Tool wear under dynamic cutting conditions

Official URL: http://risc01.sabanciuniv.edu/record=b1124804 (Table of Contents)

Machining processes are very common in manufacturing technology. These operations are applied in manufacturing of almost every mechanical part. Because of their frequent use, these processes have to be efficient and economical. On the way to lower manufacturing costs, there are many parameters that engineers need to consider. Tool wear is one of the most important considerations in machining operations as it affects surface quality and integrity, productivity, cost etc. The most commonly used model for tool life analysis is the one proposed by F.W. Taylor about a century ago. Although the extended form of this equation includes the effects of the important cutting conditions on tool wear, tool life studies have always been performed under stable cutting conditions, and the effects of chatter vibrations have never been considered. This study presents an initial attempt to understand the tool life under vibratory cutting conditions. The wear data have been collected in turning and milling operations of mild steel and titanium alloy under many different cutting and chatter conditions. The results indicate significant reduction in tool life due to chatter as expected. Chatter results in serious reduction in tool life about 50% for most of the cases and more than 80% in some higher cutting speeds in turning. The same reduction in tool life due to chatter is about 30% in milling tests. These results can be useful in evaluating the real cost of chatter including the reduced tool life. They can also be useful in justifying the cost of chatter suppression and more rigid machining systems.