The use of acousto-ultrasonics to determine the quality of the brazing of carbide-tipped cutting tools

Abstract

The goal of this research was to improve the reliability of brazed cutting tools and saw blades through the development of non-destructive evaluation techniques (NDEs) to ensure tool quality. The objective was to determine the sensitivity of an acousto-ultrasonic-based technique to varying braze conditions of carbide teeth. This preliminary research developed a quick NDE technique to test not only the quality of brazed joints during manufacture, but also to inspect the carbide for micro-cracks that may have been introduced by stresses during the brazing process. The test system used an electric spark against the sawblade teeth or plate to initiate a stress wave in the sawblade which was received by an acoustic emission sensor coupled to the sawblade with a fluid couplant. A reading was taken through the saw tip and adjacent to the saw tip on the saw shoulder. An energy reading of each of the signals was obtained. A ratio was then taken of the two energy values. This gave a “self-calibrating” feature taking into account various slots and holes in the blade which could affect the waveform. This system was able to detect braze joints that had too much or too little heat applied during the brazing process, as well as no flux or twisted teeth. Future work will be conducted on saws of various sizes and designs as well as different grades of carbide tips.

Keywords:

• Sawblade
• brazing
• non-destructive testing

Disclosure statement

No potential conflict of interest was reported by the authors.