Milling tools are influenced by extreme heat and mechanical loads. One of the ways to increase their life expectancy is to put coating over cutting edge. Using coatings on milling tools increases their thermal protection (decrease/ reduce their thermal conductivity) and reduces friction between contact surfaces.
In diploma thesis we performed a research on life expectency of various different milling tools and tool coatings. We compared them with well established milling tolls (OSG). At the begining of diploma thesis we describe theoretical basis of milling tools with an emphasis on ball milling tools, tool coatings and observe life expectancy and tool wear. The second part of the experiment talks about the performance on CNC machine Mori Seiki Frontier. By using testing results made on tempered tool steel 58 HRC we are able to determine tool's life expectancy. Results show us that the best life expectancy was achieved by milling tool KX44 coated with AlTiN coating. The reference milling tool achieved VB11=0,057 mm and VBmax11=0,216 mm in time of eleven passages. In the same number of passages with the tool KX44 achieved VB11=0,144 mm and VBmax11=0,329 mm. The test tool reached 250% bigger tool wear ,VB, and 150% bigger maximum wear, VBmax. The average time of other tools waer was 67,0 min.
In my opinion the biggest factor for the resulting diffrences in tools wear is different tools geometry. Using different coatings also effects on tools wear, but in much smaller effect. Tests show us that with the right selection of tool geometry and coating we increase the milling tool life expectancy.
|
