Solid Carbide End Mill Research Articles

Influence of Cutting Parameters on Machinable Glass Ceramic Processed by End Milling

This experimental research work attempted to use End milling on Machinable Glass Ceramic (MGC) using micro grain solid carbide end mill under dry conditions. The predictive Surface Roughness model has been developed in terms of Spindle speed, Feed rate and axial depth of cut by Response Surface Methodology (RSM). The influence of each milling parameter analyzed and results showed that axial depth of cut was the most dominant variable. The adequacy of the model has been verified by ANOVA.

Evaluation of Arc Evaporated Coatings on Rounded Surfaces and Sharp Edges

This paper presents measurements and cutting tests related to coating features on sharp cutting edges and rounded objects. One typical feature of plasma based deposition processes is the formation of a sheath region around the object to be coated. The formation of the sheath has some implications on the coating of three dimensional objects, since rounded surfaces and edges are subjected to different ion flux density as compared to a flat surface. Solid carbide drills of different diameters were coated with a TiAlCrSiN coating by cathodic arc evaporation. It is noted the deposition rate increases with decreasing drill diameter, and the fraction of elements with high expected mean ionization charge state is higher for a small as compared to a large diameter drill. The observations are explained by Coulomb attraction of ions from the plasma in combination with the sheath to tool radius ratio in combination with resputtering and scattering in the gas/plasma phase. Solid carbide end mills were coated with TiAlN at three different substrate biases; -10, - 40, and - 80 V. It is observed that the coating stresses increase drastically with increasing bias, and the corners of the tools have different stress levels than the flatter areas. In addition, the fraction of Ti in the coating around the corners is increased significantly when the bias increases. The end mills were tested in a machining test, and the best performer was the variant deposited at - 40 V.

Optimization of Surface Roughness Based on Multi-Linear Regression Model and Genetic Algorithm

During the high-speed milling operations of 7050-T7451 aluminum alloy using solid carbide end mills, helical angle, axial and radial depth-of-cut have significant effects on the milling uniformity. A surface roughness predictive model of work-piece was developed by using a full-factorial experimental design and multi-linear regression technology. Genetic algorithm was utilized to optimize the helical angle and cutting parameters by means of a series of operations of selection, crossover and mutation based on genetics. The result shows that it is possible to select optimum axial depth-of-cut, radial depth-of-cut and helical angle for obtaining minimum cutting force and reasonably good metal removal rate.

Tool-Life Optimization in High-Speed Milling of Aeronautical Aluminum Alloy 7050-T7451

A new approach is presented to optimize the tool life of solid carbide end mill in high-speed milling of 7050-T7451 aeronautical aluminum alloy. In view of this, the multi-linear regression model for tool life has been developed in terms of cutting speed and feed per tooth by means of central composite design of experiment and least-square techniques. Variance analyses were applied to check the adequacy of the predictive model and the significances of the independent parameters. Response contours of tool life and metal removal rates were generated by using response surface methodology (RSM). The analysis results show that it is possible to select an optimum combination of cutting speed and feed per tooth that improves metal removal rate without any sacrifice in tool life.

Selection of an optimal parametric combination for achieving a better surface finish in dry milling using genetic algorithms

In machining, coolants improve machinability, increase productivity by reducing tool wear and extend tool life. However, due to ecological and human health problems, manufacturing industries are now being forced to implement strategies to reduce the amount of cutting fluids used in their production lines. A trend that has emerged to solve these problems is machining without fluid – a method called dry machining – which has been made possible due to technological innovations. This paper presents an experimental investigation of the influence of tool geometry (radial rake angle and nose radius) and cutting conditions (cutting speed and feed rate) on machining performance in dry milling with four fluted solid TiAlN-coated carbide end mill cutters based on Taguchi’s experimental design method. The mathematical model, in terms of machining parameters, was developed for surface roughness prediction using response surface methodology. The optimization is then carried out with genetic algorithms using the surface roughness model developed and validated in this work. This methodology helps to determine the best possible tool geometry and cutting conditions for dry milling.

Analysis of factors affecting the high-speed side milling of hardened die steels

This paper presents a study of the surface roughness obtained in high-speed side milling of hardened die steels. The influence of cutting speed, feed per tooth, axial depth and radial depth of cut is studied using a 2 4−1 fractional factorial design of experiments. The workpiece material was the die steel Böhler K340, hardened at 61–62 HRC. This material may be considered a substitute for traditional die steel materials. It has the advantage of having better performance than traditional die steels. A solid carbide end mill coated with (Al, Ti, Si)N was used as cutting tool. Many variables have been controlled before and during the machining process in order to obtain reliable experiments. Finally, it has been determined the factors and interactions that are statistically more significant for modelling the surface roughness, R a.

Wear of PVD-coated solid carbide end mills in dry high-speed cutting

The aim of the present research of wear behaviour on the PVD-coated solid carbide end mills in dry high-speed cutting (HSC) is to find the main causes for unpredicted tool life. The contribution presents some results of characteristic wear types. The high cutting temperature, which is a result of high-speed cutting enhance diffusion and oxidation process. Diffusion processes between the chip and the top rake surface of the cutting edge result in crater wear, and oxidation reactions with the environment (air cooling in dry cutting) induce scaling of the cutting edge. The characteristic wear of such tools (so-called “central wear”) can be used to define the tool life in the case of high-speed milling of alloyed tool steel X63CrMoV5.1 (hardness >47 HRC).

Surface integrity of hot work tool steel after high speed milling-experimental data and empirical models

High speed milling (HSM) using small diameter solid or indexable insert tungsten carbide end mills, with coatings such as TiAlN is now an established technology for manufacturing moulds and dies in a range of hardened tool steels. The paper presents experimental results and corresponding empirical models for workpiece surface integrity (SI) of hardened AISI H13 hot work tool steel, when HSM using solid carbide ball nose end mills coated with TiAlN. The influence of cutting speed, feed rate and workpiece angle on SI (workpiece surface roughness, microstructure, microhardness and residual stress) was studied using a full factorial experimental design with two levels of each factor. Where appropriate, empirical models were proposed in order to predict SI based on cutting parameter inputs. No significant changes in microstructure and microhardness below the machined surface were found. Within the range of cutting parameters tested, the operating parameters that gave the lowest workpiece surface roughness did not result in the most compressive residual stress distribution below the machined surface. A compromise in parameter selection is therefore necessary to achieve desired roughness and integrity.