Faculty Profiles - TADA Naoya

K-0414 Analysis of Orientation of Polycrystalline Copper during Plastic Deformation

KONDOU Ryouji, ABE Takeji, TADA Naoya, SHIMIZU Ichiro

The proceedings of the JSME annual meeting 1 107 - 108 2001

Language：Japanese Publisher：The Japan Society of Mechanical Engineers

Nonuniform deformation of each grain occurs in the plastic deformation of polycrystalline materials. Accordingly, it is necessary to clarity the behavior of deformation of each grain. The characteristics of each grain that constitutes polycrystalline material varies depending on grain orientation. So it is necessary to pay attention to the difference of grain orientation and the effective measurment technique which throw light on complicated grain deformation. In this paper, automatic measurement using electron backscatter difraction techinque in the scanning electronic maicroscope is performed, and the attention is paid on the grain orientation during plastic deformation to analyze relationship between orientation and plastic deformation.

DOI： 10.1299/jsmemecjo.I.01.1.0_107

604 連続転位分布を用いた粒界クリープ・キャビティの先端近傍応力場に関する数値解析

多田直哉, 大谷隆一, 生田裕也

学術講演会講演論文集 50 149 - 150 2001

K-0530 High Temperature Fatigue Strength of Ni-based Single-Crystalline Superalloy, CMSX-2

OHTANI Ryuichi, TADA Naoya, WADA Atsuhide

The proceedings of the JSME annual meeting 1 185 - 186 2001

Language：Japanese Publisher：The Japan Society of Mechanical Engineers

A nickel-based single-crystalline superalloy, CMSX-2 was investigated from the standpoint of high temperature fatigue strength. Three kinds of push-pull fatigue tests were conducted at 1000℃: (1) PP-test under a sinusoidal stress waveform of 1 Hz-frequency at stress amplitude of 300MPa, the number of cycles to rupture, N_f=8,234, (2) CC-test under a trapezoidal one with hold time in tension and compression of 600s each at stress amplitude of 250MPa, N_f=93, and (3) PP_<preCC>-test, which is PP-test carried out after removal of surface oxide film and small cracks generating during preceding CC-test for 47 cycles, N_f=4,318. A distinguished microstructural difference between PP and PP_<preCC> is that γ'-phase kept the initial cubic shape in PP but it changed to spherical in PP_<preCC>-Nearly 10%-increase in total strain range and 50%-decrease in fatigue life of PP_<preCC> as compared with pure PP-fatigue is attributable to the collapse of γ'-phase.

DOI： 10.1299/jsmemecjo.I.01.1.0_185

K-0719 Observation of Microscopic Deformation Behavior of Pure Aluminum using Ultra-Micro Hardness Tester

TSUBOI Tomoaki, ABE Takeji, TADA Naoya, SHIMIZU Ichiro

The proceedings of the JSME annual meeting 1 327 - 328 2001

Language：Japanese Publisher：The Japan Society of Mechanical Engineers

It is well-known that the hardness of material is related to its mechanical characteristics. In the present study, the evaluation of the microscopic inhomogeneity of polycrystalline pure aluminum is performed by measuring the hardness of respective grains with the recently developed ultra-micro hardness tester. The relationship between the increase in the hardness caused by the work-hardening of the metal and the deformation of respective grains are studied.

DOI： 10.1299/jsmemecjo.I.01.1.0_327

K-0415 Observation of Microscopic Surface Change of Polycrystalline Metal During Plastic Deformation

SONG Hualin, ABE Takeji, SHIMIZU Ichiro, TADA Naoya

The proceedings of the JSME annual meeting 1 109 - 110 2001

Language：Japanese Publisher：The Japan Society of Mechanical Engineers

The surface roughening is closely related to the inhomogeneity of polycrystalline metals, that is, to the inhomogeneous plastic deformation of respective grains. In the present study, inhomogeneous deformation on the free surface of polycrystalline aluminum during uniaxial tension is studied. The inhomogeneous deformation of grains, which is represented by the area of the grain and the grain boundary length in the free surface, is observed by means of the laser-scanning microscope as a nondestructive method. Discussions are made mainly on the evaluation of inhomogeneous deformation of respective grains in polycrystalline aggregate.

DOI： 10.1299/jsmemecjo.I.01.1.0_109