| 摘要 |
PROBLEM TO BE SOLVED: To facilitate the removal of Si protrusions by carrying out Si impregnation in a specified gaseous atmosphere when a thermocouple protecting tube is obtd. by molding a prescribed tube using a starting material contg. SIC powder and an org. binder, firing the tube, impregnating molten Si and removing exuded Si. SOLUTION: A tube with one end open and the other end closed is molded using a starting material, contg. SiC powder and an org. binder, this molded body is fired, molten Si is impregnated into the resultant sintered body and Si exuded on the inside and outside of the tube is mechanically removed to produce the objective thermocouple protecting tube. In this method, the Si impregnation is carried out in an atmosphere of pressurized gaseous N2 preferably under 1.2-10atm or in an atmosphere of a gaseous mixture of gaseous N2 with one or more kinds of O-contg. gases selected from among O2 , CO2 , NO2 , CO and NO. |
