Papers by Keyword: Turning

Abstract: Turning of cast iron and steel is monitored with the help of three-dimensional force and vibration sensors. It is shown the ratios of force components have the similar trends despite of material characteristics. Moreover, the normalized values of dynamic force components (variation of force signals) are the same in a wide variation of cutting condition. These results are discussed and confirmed by a mechanical model of work-tool interaction during the cutting process.

Abstract: Nickel-based alloys provide high corrosion resistance and high-temperature strength but these alloys possess poor machinability. Hastelloy-X is a nickel based alloy that has been used for high temperature use. There are many studies about finite element modeling of aerospace alloys but studies in literature with Hastelloy-X are limited. In the present work, machining characteristics of Hastelloy-X were investigated and a numerical model was developed for the turning operation of Hastelloy-X. Two input parameters (cutting speed and feed rate) were variated in the operations and the results were evaluated considering process outputs such as cutting forces, cutting temperature, effective stresses and chip morphology. Based on the verification of the numerical model using experimental results, presented material model is appropriate for the turning operation of Hastelloy-X at low and medium cutting speed machining conditions.

Abstract: The modern machinery production preserves the trend for the constructive complication of products remains, the inclination not only to use new construction materials but also the substitutes for metals. On the one hand, such solutions allow reducing the metal consumption of machines and improving the performance characteristics of equipment, which is especially important when working with high pressure, humidity and aggressive substances. On the other hand, there is a technological complication of machinability of the listed structures consisting of a combination of dissimilar structural materials (for example, metal-plastic). In addition, the machinable surfaces may have the break elements formed by the secondary structural elements (for example, grooves, protrusions, hollows, small holes and other elements of different numbers, combinations, shapes, and locations). One of the main metal working tasks is to prepare the reliable documentation required for the process engineer to machine such products of the highest constructive and technological complexity.

Abstract: In this paper some experimental determinations on the temperature during the turning of the pure titanium are done, using different cutting conditions. The results are presented as graphical dependencies and also as a screen capture of the values obtained using an adequate technique for registered the temperature during the turning process. Some pictures of the chips shape was captured and presented in this paper

Abstract: This paper presents the results of some experimental research regarding the roughness surfaces, cutting forces for titanium alloys: TiAl5Fe2,5 in the case of turning process.

Abstract: The objective of this study is to examine the influence of machining parameters on surface finish in turning difficult-to-cut-steel. A new approach in modeling surface roughness which uses design of experiments is described in this paper. The values of surface roughness predicted by different models are then compared. Adaptive-neuro-fuzzy-inference system (ANFIS) was used. The results showed that the proposed system can significantly increase the accuracy of the product profile when compared to the conventional approaches. The results indicate that the design of experiments with central composition plan modeling technique can be effectively used for the prediction of the surface roughness for difficult-to-cut-steel.

Abstract: Paper presents some turning process optimization investigations, concerning modeling of tool wear when turning a difficult-to-cut material like nickel based alloy. The workpiece was an aircraft engine part in the form of disc. The aim of the research was an optimization of the cutting data (feed rate) for the purpose to improve the cutting process (stabilization of the cutting force course along the tool path) and increase the material removal rate (efficiency of the machining). A “force material model”, based on the tool behavior in its different wear phases was established.

Abstract: This paper presents the results of the experiments which aimed to determine the value of the specific cutting force (SCF) during longitudinal turning of sintered alloy Inconel PWA. The analysis of the influence of cutting speed on the value of SCF was carried out. Taguchi L9 (2)3 orthogonal array has been applied for experimental design. S/N ratio and ANOVA analyses were performed to identify significant parameters influencing specific cutting force. The analysis presents the method that reduces the cutting power during turning of sintered nickel alloy.

Abstract: The capability of the explicit numerical methods to simulate accurately the real cutting process is investigated in this research work. Smoothed particle hydrodynamics - SPH, classical Lagrangian finite element method - FEM and Multi-Material Arbitrary Lagrangian Eulerian - ALE methods are chosen for the modeling and simulation of the orthogonal metal cutting process of AISI H13 in LS-DYNA. The cutting tool is modeled as a rigid FEM body that incrementally penetrates into the flexible deformable workpiece. At each numerical model, the dynamic elastoplastic behavior of the workpiece material is investigated by taking into account the Johnson-Cook (J-C) constitutive strength material model. The influence of the J-C parameter values found in literature to the models is explored. The obtained numerical SPH, FEM and ALE results of the estimated cutting and thrust forces, stress, plastic strain and thermal distributions are compared with results found in the literature. This comparison, leads to valuable conclusions for the performance of the three methods, concerning the approximation accuracy, model development complexity and computational time demands. Based on these conclusions the SPH method is chosen to simulate the experimentally performed orthogonal cut of AISI 1045. The obtained SPH numerical results outline its advantages among the other explicit simulation methods.

Abstract: The paper deals with the influence of the properties surface layer of notched components. This material is widely used in the automotive industry. This material is subject to different kinds of processing, and therefore present a different quality of the surface layer. For many manufactured components, we find diverse types of notches, such as slots, recesses and holes. They are the place where is stress concentrated, so called the macroscopic stress concentrator. When we focus more on the surface profile, we find the diversity of technologies in the surface, which creates different sizes and shapes of microscopic notches. In these places, there is a higher risk of the destruction of the components. Many designers prescribe unnecessarily high surface quality. It is important to maintain adequate quality of the surface to achieved high durability.