Specific cutting force, tool wear and chip morphology characteristics during dry drilling of austempered ductile iron (ADI)
21 Aug 2013-The International Journal of Advanced Manufacturing Technology (Springer London)-Vol. 69, Iss: 9, pp 2833-2841
TL;DR: In this paper, the impact of cutting conditions on chip morphology and surface roughness is also investigated, and the experimental results revealed that the combination of low feed rate and higher cutting speed leads to higher mechanical and thermal loads on the tool's cutting edge, resulting in higher specific cutting force values.
Abstract: Dry machining is being recognized as ecological machining due to its less environmental impact and manufacturing cost. However, the choice of dry machining is mainly influenced by the workpiece material properties, machining operation and cutting conditions. The recent emergence of austempered ductile iron (ADI) can be considered a significant economic advantage to the increasing industrial demand for cost- and weight-efficient materials. However, due to its microstructure-induced inherent properties, ADI is considered hard-to-machine material. Thus, the dry drilling of ADI is investigated in this paper. The ADI material used in the present study is produced using an innovative process route for near net shape casting production. Drilling experiments are conducted on a DMU80P Deckel Maho five-axis machining centre using PVD-coated carbide tools under dry cutting environment. The dry drilling of ADI under different cutting conditions is evaluated in terms of specific cutting force and tool wear analysis. The influence of cutting conditions on chip morphology and surface roughness is also investigated. The experimental results revealed that the combination of the low feed rate and higher cutting speed leads to the higher mechanical and thermal loads on the tool's cutting edge, resulting in higher specific cutting force values. This behaviour is further supported by the chip morphology analysis, which revealed the formation of segmented chips at higher cutting speed with segment spacing increase with an increase in feed rate. Depending upon the cutting parameters, different modes of tool failures including crater wear, flank wear, chipping, breakage and built-up edge were observed. Surface roughness analysis revealed the influence of tool wear and chip morphology on the machined surface finish.
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TL;DR: In this paper, the authors explore tool wear characteristics in ultra-precision fly cutting and their relationship to cutting forces, cutting chip morphologies, and machined surface quality in UPFC.
Abstract: Although the occurrence of tool wear can affect cutting forces, cutting chip morphologies, and machined surface quality in ultra-precision fly cutting (UPFC), there has been no research in this area due to the complex cutting mechanism of UPFC. The theoretical and experimental research described in this paper was therefore conducted to explore tool wear characteristics in UPFC and their relationship to cutting forces, cutting chip morphologies, and machined surface quality. Results from the study reveal that tool wear characteristics in UPFC include cutting edge fractures, workpiece material welding, wear land formation, sub-wear land formation, and micro-grooves. The cutting edge fractures lead to the formation of ridges on both the cutting chips and machined surface; the material welding increases the thrust force, crushes cutting chips, and deteriorates the machined surface quality; and the formation of wear land on the cutting edge makes the machined surface burred and fuzzy, and the micro-grooves leave some traces on the machined surface. By analyzing the captured cutting force, it is found that the progress of tool wear in UPFC can increase the cutting force and its power spectral density at the natural frequency of the dynamometer. Findings from the research provide rich insight into the relationships of tool wear characteristics to cutting forces, chip formation, and machined surface quality in intermittent cutting processes.
32 citations
Cites background from "Specific cutting force, tool wear a..."
...Depending upon the cutting parameters, Meena and Mansori (2013) observed different modes of tool failure, including crater wear, flank wear, chipping, breakage, and built-up edge [12]....
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TL;DR: In this article, the impact of minimum quantity lubrication (MQL) on the machining behavior of titanium-related stacks through the comparison with the dry cutting condition was investigated, and the results indicated that the MQL yields a reduction of the drilling torque and minimization of specific cutting energy consumption during the drilling process of CFRP/Ti6Al4V stacks.
Abstract: Ti6Al4V alloys are often employed in conjunction with carbon fiber–reinforced polymers (CFRPs) to create hybrid structures for aerospace applications. The introduction of the fibrous composites brings significant challenges to the titanium alloys with extremely poor machinability. Since the minimum quantity lubrication (MQL) is reported as a technologically feasible method to improve the machinability of individual titanium alloys, the current work aims to investigate the impacts of the MQL on the machining behavior of titanium-related stacks through the comparison with the dry cutting condition. Drilling tests were carried out to evaluate the machinability and hole quality of CFRP/Ti6Al4V stacks using the TiAlN-coated and diamond-coated drills. The obtained results indicate that the MQL yields a reduction of the drilling torque and the minimization of specific cutting energy consumption during the drilling process of CFRP/Ti6Al4V stacks. The machining qualities are also improved by the help of the MQL, and better surface morphologies of CFRP holes and less titanium burr formation are achieved under the MQL condition. Moreover, the MQL drilling produces better geometrical accuracy of cut composite holes, and the diamond-coated drills outperform the TiAlN-coated ones in terms of higher geometrical accuracy of cut stack holes.
30 citations
TL;DR: In this article, the performance of six PVD coatings for the tapping of ADI-900 was investigated and the tools were coated using Cathodic arc deposition and were analyzed in two sets of experiments.
Abstract: Austempered ductile iron (ADI) has a high potential to substitute alloy steels in power-train applications. However, the machinability of ADI is difficult and tool life is shortened by the appearance of severe adhesive and abrasive wear on tool cutting edge. In this regard, the deposition of a suitable coating could reduce these phenomena. Previous works have investigated the behavior of coated tools on turning or drilling of ADI, but a knowledge gap exists regarding the tapping operation. In this study, the performance of six PVD coatings for the tapping of ADI-900 was investigated. The tools were coated using Cathodic Arc deposition and were analyzed in two sets of experiments. In the first set, four commercial coatings commonly used in cast iron machining were compared: a monolithic AlTiN, a nanostructured AlCrSiN, and two configurations of AlTiSiN (a multilayer and a gradient). Before film deposition, the high speed steel (HSS) substrate surface was micro-blasted. Cutting performance was evaluated by a combined analysis of tool wear, cutting torque data, and SEM-investigations of the tap surface. The best results were yielded by the gradient AlTiSiN (AlTiSiN-G) but coating delamination was also noticeable in the rake face. The application of a drag grinding pre-treatment led to an improvement of the coating adhesion and to a reduction of wear and torque values. In the second set of experiments, AlTiSiN-G was compared to a double layer TiAlCN-DLC coating and to AlTiSiN-18. The results confirmed that the use of HSS taps coated with AlTiSiN-G is a feasible solution for tapping of ADI-900.
29 citations
TL;DR: In this article, a multi-physical model was developed by implementing different constitutive laws and damage criteria to construct the anisotropic machinability of the stacked composite, and the interrelated effects of the multi-tool-work frictional behavior on hybrid CFRP/Ti cutting were precisely investigated with respect to the specific cutting energy consumption, machined surface morphology, and affected subsurface damage.
Abstract: In manufacturing sectors, machining hybrid CFRP/Ti is usually an extremely challenging task due to the disparate natures of each stacked constituent involved and their respectively poor machinability. The current research focus of hybrid CFRP/Ti cutting was primarily made via the experimental studies, which exhibited high cost and time consuming. In this paper, a new contribution was provided to study the key frictional responses dominating the bi-material machining via the numerical approach. To this aim, a multi-physical model was developed by implementing different constitutive laws and damage criteria to construct the anisotropic machinability of the stacked composite. The interrelated effects of the multi-tool-work frictional behavior on hybrid CFRP/Ti cutting were precisely investigated with respect to the specific cutting energy consumption, machined surface morphology, and affected subsurface damage. A special focus was made to clarify the cutting sequence’s influences on the hybrid cutting operation. The numerical results highlighted the reasonable CFRP → Ti cutting sequence for hybrid composite machining and the pivotal role of multi-tool-work interaction in affecting the frictional responses induced by cutting.
27 citations
Cites background or result from "Specific cutting force, tool wear a..."
...The specific mechanism could be explained by the well-known phenomenon namely as “chip size effect” [61, 62], which stated that there was a substantial reduction of the specific cutting energy with an increase of the uncut chip size....
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...Such findings also agreed well with some experimental observations in either metal alloy cutting [61, 62] or CFRP composite cutting [48, 63] from the literature....
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TL;DR: A prediction model based on adaptive particle swarm optimization (APSO) algorithm and least squares support vector machine (LS-SVM) algorithm is proposed for the recognition of drill wear, and the mean absolute error of the tool wear recognition model is 0.91%, better than the standard LS-S VM algorithm under the same condition.
Abstract: Tool wear monitoring is deemed as an essential technology of the intelligent manufacturing to guarantee the processing quality and improve the machining efficiency. In this paper, a prediction model based on adaptive particle swarm optimization (APSO) algorithm and least squares support vector machine (LS-SVM) algorithm is proposed for the recognition of drill wear. Cutting force signal and vibration signal are used for tool wear monitoring. And these signals are preprocessed through wavelet threshold de-noising algorithm. Multiple signal feature extraction methods are carried out to process the sample data related to drill wear status. The mean absolute error of the tool wear recognition model is 0.91%, better than the standard LS-SVM algorithm under the same condition.
24 citations
References
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TL;DR: In this paper, a plan of experiments, based on the techniques of Taguchi, was established considering drilling with prefixed cutting parameters in a hand lay-up GFRP material.
356 citations
TL;DR: In this article, the formation of saw-tooth chips is attributed to the operation of thermally softened micro-shear zones, which, it is suggested, are a precursor to adiabatic shear initiation.
Abstract: The formation of saw-tooth chips is one of the primary characteristics in the machining of hardened steels with geometrically defined cutting tools. Catastrophic failure within the primary shear zone during saw-tooth chip formation is usually attributed to either cyclic crack initiation and propagation or to the occurrence of a thermo-plastic instability. The results presented here show that the primary instability resulting in the formation of saw-tooth chips is initiation of adiabatic shear at the tool tip and propagation partway towards the free surface. Depending on the work material hardness and cutting conditions, catastrophic failure within the upper region of the primary shear zone occurs through either ductile fracture or large strain plastic deformation. Prior to the onset of chip segmentation, which occurs with increases in work material hardness and cutting speed, there is a transition in the morphology of the free surface of continuous chips, from the familiar lamellar structure to what has been termed a fold-type structure. This transition is attributed to the operation of thermally softened micro-shear zones, which, it is suggested, are a precursor to adiabatic shear initiation.
140 citations
TL;DR: The new developments in drilling technology are shown in the following paper as mentioned in this paper, where new drilling tool materials like carbides, cermets, ceramics and hard coatings have been developed in the last years with an dramatically increase of tool life and cutting parameters.
120 citations
Patent•
26 Jun 1997TL;DR: In this article, a process for producing phosgene is disclosed which involves contacting a mixture comprising carbon monoxide and chlorine (e.g., at about 300 °C or less) with carbon which has a micropore to macropore ratio of 3.5 or less; has a high degree of oxidative stability (i.e., loses about 16 % of its weight, or less, in the WVC Temperature Test as defined herein); and has a minimum surface area of at least 10 m2/g.
Abstract: A process for producing phosgene is disclosed which involves contacting a mixture comprising carbon monoxide and chlorine (e.g., at about 300 °C or less) with carbon which (1) has a micropore to macropore ratio of 3.5 or less; (2) has a high degree of oxidative stability (i.e., loses about 16 % of its weight, or less, in the WVC Temperature Test as defined herein); and (3) has a minimum surface area of at least 10 m2/g. The use of this carbon having an active metal content of 1000 ppm or more is disclosed.
114 citations
01 Oct 2006
TL;DR: In this article, the authors consider the environmental issues in machining and the fundamental concern is the use of cutting fluids, and they propose a method to reduce the use using cutting fluids.
Abstract: When considering the environmental issues in machining, the fundamental concern is the use of cutting fluids. Industry and research institutions are looking for ways to reduce the use of cu...
99 citations