Abstract. The goal of this paper is to determine the optimal cutting edge microgeometry for a carbide end mill used in stainless steel machining. The optimal cutting edge microgeometry will be determined through conducting more tool life tests. Tools with three different cutting edge radiuses and one without edge preparation will be tested in order to determine the influence of the cutting edge microgeometry on the wear and tool life. The edge microgeometry is obtained through wet blasting preparation.

The improvement of the microgeometry became a subject of a great interest in cutting tools optimization. This paper approaches the process of cutting edge preparation of solid carbide reamers. It has been analyzed the evolution of cutting edge wear resistance in the material GGG 40 using the scanning electron microscope (SEM). The work also compared the rounded cutting edge reamers realized using wet abrasive jet machining with standard unprepared cutting edge. To obtain different microgeometries were experienced a number of machining strategies, which resulted in four combinations of roundness and forms for the cutting edge. In order to validate the results, the author studied the wear resistance during the reaming tests, the influence of prepared surface of the cutting edge on metallic coating layer adhesion. The final purpose was to determinate the optimal strategy of cutting edge preparation considering the evolution of wear during the reaming process.

This study presents new machining types of advanced materials. Super alloys, ceramics and fiber reinforced plastics started being used on a large scale in the last period, this making necessary the development of new machines and machining processes. This paper describes different methods of ultrasonic machining and makes a comparison between them. By ultrasonic machining can be understood a process that involves axial vibrations with a high frequency and low amplitude, for improving the machining conditions like chip flute removal, tool wear and temperature reducing. In this paper, are presented three different ultrasonic machining methods. In the first one, the cutting process is made by abrasive slurry inserted between the tool and the workpiece, in the second one is made by a rotating diamond-brazed tool and in the last one is made by a special drill. This paper aims to study the current status in this field in order to make a research program through collaboration between the Technical University of Cluj-Napoca and the tool company Gühring KG by which to develop ultrasonic drilling.

Abstract. Generally the study, evaluation and general understanding of end milling cutters are complicated by the complexity of the cutting process and of the cutting tool. The main performance factor of the end milling cutters is given by the durability of the tool. In practice the sound analysis of the tool engaged in the cutting process is used as a simple predictability mean to forecast the future durability of the tool. An alternative or complementary tool to predict future durability is the investigation of the chip behaviour. Chip behaviour investigations can also give clues concerning the possible improvement of the cutting tools. The current article presents a detailed chip behaviour investigation for 5-fluted end milling cutters with different performances and various geometries when approaching different types of metal cutting operations in 42CrMo4 alloy steel. Current study can be applied in future researches regarding the evaluation and the development of end milling cutters. Furthermore the current approach can be used on other types of cutting tools.

This paper aims to establish the mechanism of quality optimization and geometrical improvements for the micro-geometry of solid carbide drills. The purpose of microgeometrical optimization of the cutting edge tools of drills is to improve tool live, cutting speeds and minimizing cutting forces. The most important geometrical feature when drilling with solid carbide drills is the radius or chamfer of the cutting edge, which can be achieved through brushing under a certain angle. Improving this procedure by adding another step, soft granulated polishing, can positively influence on the cutting parameters and decrease the wear effects.

Abstract. Finite element simulations are intended to predict the effects of the technological parameters on the cutting process. The process simulation may reveal many aspects of the cutting process before testing it in laboratory: thermal transfer, elastic and plastic strains, hardening levels and force levels. Simulation is also used for predicting some process issues that are hard, and even impossibly noticeable. This paper analyzes the influence of the K factor on the cutting of C70 material, from the point of view of chip formation and thermal transfer -elements considered important in the evolution of tool wear on the rake and flank surfaces. The chip formation is also studied and considered as a deciding factor in choosing the right geometry of the tool. The obtained results allow to make observation under the optimal geometry that was tested.

In this paper are presented and analyzed a series of problems that are appearing during the CFRP machining. Due to their properties, the composite materials began to replace traditional materials (ferrous and non-ferrous) in a lot of industries leading out the development of new methods of machining or adaptation of the classic. Unlike traditional material, drilling in CFRP is more difficult due to inhomogeneity of the material, its high hardness but also due to lack of knowledge relating to how these materials behave. This paper investigates different types of tool wears as corner wear, welding, crater wear that are appearing in drilling operation due to the highly abrasive nature of the carbon fibers. Also, here is presented an evaluation that refers to the machined hole quality and describe defects as delamination, pull outs, fibers projections, pyrolysis and shape errors. The main goal of this paper is to verify the current status of technique in CFRP drilling in order to develop and produce a new drill geometry in a cooperation between the Technical University of Cluj-Napoca and the cutting tool company Gühring KG.

Abstract. Because of increasingly stricter safety rules, requirements regarding the quality of the components used in the airline industry have increased. Besides the materials used in aircraft components and areas where they are machined, these components must comply certain standards for quality and tolerances of the machined surfaces.Due to high hardness of carbon fibers, hole machining in carbon fiber reinforced plastics has always been a challenge. Wear that occurs in the cutting tool leads to the appearance of workpiece defects such as delamination, peeling, fiber pulling out, etc. Besides cutting tool geometry, a very important role on tool wear, it is owned by the material from which it is made. This paper will make a quantitative assessment of defects that occur in the process of CFRP (carbon fiber reinforced plastics) drilling and a cutting tool wear evaluation. In order to obtain conclusive results for this study will be used three drill bits with the same geometry but different carbides.The aim of this paper is to find which one of this three carbide used is more feasible for holes machining in composite materials reinforced with carbon fibers.