The Effect of Tool Edge Geometry on Tool Performance and Surface Integrity in Turning Ti-6Al-4V Alloys

Abstract

This paper focuses on the influence of cutting tool edge geometry, cutting speed and feed rate on the tool performance and workpiece’s surface integrity in dry turning of Ti-6Al-4V alloy using PCBN inserts. The parameters evaluated are tool life, wear rate, wear mechanisms, surface roughness and subsurface microstructure alterations. The rate of wear growth of the insert was assessed by progressive flank wear using optical microscope by taking photographs after certain length of cut. The wear mechanism at the end of tool life was investigated in detail using scanning electron microscope (SEM) and EDAX analysis. The results show, by increasing the cutting speed and feed rate resulted in tool life reduction. Cutting with honed edge insert at cutting speed of 180 m/min has shown very little wear, even after 20 min of cutting. The honed insert proved less sensitive to increases in feed rate than the chamfered insert. In general the honed insert showed a significant improvement in tool life. All inserts failed due to attrition wear and adhesion. No flank notch wear was observed, but some crater wear occurred at the chamfer land. Microstructure alteration was not found when machining using the different edge geometry. In these trials, the subsurface micro structural deformations in the direction of cutting were deformed grain boundaries and elongation of grains. Chip smearing and debris on the surface was also found.

Investigation of the influence of the forming process and finishing processes on the properties of the surface and subsurface of hybrid components

“…It is generally assumed that an increase in cutting speed leads to a finer surface quality. However, investigations show that the effects are strongly materialdependent and can show opposite tendencies [27,28]. The material-specific differences can be attributed to the material separation mechanisms and side effects, such as adhesions at the cutting edge [29].…”

Influence of selected parameters of drag finishing on tool microgeometry

“…The magnitude of the influence of the cutting edge radius decreases with increasing hardness of the material being processed. It is possible to say that a smaller radius of rounding of the cutting edge means less roughness of the surface [17][18][19]. The residual stresses also behave on the same principle.…”

Production-Related Surface and Subsurface Properties and Fatigue Life of Hybrid Roller Bearing Components

“…The surface roughness is significantly influenced by the feed rate during turning. In addition, cutting speed and tool microgeometry also determine the final roughness of a component [30,31]. The mechanical and thermal effects during chip formation are the main factors influencing the subsurface condition.…”

“…This generally leads to compressive residual stresses below the surface. On the other hand, large cutting-edge radii lead to greater temperature development, which promotes the formation of tensile residual stresses [30,31]. The influence of process parameters and tool microgeometry on the surface and subsurface properties of hybrid components and their influence on the operating behavior is currently inadequately investigated.…”