Missile components made of fiber-reinforced ceramics

Details Missile components made of fiber-reinforced ceramics Missile components made of fiber-reinforced ceramics

1999-12-10

2002-10-08

Barefoot, Galen L. (Department: 3644)

Aeronautics and astronautics

Aircraft structure

Details

C244S172200, C244S11700R, C102S374000

Reexamination Certificate

active

06460807

ABSTRACT:

This invention is directed to missiles comprising a nose, fixed fins or movable fins, gas rudders, propelling nozzles and blast pipe inserts
5
, combustion chamber liners
6
, tail cone, grid fins, fluid elements and radomes or subcomponents thereof, said components being made of ceramic material.
Exposed locations such as edges, corners and tips of missiles that move at very high speeds in the near-earth atmosphere, are subject to surface temperatures of more than 1700° C. due to aerodynamic heating. Very high temperatures in excess of 2500° C. occur at components of missile engines the solid propellants of which sometimes burn at temperatures in excess of 3500° C. It is desirable for the components involved to possess sufficient structural strength and functionality even at such temperatures in order to successfully complete the overall task of the missile. Until recently, the structural strength of most of the metallic components that are subject to high-temperature use was realized by employing high-temperature resistant metals and metal alloys, cooling and thermal insulation. Such measures are expensive and in all cases require additional weight so that the given task can be accomplished. In the case of mobile gear, especially missiles, any additional weight is disadvantageous so that weight-reducing solutions should be sought after.
In a known embodiment of a missile, the nose, fixed fins or movable fins, gas rudders, propelling nozzles and blast pipe inserts, combustion chamber liners, tail cone, grid fins, fluid elements and the radome are made of different metals and metal alloys. These missile components are the ones that are exposed to thermal and mechanical maximum loads.
Having regard to the current design of such missile components it is necessary due to the above-mentioned high temperatures, high mechanical loads and high pressures to use high temperature-resistant metals or metal alloys (for instance tungsten, molybdenum, Inconel) that exhibit high mechanical strength and temperature resistance. As these temperature-resistant metals and alloys will soften already at about 800° C. with concurrent losses in strength, additional active cooling is required. Another severe drawback of the metallic components of the missile is their great weight which leads to restrictions in respect of missile acceleration and speed.
It is the object of the present invention to provide noses, fixed fins or movable fins, gas rudders, propelling nozzles and blast pipe inserts, combustion chamber liners, tail cones, grid fins, fluid elements and radomes or subcomponents thereof all made of ceramic material for use with missiles and having high resistance to temperature, pressure and abrasion, erosion resistance, low density or light weight, respectively, high thermal conductivity, low heat expansion, while permitting an almost unlimited variety of geometries and shapes.
As a solution to the specified object the nose, fixed or movable fins, gas rudder, propelling nozzles or blast pipe inserts, combustion chamber liners, tail cone, grid fins, fluid elements and the radome or subcomponents thereof of the kind specified above are characterized in accordance with this invention in that the nose
1
, the fixed fins
2
or movable fins
3
, the gas rudder
4
, the propelling nozzles and blast pipe inserts
5
, the combustion chamber liners
6
, the tail cone
71
the grid fins
8
, the fluid elements
9
and the radome
10
, or subcomponents thereof, are made of carbon fiber-reinforced silicon carbide (C/SiC) and/or carbon fiber-reinforced carbon (C/C) and/or silicon carbide fiber-reinforced silicon carbide (SiC/SiC).
Hence the nose
1
, the fixed fins
2
or movable fins
3
, the gas rudder
4
, the propelling nozzles or blast pipe inserts
5
, the combustion chamber liners
6
, the tail cone
7
, the grid fins
8
, the fluid elements
9
and the radome
10
, or subcomponents thereof are made of fiber-reinforced ceramic material or of combinations of various fiber-reinforced ceramic materials and after infiltration will form a monolithic structure. As an overall effect, the temperature stability of these missile components is increased with a concurrent reduction in weight.
It has been found that C/SiC and/or C/C and/or SiC/SiC possess excellent strength up to high temperatures so as to permit employment even under severe conditions. In addition, besides low density there result high wear resistance, resistance to oxidation and, besides the excellent temperature stability, also high temperature cycle resistance.
The material is particularly gas and liquid-tight when the surface is provided with a protective coating.
The great variety of geometries and shapes in conjunction with low weight as well as the excellent temperature stability and the high or controlled thermal conductivity, which permit correspondingly reduced cooling capacities, should be particularly stressed. With certain missiles it is possible due to the high temperature stability of C/SiC and C/C and SiC/SiC to provide no cooling or thermal insulation at all.
There is a distinction between C/SiC and C/C and SiC/SiC with continuous fiber-reinforcement and chopped fiber-reinforced C/SiC and C/C and SiC/SiC. The former material of C/SiC or C/C or SiC/SiC, which may be laminated, compressed or wound is characterized by particularly high strength and especially low density. A surface coating may be provided in order to increase the resistance to oxidation. To this end it is preferred to apply protective coats of silicon carbide and/or silicon dioxide and/or molybdenum disilicide on the component surfaces. The latter is superfluous in the case of chopped fiber-reinforced C/SiC because this material is particularly resistant to oxidation and corrosion. Also, it exhibits extremely good thermal conductivity and features particularly high resistance to thermal shocks. It is mainly suited for mechanical treatment in its green state. In this connection, noses
1
, fixed fins
2
or movable fins
3
, gas rudders
4
, propelling nozzles or blast pipe inserts
5
, combustion chamber liners
6
, cone tail
7
, grid fins
8
, fluid elements
9
and radomes
10
or subcomponents thereof can readily be shaped with random geometries either in a single piece or from various separate segments of C/SiC preforms and/or C/C preforms by mechanical treatment.
Advantageously, the individual segments of nose
1
, fixed fins
2
or movable fins
3
, gas rudders
4
, propelling nozzles and blast pipe inserts
5
, combustion chamber liners
6
, tail cone
7
, grid fins
8
, fluid elements
9
and radomes
10
or subcomponents thereof are co-infiltrated or co-siliconized so as to provide the desired monolithic structure. This design is especially suited for C/SiC or C/C or SiC/SiC with chopped fiber-reinforcement, in which case the individual segments are mechanically treated prior to being co-siliconized or infiltrated, respectively. Such a missile component
1
-
10
can readily be joined by means of fasteners such as screws or bolts or flanges, preferably made of C/SiC and/or C/C and/or SiC/SiC. Also, cooling ducts and/or recesses having round, rectangular or slot-like cross-sections may be incorporated in the missile components
1
-
10
by mechanical treatment in the green state.
The method according to this invention moreover provides for hybrid-type or segment-type design of the missile components
1
-
10
. Hybrid-type monolithic missile components are formed by mechanical treatment of blanks and sub-segments, which are preferably made of C/SiC and/or C/C and/or SiC/SiC or of appropriate combinations with continuous fiber-reinforcement and/or chopped fiber-reinforcement, and by the subsequent infiltration of these individual segments with silicon and/or silicon carbide and/or carbon.
As a further development of the invention, the inner walls of the missiles or of those missile portions that are subject to high thermal loads are lined in a suitable way with C/SiC or C/C or SiC/SiC segments and provided with cooling via cooling ducts and/or with an insul

Affiliated with

Also associated with

Rating

Missile components made of fiber-reinforced ceramics does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Missile components made of fiber-reinforced ceramics, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Missile components made of fiber-reinforced ceramics will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2996888