Tomáš Vopát

Reduction of Milling Time by Using CAQ Technologies

Abstract The paper is focused on reducing machining time by using 3D optical scanner of ATOS Triplescan II. Workpiece was a forging die, which was renovated by hard facing. The contribution deals with comparing the CAM simulation of roughing process according to the STL model imported from ATOS, and simulation without thus-defined workpiece. The results indicate a significant improvement of machining time based on CAQ technology and usage of the ATOS device for measuring the errors of weld deposit.

Influence of Finish Milling Strategies on the Tool Wear

Abstract The article deals with the tool life of ball nose end mills during finish milling of weld deposit. The aim was to determine and compare the wear of ball nose end mill for different types of ball end milling strategies, as well as to specify particular steps of the measurement process. For tool life test, DMG DMU 85 monoBLOCK 5-axis CNC milling machine was used. In the experiment, the cutting speeds, feed rates, axial and radial depth of cut were constant. The coated cemented carbide was used as tool material. The cutting tool wear was measured on Zoller Genius 3s and laser Blum Micro Compact NT. The results show different achieved tool life of ball nose end mills depending on the finish milling strategy.

Deformation and FEM Analysis of the Chip Root in Face Milling Process

This paper was focused on analysis of deformation process in the chip root after milling of material C45. The aim of research was to evaluate the degree of deformation by using the method of oriented test lines. Experimental value of degree of deformation was compared to achieve in computer simulation of milling process in Deform software. The results from the chip root indicates of little differences between simulations and experimental obtained value of degree of deformation.

Effect of Substrate Bias and Coating Thickness on the Properties of nc-AlCrN/a-Si x N y Hard Coating and Determination of Cutting Parameters

Nitride hard coatings Al25.5Cr21Si3.5N were deposited on WC-Co substrates with a different thickness and a negative substrate bias voltage by the LAteral Rotating Cathodes Arc technology. The nanoindentation tests were performed for analysis of AlCrSiN coatings in order to determine the most promising combination of parameters for subsequent machining. On the basis of results of nanohardness measurement and Ratio H/E*, which represents the resistance to plastic deformation and cracking, deposition conditions were selected for coating of turning cemented carbide inserts. For the evaluation of coating adhesion to substrate, Mercedes adhesion test was used. Chip forming tests and long-term tool life tests were performed for determination of cutting parameters (cutting speed, feed rate and depth of cut) for AlCrSiN coated cemented carbide inserts when machining austenitic stainless steel material.

Influence of Ultrasound on Delamination during Machining of GFRP Composite Material

In many present applications is requested decreasing of weight of components and increasing of their strength. Often unique properties are required. These properties could be solved by using of composite materials. However, different material properties of matrix and reinforcing material cause issues during machining, such as rapid tool wear and delamination of composite. Therefore there is afford to enhance machining process by different ways to decrease tool wear as well as delamination of composite. This article deals with comparison of conventional milling and ultrasonic assisted milling of glass fibre reinforced polymer (GFRP) composite material by special designed cutting tool.

Influence of Ultrasonic Assistance on Delamination During Machining of Different Composite Materials

A lot of nowadays researches are focused on increasing strength of the components and decreasing their weight, or obtaining unique properties. Composite materials are one of the results of the researches. However, different material properties of matrix and reinforcing material usually cause certain difficulties during conventional machining, such as rapid tool wear and delamination of composite. Therefore, focusing on machinability of this kind of materials is necessary. Scientists have discovered several ways of how to satisfactorily machine different composite materials. Seco Tools Company starts developing a new design of the cutting tools. Researchers of the Stanford University have devised a diamond-like carbon (DLC) coating available to effectively cut matrix as well as reinforce fibres. DMG Mori Company has implemented ultrasonic assistance into machining process and reached enhanced machinability. This article compares conventional milling and ultrasonic assisted milling of the composite materials – glass fibre reinforced plastic (GFRP) and two types of carbon fibre reinforced plastics (CFRP) by using a special designed cutting tool. The results could be applied to determine when ultrasonic assistance is advantageous and what advantages it brings about. The purpose of this study is to determine ways to increase efficiency and productivity of machining different types of composite materials.

Influence of Ultrasonic Assistance on Delamination During Machining of CFRP Composite

Many nowadays researches are focused on decreasing the weight of components and increasing their strength, or obtaining unique properties. One of the results of the researches are composite materials. However, different material properties of matrix and reinforcing material cause certain problems during conventional machining, such as rapid tool wear and delamination of composite. Therefore, other researches start focusing on machinability of this kind of materials. Scientists have discovered several ways of how to satisfactorily machine composite materials. Seco Tools Company starts developing a new design of the tools. Researchers of the Stanford University have devised a diamond-like carbon (DLC) coating available to effectively cut matrix as well as reinforce fibers. DMG Mori Company has implemented ultrasonic assistance into machining process and reached enhanced machinability. This article compares conventional milling and ultrasonic assisted milling of the carbon fiber reinforced polymer (CFRP) composite material by a special designed cutting tool. The results could be applied to determine when ultrasonic assistance is advantageous and what advantages it brings about.

The Influence of Copy Strategy on the Tool Life of Ball End Mills and Achieved Surface Roughness

The article deals with the tool life of ball nose end mills and surface roughness of steel C45 depending on up-copying and down-copying. The cemented carbide and high speed steel was used as tool material. Furthermore, the new and sharpened cutting tools were also compared. In the experiment, the cutting speed, feed rate, axial and radial depth of cut were not changed. The results show different achieved surface roughness of machined material C45 and tool life of ball nose end mills depending on the copy milling strategy for various tool materials.