Coating processes – Electrical product produced – Integrated circuit – printed circuit – or circuit board
Patent
1985-10-30
1987-06-23
Pianalto, Bernard D.
Coating processes
Electrical product produced
Integrated circuit, printed circuit, or circuit board
219 7616, 219121PY, 219121PL, 427 38, 427316, 4273741, 4273983, 427422, B05D 306
Patent
active
046752056
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a process for the treatment of the surface of a part, e.g. made from a heat sensitive material, such as a composite material, more particularly usable as a preliminary stage for the activation of a surface of a part coated with a material such as a ceramic material.
More specifically, it relates to carrying out a surface treatment of a part to be coated, in order to increase the adhesion of the coated material then sprayed on to the part and it is more particularly applicable to producing parts made from a composite material coated with a refractory material.
Over the last few years new composite materials have been developed and particularly those constituted by plastic substances reinforced by inorganic fibres, such as glass, carbon, silica or graphite fibres. However, the use of these materials has caused certain problems when they are to be provided with an adhesive covering, e.g. made from a ceramic material.
Thus, in the case of composite materials based on a plastic substance reinforced with inorganic fibres, the anchoring points of the covering are particularly constituted by microcracks formed in the resin at the fibres and this does not make it possible to obtain a good adhesion between the composite material and the covering material coating.
SUMMARY OF THE INVENTION
The present invention relates to a process for the surface treatment of a heat sensitive material part, e.g. of a composite material, which makes it possible to modify the surface state of the part, with a view to then forming an adhesive covering thereon.
The inventive process for the surface treatment of a heat sensitive material part comprises subjecting the surface of said part to the action of a plasma of a hot gaseous arc in an inert atmosphere and then cooling the thus treated surface by spraying on to it a cooling liquid, which is at a temperature close to its saturation temperature.
Generally, the gas of the plasma is nitrogen, argon, hydrogen, helium or a mixture thereof, accompanied sometimes by the introduction of traces of reactive gases (water, BCl.sub.3, etc.) in order to accelerate the formation of active sites.
For carrying out the surface treatment, it is possible to use a plasma gun of a conventional type, e.g. comprising an anode essentially shaped like a hollow cylinder, a cathode arranged substantially concentrically to the anode and means for supplying a gas or gaseous mixture to the space between the anode and the cathode, in order to produce a plasma jet there.
By subjecting the surface of the part to a hot gaseous plasma, the latter is heated under the effect of infrared radiation and it is also cleaned by bombarding with high-energy ions, which makes it possible to tear away or remove on the one hand the gaseous atoms firmly absorbed on the surface of the part, whilst on the other hand producing active sites with a view to the attachment of the covering. Moreover, the ultraviolet radiation of the gaseous plasma makes it possible to bring about a final crosslinking of the material forming the part, when the latter is a plastics material. When the part is made from a composite material and has a matrix of a plastics material reinforced by inorganic fibres, it is assumed that there is an activation of the carbon atoms of the plastics material matrix flush with the surface of the part.
For carrying out the surface treatment by means of a gaseous plasma, the part is generally placed in a tight enclosure scavenged by an inert gas, such as argon and then a gaseous plasma is directed on to the part using a plasma gun. The supply intensity of the plasma arc is generally 400 to 800 A and the gas constituted e.g. by a mixture of argon and nitrogen is introduced into the gun under a pressure of 0.1 to 0.2 MPa. In general, the gun is moved along the surface of the part, in order to treat the totality thereof and several treatment cycles can be carried out, if necessary.
Simultaneously, the treated surface undergoes strong cooling, which can be carried out
Boncoeur Marcel
Hansz Bernard
Commissariat a l''Energie Atomique
Pianalto Bernard D.
LandOfFree
Surface treatment of a part and use of this treatment for improv does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Surface treatment of a part and use of this treatment for improv, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Surface treatment of a part and use of this treatment for improv will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-720429