Internal strain distribution of laser peened Ti-alloy rod studied by high energy synchrotron radiation X-rays

菖蒲 敬久; 秋田 貢一; 城 鮎美; 藤城 智之*; 桐山 幸治*; 熊谷 正芳*; 久森 紀之*

no journal, , 

Ti-6Al-4V has excellent corrosion resistance and specific strength, therefore it is widely used for mechanical components. In this study, laser peening was applied to the Ti-alloy rod to improve fatigue strength of the material and internal distributions of residual strain in the rod were measured non-destructively by synchrotron radiation X-ray diffraction technique. On the surface, strains of axial and radial directions were compressive and tensile, respectively. On the other hand, strain of axial direction was tensile and strain of radial direction was low around zero in central region, respectively. The depth introducing compressive strain of axial direction of two specimens was 1 mm. The axial tensile strain increased with a decrease of the diameter of specimen. This indicates that the probability of the internal cracking may be increased with decreasing the diameter of the fatigue specimen.