抄録
We have studied on Functionally Graded Material (FGM) which is composed of Cobalt- composition graded cemented carbide layers and a steel substrate. The graded cemented carbide powders stacked on steel were sinter-bonded by pulse-current resistance heating. We manufactured the desired structure and confirmed the stress relief, high bonding strength, and distribution of functionality of coated layers between the surface with high wear resistance and the inside with high toughness. We applied FGM to a stabilizer blade which is oil drilling tool. It was tested in the Ministry of International Trade and Industry's (MITI) Sanriku-oki well in Japan. The wear resistance of FGM blade was 20 times higher than conventional type of stabilizer in the MITI well. These results suggest that we might expect the new stabilizer to have high performance in deeper wells.
