SBIR-STTR Award

Due to the inherent properties of Natural Diamond, indenters produced by traditional manufacturing methods yield unacceptable variations in their geometric profiles. It will become our objective to repeatedly reproduce Rockwell indenters with tighter geometric tolerances than those currently available for standardization and traceability. Our primary focus will be the implementation of advanced grinding systems, coupled with experimental techniques and variations in grinding wheel specifications. The variables will translate directly into documented test results directed towards minimal variations in cone angle and radius measurements. Additional areas of evaluation will monitor surface finish, and interpret measurement results gathered both on site and though working relationships with Government Facilities and Universities. COMMERCIAL APPLICATIONS: Diamond indenters produced utilizing advancements in manufacturing technologies would represent an available source of calibration grade indenters with direct traceability to NIST and ISO standards. These indenters would be available to testing laboratories, Test Block manufacturers, Hardness Testing Machine manufacturers, and facilities dependent upon accurate and repeatable hardness testing results, with direct traceability to National Standards

There is a universal need with the Rockwell hardness testing community for NIST Standard Reference Materials (SRM) grade Rockwell diamond indenters. There is primarily one significant difference between these diamond indenters and the standard working grade indenter. SRM grade indenters have tighter tolerances on the geometric parameters than the working grade. Now with the increased precision available in measurement equipment today, those tighter tolerances become measurable. That is essentially the problem and the opportunity. The days of holding the profile up on a 200X optical comparator to visually check whether the radius follows the curve are over. Characterizing the microform on the tip of a Rockwell diamond indenter requires specialized measurement systems. Creating the microform to comply with the stringent tolerances for SRM grade indenters requires equally new manufacturing techniques. In continuation of our Phase I work we propose to develop new manufacturing techniques capable of generating the tighter Rockwell microform on a substantially more consistent basis. We intend to further our investigation into advanced grinding systems. We will also continue pursuit of consistency by varying the wheel grit size, RPM, and spindle speed while maintaining the "one spindle" approach for grind, policy and radius.Commercial Applications: The potential commercial applications of the research results are very promising. NIST is seriously interested in securing a consistent source for Rockwell diamond indenters, which meet the stringent geometrical and performance requirements necessary for the National Standard. NIST needs to be able to provide Standard Reference Materials (SRM) diamond indenters to industry. There is a substantial global market as well. The NIST parameters adhere to ISO specifications and to most (if not all) of the standardizing agencies worldwide. These organizations also desire indenters compliant with the specifications. Beyond the standardizing agencies, industry all over the world is in need of these tools. In an economically global marketplace where all the requirements are becoming universal, the aim of business is to be ISO, NIST, NAMAS, etc. compliant. The traceability provided by these indenters brings everyone a step closer to this goal.