Purpose The purpose of this paper is to determine the influence of the shape of a cutting edge on high-performance milling high-performance cutting. The main purpose of the test was to determine the possibility of increasing the efficiency of machining AlZn5.5CuMg alloy, which is used mainly for the thin-walled structural aerospace components. Design/methodology/approach In all, eight cutters for machining aluminum alloys with different shape of the cutting edge (1 – continuous, 4 – interrupted, 3 – wavy) were tested. The influence of different shapes of a cutting edge on cutting force components and vibration amplitude was analyzed. Furthermore, the impact of a chip breaker on the form of a chip was determined. Findings The conducted test shows that using discontinuous shapes of a cutting edge has impact on the reduction of the cutting force components and, in most cases, on the increase of vibration amplitude. Moreover, using a chip breaker caused significant chip dispersion. The optimal shape of a cutting edge for cutting AlZn5.5CuMg alloy is fine wavy shape. Practical implications Potential practical application of the research is high-performance milling of AlZn5.5CuMg alloy, for example, production of thin-walled aerospace structural components. Originality/value Different shapes of a cutting edge during high-performance milling of aluminum alloy were tested. The influence of tested geometries on HPC process was determined. The most favourable shape of a cutting edge for high-performance cutting of AlZn5.5CuMg alloy was determined.

The article presents the results of experimental studies in high performance milling of AlZn5.5MgCu aluminum alloy. The tests were performed with the use of end mill cutters with different serrated shapes of the cutting edge. End mills with continuous, interrupted and wavy with varied profile radius were used. The tests were conducted on a DMG's DMU 100 MonoBlock machining center with cutting force components measurement in workpiece system capabilities. The experimental tests were carried out using varied radial depth of cut ae and feed per tooth fz parameters according to applied three-level full design of experiment. The relationships between ae and fz parameters and cutting force components for various cutting edge shapes were determined. A continuous cutting edge was adopted as a reference shape. Based on the results of the tests, cutting force components models for analyzed cutting edge shapes were determined. A comparative analysis between the developed models and relationships was conducted. The study proved that when adopting end mills with serrated cutting edges, lower cutting force components are obtained, in comparison with cutters with continuous cutting edges. The results also showed that for end mills with serrated cutting edges radial depth of cut ae has a negligible influence on the feed force component Ff. The results proved, that end mills with serrated cutting edges should be used in high performance machining, where high values of ae and fz parameters are adopted. Furthermore, machining of thin-walled workpieces can be a potential application of these end mills, as lower values of cutting force components reduce the risk of deformation of milled thin walls.

Servicing aircraft engines sometimes requires manufacturing only a single piece of a given part. Manufacturing a turbine disc using traditional methods is uneconomical. It is necessary to use a different machining method recommended for small lot production. One of the proposed methods is WEDM (wire electrical discharge machining). The article presents the results of the research on finishing WEDM of Inconel 718 turbine disc fir tree slots. The influence of infeed, mean gap voltage, peak current, pulse off-time, and discharge energy on the shape accuracy, surface roughness, microcracks, and the white layer thickness were determined. Mathematical models were developed based on the DoE (Design of Experiment) analysis. The statistical significance of the models was verified with the ANOVA (Analysis of Variance) test. The machining parameters control methods that allow achieving the required shape accuracy, surface roughness, and surface layer condition were presented. The obtained surface roughness was Ra = 0.84 μm, the shape accuracy of the slot in the normal-to-feed direction was Δd = 0.009 μm, the profile shape accuracy was Δr = 0.033 μm, and the thickness of recast (white) layer was approximately 5 μm.

Proces szlifowania stosuje się nie tylko w obróbce wykoń-czeniowej ale również jako obróbkę zgrubną dla materiałów trudnoskrawalnych. Efekt końcowy szlifowania zależy od wielu różnych, trudnych do zmierzenia parametrów procesu. Jednym z nich jest stan zużycia ściernicy. Może on powodować błędy w procesie szlifowania, takie jak przypalenia szlifierskie lub powodować wystąpienie drgań typu chatter. Można temu zapobiec monitorując stan procesu. Większość istniejących obecnie systemów jest skomplikowana w zastosowaniach przemysłowych. Wymaga zwykle montażu czujnika niedaleko strefy obróbki. Celem niniejszej pracy badawczej jest opracowanie systemu diagnostycznego dla procesu szlifowania z posuwem pełzającym (creep feed grinding) z zastosowaniem łatwo mierzalnego parametru procesu. Jako sygnał diagnostyczny wykorzystano dźwięk generowany podczas procesu. W artykule przedstawiono możliwość wykorzystania sygnałów audio rejestrowanych podczas procesu do monitorowania stanu ściernicy. SŁOWA KLUCZOWE: szlifowanie, monitorowanie, CFGThe grinding process is used not only in finishing operations but also as a roughing difficult-to-cut materials. The end grinding effects is dependent on a variety of difficult to measure process parameters. One of them is the condition of the grinding wheel wear. It can cause errors in the grinding process, such as grinding burns or cause the occurrence of chatter vibration type. This can be prevented by monitoring the state of the process. Most of the existing systems is complicated for industrial applications. It usually requires mounting the sensor near the machining area. The purpose of this research is to develop a diagnostic system for the Creep Feed Grinding process (CFG) using easily measurable parameter of the process. The sound produced during the process was used as a diagnostic signal. The article presents the possibility of using audio signals registered during the process to monitor the state of the grinding wheel. KEYWORDS: grinding monitoring, CFG WprowadzenieSzlifowanie jako operacja końcowa decyduje o przydatności przedmiotu obrobionego. Błędy na tym etapie produkcji są z reguły bardzo kosztowne. Wynik końcowy szlifowania zależy od wielu różnych, trudnych do zmierzenia parametrów procesu. Osiągnięcie wymaganej jakości obróbki w okresie trwałości ściernicy skutkuje z reguły nadmierną ostrożnością w doborze parametrów obróbkowych. Z tego to powodu obciąganie ściernicy wykonuje się wcześniej niż wymagał by tego jej stan rzeczywisty. Powoduje to przyśpieszone zużycie ściernicy oraz zmniejsza efektywnośc procesu. Efekt ten jest szczególnie widoczny w szlifowaniu CFG gdzie ze względu na znaczne naddadki obróbkowe osiagające wartości rzędu mm oraz rodzaj stosowanych ściernic zużycie ściernicy jest szczególnie intensywne. Z kolei stan czynnej powierzchni ściernicy ma decydujący wpływ na jakość powierzchni obrabianego przedmiotu. Niestety uzyskaną w procesie szlifowania jakość przedmiotu można określić dopiero po jego zakończeniu. Sytuację pogarsza fakt, że w zależności od warunków pr...

High feed Milling is a new milling method, which allows to apply high feed rates and increase machining efficiency. The method utilizes face cutters with a very small entering angle, of about 10°–20°. Thus, the cut layer cross-section is different than in traditional milling. In order to examine the high feed milling (HFM), experimental tests were conducted, preceded by an analysis of cutting zones when milling with an HF face cutter. The face milling tests of 42CrMo4 steel with the use of an HF cutter characterized by an entering angle, dependent on axial depth of cut ap and insert radius r values, as well as with a conventional face cutter with the entering angle of 45° were performed. The study focused on analyzing the vibration amplitude, cutting force components in the workpiece coordinate system, and surface roughness. The experimental tests proved, that when milling with constant cut layer thickness, the high feed cutter allowed to obtain twice the cutting volume in comparison with the conventional face cutter. However, higher machining efficiency resulted in an increase in cutting force components. Furthermore, the results indicate significantly higher surface roughness and higher vibration amplitudes when milling with the HF cutter.