Process for producing a rotary anode and the anode produced by such process
The present invention is directed to an improved process for manufacturing a rotary anode for an x-ray tube, said rotary anode comprising a molybdenum support member on which a target layer consisting essentially of tungsten or a tungsten-rhenium alloy is provided by plasma spraying, the improvement comprising: a) preheating the support member to a temperature of from 1150° C. to 1600° C., b) placing the support member in a gaseous atmosphere containing hydrogen and having a pressure of from 0.5 to 0.9 bars and wherein hydrogen is present in a molar ratio of hydrogen to tungsten dioxide of from 5:1 to 50:1, and c) plasma spraying the target layer onto the support layer in said gaseous atmosphere. The invention is also directed to the anode produced by the process.
1 . In a process for manufacturing a rotary anode for an x-ray tube, said rotary anode comprising a molybdenum support member on which a target layer consisting essentially of tungsten or a tungsten-rhenium alloy is provided by plasma spraying, the improvement comprising:
a) preheating the support member to a temperature of from 1150° C. to 1600° C.,
b) placing the support member in a gaseous atmosphere containing hydrogen and having a pressure of from 0.5 to 0.9 bars and wherein hydrogen is present in a molar ratio of hydrogen to tungsten dioxide of from 5:1 to 50:1, and
c) plasma spraying the target layer onto the support layer in said gaseous atmosphere.
2 . The process of claim 1 , wherein the support member is preheated to a temperature of from 1300° C. to 1500° C.
3 . The process of claim 1 , wherein said pressure is from 0.7 to 0.9 bars.
4 . The process of claim 1 , wherein said ratio is from 10:1 to 30:1.
5 . The rotary anode produced according to the process of claim 1 .