Abstract

Evaluation of hardness by interrogating the residual indentation in a static test using a microscope can be hampered by poor image quality. Image digitization with processing may overcome this but is limited by cost, convenience, and speed. It is shown that the indented surface on the sample in a Brinell test acts effectively as a spherical mirror. Thus, placement of an optical ring light coaxial with the microscope objective and at varying distances from the sample surface produces a distinct right light image that can be correspondingly altered in diameter. The Brinell hardness can be computed by determining the ring light to sample distance after adjusting the ring light image diameter to equal the indentation diameter. This approach is verified experimentally and found to be accurate, cost effective, and expeditious.

© 2007 Optical Society of America

Hard-molded 51 cm long waveguide array with a 150 GHz bandwidth for board-level optical interconnects

Xiaolong Wang, Li Wang, Wei Jiang, and Ray T. Chen
Opt. Lett. 32(6) 677-679 (2007)

Optimization of optical ring resonator devices for sensing applications

M. Sumetsky
Opt. Lett. 32(17) 2577-2579 (2007)

Subsurface damage and microstructure development in precision microground hard ceramics using magnetorheological finishing spots

Shai N. Shafrir, John C. Lambropoulos, and Stephen D. Jacobs
Appl. Opt. 46(22) 5500-5515 (2007)

Optical phase distribution evaluation by using an S-transform

Serhat Özder, Özlem Kocahan, Emre Coşkun, and Hilal Göktaş
Opt. Lett. 32(6) 591-593 (2007)

Wave-optical simulation of hard-x-ray nanofocusing by precisely figured elliptical mirrors

Cameron M. Kewish, Lahsen Assoufid, Albert T. Macrander, and Jun Qian
Appl. Opt. 46(11) 2010-2021 (2007)