Investigation of influence of tool rake angle in single point diamond turning of silicon

Abstract

This paper presents an investigation of the effect of tool rake angle in single point diamond turning (SPDT) of silicon using experimental and simulation methods. Machining trials under the same cutting conditions were carried out using three different rake angle tools. In order to delve further into the rake angle effect on the output parameters including material removal, stresses and crack formation, at the onset of chip formation and steady-state conditions, a simulation study using smoothed particle hydrodynamics (SPH) approach was performed. The simulation results were incorporated and found in good agreement with experimental observations. The results indicate that diamond tool wear rate and surface generation mechanism significantly vary using different rake angle tools. The continuance of compressive and shear deformation sequence at the chip incipient stage governs the high-pressure phase transformation (HPPT) as a function of rake angle and tool wear. The capability of diamond tool to maintain this sequence and required hydrostatic pressure under worn conditions is highly influenced by a change in rake angle. The proportional relationship of cutting force magnitude and tool wear also differs owing to disparate wear pattern which influence distribution of stresses and uniform hydrostatic pressure under the tool cutting edge. This subsequently influences structural phase transformation and therefore frictional resistance to cutting. Mainly frictional groove wear was found dominant for all diamond tools in machining of silicon.

Influencing Factors and Theoretical Models for the Surface Topography in Diamond Turning Process: A Review

“…The optimized range of the tool overhang, i.e., 12 mm to 16 mm, is recommended through the experimental observations [118,119]. Mir et al studied the influence of rake angle in diamond turning of silicon with molecular dynamics method, and reported that a positive rake angle diamond tool contributes to the generation of cracks on the machined surface and therefore affects the final surface topography [120]. Meanwhile, the selection of cutting fluids affects the lubrication condition [121], tool wear rate [122] and temperature distribution [123,124] on the contact interface between the diamond tool and workpiece surface, which further has impact on the final surface topography.…”

Indirect cutting tool wear classification using deep learning and chip colour analysis

“…Despite recently some online tool inspection systems for machining becoming available in the scientific literature [3], most of the industrial direct methods possess this strong limitation. The indirect methods, such as those based on the cutting force/torque or spindle current analysis, are more efficient and therefore very widespread in the industry [4][5][6][7][8]. Their accuracy, which is high only in very repetitive scenarios, and the system costs are their limiting factors.…”

A Simulated Investigation of Ductile Response of GaAs in Single-Point Diamond Turning and Experimental Validation

“…In this regard, single-point diamond turning (SPDT) [23][24][25][26][27][28] becomes a good candidate due to its capability of mass production of 2D and 3D nanostructures with high form accuracy in a single pass. Through establishing machining parameters to meet brittle-to-ductile transition condition, some researchers [29][30][31] have already successfully obtained nano-smooth machined surfaces on GaAs although it is regarded as a difficult-to-machine brittle material, attributing to its low elastic modulus and fracture toughness.…”