Evaluation of pore Characterization in Powder Metallurgical Products Using Ultrasonic Scattering

Research Project

Project/Area Number	61460200
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	金属加工(含鋳造)
Research Institution	TOHOKU UNIVERSITY
Principal Investigator	OBTA Mitsuo (1987) Tohoku University, 工学部, 教授 (10005548) 島田平八東北大学, 工学部, 教授 (90005174)
Co-Investigator(Kenkyū-buntansha)	MIHARA Tsuyoshi Research Associate, Faculty of Engineering, Tohoku University (KAWAZOE,Yosh), 工学部, 助手 (20174112) SHIMDA Heihachi %president, Akita National College of Techmology, 校長 (90005174) 小幡充男東北大学, 工学部, 助教授 (10005548)
Project Period (FY)	1986 – 1987
Project Status	Completed (Fiscal Year 1987)
Budget Amount *help	¥5,900,000 (Direct Cost: ¥5,900,000) Fiscal Year 1987: ¥700,000 (Direct Cost: ¥700,000) Fiscal Year 1986: ¥5,200,000 (Direct Cost: ¥5,200,000)
Keywords	Ultrasonics / Non-destructive-evaluation / Ultrasonic Velocity / Ultrasonic Attenuatio / Sintered Compact / Porosity / 気孔寸法 / 粉未加工 / 超音波散乱法 / 気孔形状 / 気孔分布
Research Abstract	The purpose of this investigation is to develop an non-destructive method for evaluating pore structures of porosity and/or pore size of induatrial sintered compacts by using ultrasonics. For this purpose, the suthors tried to introduce an ultrasonic spectroscopy of ultrasonic attenuation and velocity measurement. Six Cu-sintered compacts with different pore size were prepared for this study. These were made of gass-atomized copper powder of 400 <micrn> m in diameter. The structure of these compacts was simple, dual phase with pore and matrix (Cu), and was the most suitable sample for the first step to establish the method of ultrasonic pore structural charaterization for industrial sintered compacts. In order to evaluate the pore structures in paticular from the ultrasonic attenuation spectrum, the attenuation spactrum must be estimated quantitatively. In this study, "Spectrum Shifting Method" was investigated as the quantitative estimation method of attenuation spectrum. As the results, the mean pore diameter could be evaluated from the ultrasonic attenuation by using "Spectrum Shifting Method", and the poeosity could be estimated from ultrasonic velocity mesurement.