| Title |
Analysis of Residual Stress through a Recovery Factor of Remnant Indents Formed on Artificially Stressed Metallic Glass Surfaces |
| Authors |
이윤희(Yun Hee Lee); 유하영(Ha Young Yu); 백운봉(Un Bong Baek); 남승훈(Seung Hoon Nahm) |
| DOI |
https://doi.org/10.3365/KJMM.2010.48.03.203 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
amorphous materials; deformation; residual stress; indentation; image analysis |
| Abstract |
An application of the instrumented indentation technique has been expanded from the measurements of hardness and elastic modulus to the analysis of residual stress. A slope of the indentation loading curve increases (or decreases) according to compressive (or tensile) residual stress. A theoretical equation has been established for quantifying residual stress from the slope change. However, a precise observation of the remnant indents is indispensible because the theoretical approach needs actual contact information. In addition, the conventional hardness test is still used for predicting the residual stress distribution of welded joints. Thus, we observed the three-dimensional morphologies of the remnant indents formed on artificial stress states and analyzed stress effects on morphological recovery of the indents. First, a depth recovery ratio, which has been regarded as a sensitive stress indicator, did not show a clear dependency with the residual stress. Thus an analysis on volumetric recovery was tried in this study and yielded a inverse proportional behavior with the residual stress. In addition, an elastic to plastic volume recovery ratio showed more significant correlation with the residual stress. |