Formation Of Homogeneous Lamellar Structure With Nano-scale Grains Under Material Surfaces By Fine Particle Bombarding

Author:  Yoji Miyachi, Noboru Egami and Hirohisa Kimach
Source:  Conf Proc: ICSP-10 Tokyo, Japan 2008
Doc ID:  2008073
Year of Publication:  2008
Abstract:  
ABSTRACT In this study, the effects of the fine particle bombarding treatment: FPB on crystal structure in the material, were studied. After the FPB treatment, a lamellar work-hardening domain (a lamellar structure) was observed on the specimen surface with the scanning electron microscope: SEM. The crystal orientations in the domain of the lamellar structures were analyzed by the electron backscattered diffraction method: EBSD method with SEM. From the results of Image quality map: IQ map and inverse pole figure map: IPF map obtained by the EBSD method, the several refined crystal grains of sub-micro meter or less in diameter were observed in the lamellar structure. However, the conventional FPB processing locally forms the lamellar structures. In this study, the specimens were moved at the constant speed during the FPB processing and we succeeded in the formation of continuous lamellar structure on specimen surfaces. The observations and hardness test of the microstructure was conducted. The crystal grains in a lamellar structure were nanocrystallized and the hardness in the lamellar structure raised more than 5 times prior to FPB treatment. KEY WORDS Fine Particle Bombarding, Lamellar structure, Nanocrystallization, EBSD measurement