To obtain a joined part having nearly the same high temperature strength as that of casting a material being a base material by executing diffusion joining by the use of the casting material or powder metallurgical material having lower hardness and nearly the same high temperature strength as that of the casting material as inserting material between heat resistant casting materials.
A turbine blade is cast by precision casting in two back side and belly side split parts, and a passage for cooling air is provided in an internal part. Diffusion joining is executed by holding inserting material between the joining surfaces of two split turbine blades and by heating while pressing. Ni base heat resistant alloy IN 100 and MarM 247 are used as casting material. With respect to inserting material, forging material INCO 718 having nearly the same high temperature strength and lower hardness as that of IN 100 is used in the case of mutually joining IN 100, while powder metallurgical material RENE 95 having nearly the same high temperature strength and lower hardness as that of MarM 247 is used in the case of mutually joining MarM 247.
TEZUKA TSUNAO
MASAKI AKITATSU
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