Process for applying nitride layers to titanium
AssigneeDegussa AG
InventorFriedrich Preisser
Life of this patent
Estimating the term…
Abstract
An economical process for applying nitride layers to titanium and titanium alloys. Within a short time, layer thicknesses of 20 .mu.m are obtained by pressure-nitriding in an ammonia atmosphere. To this end, temperatures of 500.degree. to 1000.degree. C. and pressures of 0.2 to 9 MPa are used.
Claims25
A process for applying a nitride layer to a part made of titanium, a titanium alloy or a mixture thereof, comprising:
- contacting said part in a thermochemical treatment with ammonia or ammonia-containing gas mixture in a chamber furnace at a temperature of 500.degree. to 1000.degree. C. and under a pressure of 0.2 to 9 MPa, wherein the ammonia partial pressure is at least 0.2 MPa.
A process for forming a nitride layer on a part made of titanium, a titanium alloy or a mixture thereof, comprising:
- loading the part into a chamber furnace;
- evacuating the chamber furnace to a subatmospheric pressure in a first evacuation step;
- inputting ammonia gas or an ammonia containing gas mixture into the chamber furnace to thereby increase a pressure in the furnace to the range of 0.2 to 9 MPa;
- contacting the part in a thermochemical treatment with the ammonia or ammonia-containing gas mixture at a temperature in the range of 500.degree. to 1000.degree. C., wherein the ammonia partial pressure is at least 0.2 MPa, for a sufficient period of time to provide the nitride layer on at least a portion of the part;
- evacuating the furnace chamber to a subatmospheric pressure to remove hydrogen liberated during the treatment in a second evacuation step;
- and
- recovering the part having the nitride layer formed thereon.
A processes for forming a nitride layer on a part made of titanium, a titanium alloy or a mixture thereof, comprising:
- loading the part into a chamber furnace;
- inputting ammonia gas or an ammonia containing gas mixture into the chamber furnace to thereby increase a pressure in the furnace to the range of 0.2 to 9 MPa;
- contacting the part in a thermochemical treatment with the ammonia or ammonia-containing gas mixture at a temperature in the range of 500.degree. to 1000.degree. C., wherein the ammonia partial pressure is at least 0.2 MPa, for a sufficient period of time to provide the nitride layer on at least a portion of the part;
- and
- evacuating the furnace chamber to a subatmospheric pressure to remove hydrogen liberated during the treatment.
Dependencies are inferred from the claim text.