Method of coating ceramics and quartz crucibles with material electrically transformed into a vapor phase

Claim 1

A method of coating a quartz crucible for use in the melting of silicon which comprises the steps of: juxtaposing a pair of electrodes, composed of at least one component of a material adapted to coat said crucible, with an interior surface of said crucible; evacuating the space in which said electrodes are juxtaposed with said surface to a pressure of at most 10 -5 torr and maintaining the pressure in said space substantially no higher than 10 -5 torr during deposition; and striking an electrical arc between said electrodes at one end of each of said electrodes at a voltage of substantially 30 to 60 volts and with a current of substantially 50 to 90 amperes by intermittently bringing said electrodes into contact with one another and separating them, thereby depositing material evaporated from said electrodes substantially uniformly over said interior surface of said crucible.

Claim 2

A method of coating a quartz crucible for use in the melting of silicon which comprises the steps of: juxtaposing a pair of electrodes, composed of at least one component of a material adapted to coat said crucible, with an interior surface of said crucible; evacuating the space in which said electrodes are juxtaposed with said surface to a pressure of at most 10 -5 torr and maintaining the pressure in said space substantially no higher than 10 -5 torr during deposition; and striking an electrical arc between said electrodes at one end of each of said electrodes at a voltage of substantially 30 to 60 volts and with a current of substantially 50 to 90 amperes by intermittently bringing said electrodes into contact with one another and separating them, thereby depositing material evaporated from said electrodes substantially uniformly over said interior surface of said crucible.

Claim 6

A method of coating a ceramic with a metal, comprising the steps of: receiving a surface of a ceramic substrate by subjecting it to blasting with particles; preheating said substrate to a temperature of at least 200° C. but less than the melting point of a metal to be applied thereto; juxtaposing said surface of said substrarte with an electrode composed of said metal; evacuating the space in which said electrode is juxtaposed with said substrate to at most 10 -5 torr and maintaining the pressure in said space substantially no higher than 10 -5 torr; and striking an arc with said electrode by intermittently attacking same with another electrode while applying a voltage of substantially 30 to 60 volts across said electrode and passing a current of substantially 50 to 90 amperes through said electrodes to evaporate the electrode composed of said metal and deposit said metal on said surface.

Claim 7

A method of coating a ceramic with a metal, comprising the steps of: receiving a surface of a ceramic substrate by subjecting it to blasting with particles; preheating said substrate to a temperature of at least 200° C. but less than the melting point of a metal to be applied thereto; juxtaposing said surface of said substrarte with an electrode composed of said metal; evacuating the space in which said electrode is juxtaposed with said substrate to at most 10 -5 torr and maintaining the pressure in said space substantially no higher than 10 -5 torr; and striking an arc with said electrode by intermittently attacking same with another electrode while applying a voltage of substantially 30 to 60 volts across said electrode and passing a current of substantially 50 to 90 amperes through said electrodes to evaporate the electrode composed of said metal and deposit said metal on said surface.