The Effect of Coatings on Cutting Force in Turning of C45 Steel

This article focuses on the development of a mathematical model of a cutting force that is applicable for coated and uncoated cutting tool inserts and aims to enable more accurate calculation of the cutting force. Two common PVD coatings, AlTiN and TiAlCrN, were used. Firstly, a mathematical model of the cutting force based on the specific cutting force and cutting area is proposed. This mathematical model considers the cutting speed and coating correction factor as well as the real cutting edge geometry, i.e., it includes both the straight and rounded parts of the cutting edge. For this proposed model, material constants for C45 steel, which was machined with uncoated inserts, were obtained. Before determining an equation for a coating correction factor and implementing it into the model, experimental cutting force data for coated and uncoated inserts were compared using a paired t-test. The result was that the difference between them was statistically significant. Their percentage difference was found to be up to 4%. The correction factor equation that was obtained and implemented into the mathematical model was applied to compare the calculated and experimental data of the coated inserts, also using a paired t-test. The result was that the difference between them was insignificant. Moreover, their percentage difference was found to be up to 0.6%.

Effect of Process Modes on Tangential Component of Cutting Force during Belt Rotary Grinding of Aluminium Alloy Blanks D 16

These days, in the manufacture of units and mechanisms of ships, aircraft and other technological machines, industrial robots, long-sized products from D 16 (Standart GOST-R) aluminum alloy are used, for the processing of which a complex for belt rotary grinding has been developed. The outcome measures of the rotary belt grinding process depend on the cutting forces generated during the processing process. According to cutting forces, process stability is diagnosed, values of surface roughness indices, temperatures and cutting modes are calculated according to displacement balance equation. The article is devoted to obtaining a mathematical model establishing the relationship between the tangential component of the cutting force and cutting modes during belt rotary grinding of D 16 aluminum alloy.

Prediction of Cutting Force and Chip Formation from the True Stress–Strain Relation Using an Explicit FEM for Polymer Machining

In the present work, an explicit finite element (FE) model was developed for predicting cutting forces and chip morphologies of polymers from the true stress–strain curve. A dual fracture process was used to simulate the cutting chip formation, incorporating both the shear damage failure criterion and the yield failure criterion, and considering the strain rate effect based on the Johnson–Cook formulation. The frictional behaviour between the cutting tool and specimen was defined by Coulomb’s law. Further, the estimated cutting forces and chip thicknesses at different nominal cutting depths were utilized to determine the fracture toughness of the polymer, using an existing mechanics method. It was found that the fracture toughness, cutting forces, and chip morphologies predicted by the FE model were consistent with the experimental results, which proved that the present FE model could effectively reflect the cutting process. In addition, a parametrical analysis was performed to investigate the effects of cutting depth, rake angle, and friction coefficient on the cutting force and chip formation, which found that, among these parameters, the friction coefficient had the greatest effect on cutting force.

Impact of Cutting Parameters on Cutting Force of AISI 410 and AISI 420 MSS during CNC Dry Milling

A CNC dry milling experiment was conducted for the machining parameter optimization of two grades of Martensitic Stainless steel (MSS). Optimization is done by employing Taguchi method (S/N ratio and ANOVA). The specimens used are MSS grades 410 and 420.The experiments were designed by employing L9 orthogonal array for 3 levels of feed and spindle speeds. The impact of these parameters on cutting force was analyzed. The analysis reveals that spindle speed constitute the maximum impact on cutting force for both MSS grades. Optimum cutting parameters are obtained at 30 mm/min (feed rate) and 1500 rpm (spindle speed). Due to higher Chromium and Carbon content in AISI 420 MSS resulted higher cutting force values compared with AISI 410 MSS. Optimum values of cutting parameters are estimated for improving productivity and quality. The predicted values at optimal conditions are estimated. The results indicate a good conformity with the outcome of experiment.