Wear Mechanisms of Cutting tools in Machining
Sara Saketi is a PhD-student within SIFOS research school. Her project is a cooperation between Högskolan Dalarna, Sandvik Coromant and Uppsala University. Sandvik Coromant is the world’s leading supplier of cutting tools.
In machining, the efficiency of the machining operation and the surface quality of the machined component is strongly dependent on the wear and life-time of the cutting tool. The latter is mainly controlled by the mechanical and tribochemical properties of the work and tool materials and the cutting conditions (cutting speed, cutting feed, etc.). Thus, in order to improve the robustness of a machining operation and minimize the machining costs it is important to predict the tool-life and to improve the wear resistance of the cutting tool. The aim of this project is to investigate wear mechanisms of cemented carbide cutting tools in machining titanium alloys and stainless steel.
In order to strengthen the knowledge of wear of cutting tools, the worn cutting inserts are characterized using high resolution scanning electron microscopy (FEG-SEM, Zeiss Ultra 55). The element composition of the worn surfaces are analyzed using energy dispersive X-ray spectroscopy (EDS, Oxford Inca Energy) and Ulvac-Phi 700 Xi Scanning Auger Nano prope (SAN).
Alicona InfiniteFocus 3D optical surface profilometer is used to compare the 3D surfaces of a worn cutting edge with an unworn reference cutting edges.
The following image shows a SEM image of a cross section of a worn cemented carbide cutting tool used in turning titanium. In this part of project the wear of relevant cutting tool was investigated and it was found that for combinations of low cutting speeds/-feeds crater and flank wear attrition wear mechanism dominates while for combinations of medium to high cutting speeds/-feeds a diffusion wear mechanism was found to dominate the wear. It is also concluded that combinations of high cutting speed/-feed may result in catastrophic failure due to severe plastic deformation and macro cracking.
“Influence of Tool Surface Topography on the Material Transfer Tendency and Tool Wear in the Turning of 316L Stainless Steel” and “wear behaviour of two different cemented carbide grades in Turning 316 L Stainless Steel” are the title of researches is done so far as the part of Sara s project.