in contact with one or   several flows of hot gas or gas loaded with par-   ticles, characterized in that it comprises the coating of said surface with a layer of diamond obtained by deposit chemical vapor phase (CVD).   26 Method according to claim 25, characterized in that said particles comprise one or more elements   among dust, earth, water and ice.   27 A method according to claim 25, characterized in that said CVD diamond layer dissipates heat in order to create a heat evacuation path from said covered surface. 28 Method according to claim 25, characterized in that   that said CVD diamond layer is produced in an apparatus   chemical vapor deposition board (CUD) which includes:   a wire mesh sheet forming a screen,   xed to said substrate which is placed in said apparatus said new mesh sheet to be heated to the CVD diamond forming temperature; a series of metallic filaments adjacent to said mesh sheet, said filaments being connected to a source of electric current and muaintenius between Equi Dinces are supported in an adjustable manner by support rods; in water said CVD diamond layer is produced under CVD diamond formation conditions in said apparatus, then said CVD diamond layer is removed from said mesh sheet and said CVD diamond layer is   attached to said surface of the jet engine component.   29 Method according to claim 28, characterized in that said CVD diamond layer is brazed to said surface   of the jet engine component.   A method according to claim 280 characterized in that said CVD diamond layer is mechanically attached to   said surface of the jet aircraft co-applicant.