https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Fri, 15 May 2026 02:15:59 GMT 2026-05-15T02:15:59Z http://hdl.handle.net/10985/24565 Development of a quick-stop device for micro-cutting PIQUARD, Romain; FONTAINE, Michaël; THIBAUD, Sébastien; GILBIN, Alexandre; LE COZ, Gaël; ALAIN, D'acunto Micro-cutting is characterised by undeformed chip thicknesses in the micron range. This range leaves little choice of in situ observation techniques. One solution is therefore to observe these zones a posteriori after the cutting has been abruptly interrupted. This technique has proven to be very useful for conventional machining. This paper deals with the development of a quick-stop device dedicated to micro-cutting. The aim of this device is to observe cutting mechanisms and chip formation at this scale in order to enhance micro-cutting models. Wed, 01 Nov 2023 00:00:00 GMT http://hdl.handle.net/10985/24565 2023-11-01T00:00:00Z PIQUARD, Romain FONTAINE, Michaël THIBAUD, Sébastien GILBIN, Alexandre LE COZ, Gaël ALAIN, D'acunto Micro-cutting is characterised by undeformed chip thicknesses in the micron range. This range leaves little choice of in situ observation techniques. One solution is therefore to observe these zones a posteriori after the cutting has been abruptly interrupted. This technique has proven to be very useful for conventional machining. This paper deals with the development of a quick-stop device dedicated to micro-cutting. The aim of this device is to observe cutting mechanisms and chip formation at this scale in order to enhance micro-cutting models. http://hdl.handle.net/10985/22295 Machinability of TiNb bio-compatible alloys COZ, Gaël Le; PELTIER, Laurent; PIQUARD, Romain; LAHEURTE, Pascal; ALAIN, D'acunto The success of biomedical implantation is linked to osseointegration, depending on the mechanical loading of the bone interface. The large difference in stiffness between the host bone (30 GPa) and the usual implant material (over 100 GPa), as well as the absence of mechanical stress at the surrounding bone, induce a stress shielding effect, which leads to bone atrophy and implant loss. A recent work has shown the possibility to produce so-called second-generation titanium alloys. β-type Ti alloys have been studied for biomedical applications, due to the composition of non-cytotoxic elements. Some TiNb alloys can reach after heat treatment a Young’s modulus close to 35 GPa, which is really close to bone’s one. Unfortunately, titanium and its alloys are well known for their poor machinability due to the hardness and low thermal conductivity. Machined surfaces of titanium alloys are also easily damaged (micro cracks, build-up edge, plastic deformation, heat-affected zones, and tension residual stresses) during the process. Studying process parameters is important to avoid these phenomena. The machinability of TiNb (turning, milling) has not been studied to date. Therefore, in this study, we examined the behavior of the TiNb titanium alloy for applications as a biomaterial in micro-cutting. Orthogonal cutting tests were performed on austenite and martensite states TiNb alloys and compared with Ti40 pure titanium. The aim was to evaluate the influence of the alloys and the cutting parameters on the evolution of the cutting forces, specific cutting energy, friction coefficient which are good indicators of machinability. Sat, 01 Jan 2022 00:00:00 GMT http://hdl.handle.net/10985/22295 2022-01-01T00:00:00Z COZ, Gaël Le PELTIER, Laurent PIQUARD, Romain LAHEURTE, Pascal ALAIN, D'acunto The success of biomedical implantation is linked to osseointegration, depending on the mechanical loading of the bone interface. The large difference in stiffness between the host bone (30 GPa) and the usual implant material (over 100 GPa), as well as the absence of mechanical stress at the surrounding bone, induce a stress shielding effect, which leads to bone atrophy and implant loss. A recent work has shown the possibility to produce so-called second-generation titanium alloys. β-type Ti alloys have been studied for biomedical applications, due to the composition of non-cytotoxic elements. Some TiNb alloys can reach after heat treatment a Young’s modulus close to 35 GPa, which is really close to bone’s one. Unfortunately, titanium and its alloys are well known for their poor machinability due to the hardness and low thermal conductivity. Machined surfaces of titanium alloys are also easily damaged (micro cracks, build-up edge, plastic deformation, heat-affected zones, and tension residual stresses) during the process. Studying process parameters is important to avoid these phenomena. The machinability of TiNb (turning, milling) has not been studied to date. Therefore, in this study, we examined the behavior of the TiNb titanium alloy for applications as a biomaterial in micro-cutting. Orthogonal cutting tests were performed on austenite and martensite states TiNb alloys and compared with Ti40 pure titanium. The aim was to evaluate the influence of the alloys and the cutting parameters on the evolution of the cutting forces, specific cutting energy, friction coefficient which are good indicators of machinability. http://hdl.handle.net/10985/22921 Study of the Influence of Cutting Edge on Micro Cutting of Hardened Steel Using FE and SPH Modeling CHAABANI, Lobna; PIQUARD, Romain; ABNAY, Radouane; FONTAINE, Michaël; GILBIN, Alexandre; PICART, Philippe; THIBAUD, Sébastien; DUDZINSKI, Daniel; ALAIN, D'acunto Micromachining allows the production of micro-components with complex geometries in various materials. However, it presents several scientific issues due to scale reduction compared to conventional machining. These issues are called size effects. At this level, micromachining experiments raise technical difficulties and significant costs. In this context, numerical modeling is widely used in order to study these different size effects. This article presents four different numerical models of micro-cutting of hardened steel, a Smooth Particle Hydrodynamics (SPH) model and three finite element (FE) models using three different formulations: Lagrangian, Arbitrary Eulerian-Lagrangian (ALE) and Coupled Eulerian-Lagrangian (CEL). The objective is to study the effect of tool edge radius on the micro-cutting process through the evolution of cutting forces, chip morphology and stress distribution in different areas and to compare the relevance of the different models. First, results obtained from two models using FE (Lagrangian) and SPH method were compared with experimental data obtained in previous work. It shows that the different numerical methods are relevant for studying geometrical size effects because cutting force and stress distribution correlate with experimental data. However, they present limits due to the calculation approaches. For a second time, this paper presents a comparison between the four different numerical models cited previously in order to choose which method of modeling can present the micro-cutting process. Fri, 01 Jul 2022 00:00:00 GMT http://hdl.handle.net/10985/22921 2022-07-01T00:00:00Z CHAABANI, Lobna PIQUARD, Romain ABNAY, Radouane FONTAINE, Michaël GILBIN, Alexandre PICART, Philippe THIBAUD, Sébastien DUDZINSKI, Daniel ALAIN, D'acunto Micromachining allows the production of micro-components with complex geometries in various materials. However, it presents several scientific issues due to scale reduction compared to conventional machining. These issues are called size effects. At this level, micromachining experiments raise technical difficulties and significant costs. In this context, numerical modeling is widely used in order to study these different size effects. This article presents four different numerical models of micro-cutting of hardened steel, a Smooth Particle Hydrodynamics (SPH) model and three finite element (FE) models using three different formulations: Lagrangian, Arbitrary Eulerian-Lagrangian (ALE) and Coupled Eulerian-Lagrangian (CEL). The objective is to study the effect of tool edge radius on the micro-cutting process through the evolution of cutting forces, chip morphology and stress distribution in different areas and to compare the relevance of the different models. First, results obtained from two models using FE (Lagrangian) and SPH method were compared with experimental data obtained in previous work. It shows that the different numerical methods are relevant for studying geometrical size effects because cutting force and stress distribution correlate with experimental data. However, they present limits due to the calculation approaches. For a second time, this paper presents a comparison between the four different numerical models cited previously in order to choose which method of modeling can present the micro-cutting process. http://hdl.handle.net/10985/9938 Micro-end milling of NiTi biomedical alloys, burr formation and phase transformation PIQUARD, Romain; ALAIN, D'acunto; LAHEURTE, Pascal; DUDZINSKI, Daniel This paper focuses on burr formation in micro-end milling of two Nickel-Titanium shape memory alloys (SMA), an austenitic and a martensitic NiTi. Phase transformation during machining was also examined. The experimental design approach was used to study the effect of cutting parameters on burr formation. The studied parameters were cutting speed, feed per tooth, depth and width of cut, 20 machining strategy and initial material phase of the NiTi alloy. Different types of burrs were formed during micro-end milling of NiTi alloys; it was observed that top burrs are the most important. The height of top burrs can reach values close to those of the depth of cut. Burrs were observed and characterized using a Scanning Electron Microscope (SEM), confocal and optical microscopes. The affected layer under the machined surface, and phase transformation 25 were investigated by using SEM. The results of the analysis of variance showed a significant formation of burrs, deeply influenced by the feed per tooth and width of cut. An increase in the feed per tooth and a decrease of width of cut tend to decrease the height and width of the top burr. In a thin layer under the machined surface, phase transformation was observed for the martensitic NiTi. Wed, 01 Jan 2014 00:00:00 GMT http://hdl.handle.net/10985/9938 2014-01-01T00:00:00Z PIQUARD, Romain ALAIN, D'acunto LAHEURTE, Pascal DUDZINSKI, Daniel This paper focuses on burr formation in micro-end milling of two Nickel-Titanium shape memory alloys (SMA), an austenitic and a martensitic NiTi. Phase transformation during machining was also examined. The experimental design approach was used to study the effect of cutting parameters on burr formation. The studied parameters were cutting speed, feed per tooth, depth and width of cut, 20 machining strategy and initial material phase of the NiTi alloy. Different types of burrs were formed during micro-end milling of NiTi alloys; it was observed that top burrs are the most important. The height of top burrs can reach values close to those of the depth of cut. Burrs were observed and characterized using a Scanning Electron Microscope (SEM), confocal and optical microscopes. The affected layer under the machined surface, and phase transformation 25 were investigated by using SEM. The results of the analysis of variance showed a significant formation of burrs, deeply influenced by the feed per tooth and width of cut. An increase in the feed per tooth and a decrease of width of cut tend to decrease the height and width of the top burr. In a thin layer under the machined surface, phase transformation was observed for the martensitic NiTi. http://hdl.handle.net/10985/10200 Study of elementary micro-cutting in hardened tool steel PIQUARD, Romain; GILBIN, Alexandre; FONTAINE, Michaël; ALAIN, D'acunto; THIBAUD, Sébastien; DUDZINSKI, Daniel In order to model micro-milling cutting forces, a way is to apply a local model on discretized elements of the cutting edge and then summing on the whole edge to obtain the global cutting forces. This local model is usually obtained by numerical simulation or cutting experimentation. This paper focuses on orthogonal and oblique micro-cutting experiments of AISI 6F7 with tungsten carbide tools. Results show the influence of cutting edge sharpness on cutting forces and the existence of different mechanisms corresponding to different ranges of uncut chip thickness values. A phenomenological model has been identified to model correctly these zones. Then, by comparing experimental micro-milling forces with those deduced from these micro-cutting model and tests, a good agreement has been found. In order to complete this study, phenomenological and thermo mechanical models are being developed. The aim is to obtain an elementary cutting model that can be used for micro-milling simulation and optimization. Wed, 01 Jan 2014 00:00:00 GMT http://hdl.handle.net/10985/10200 2014-01-01T00:00:00Z PIQUARD, Romain GILBIN, Alexandre FONTAINE, Michaël ALAIN, D'acunto THIBAUD, Sébastien DUDZINSKI, Daniel In order to model micro-milling cutting forces, a way is to apply a local model on discretized elements of the cutting edge and then summing on the whole edge to obtain the global cutting forces. This local model is usually obtained by numerical simulation or cutting experimentation. This paper focuses on orthogonal and oblique micro-cutting experiments of AISI 6F7 with tungsten carbide tools. Results show the influence of cutting edge sharpness on cutting forces and the existence of different mechanisms corresponding to different ranges of uncut chip thickness values. A phenomenological model has been identified to model correctly these zones. Then, by comparing experimental micro-milling forces with those deduced from these micro-cutting model and tests, a good agreement has been found. In order to complete this study, phenomenological and thermo mechanical models are being developed. The aim is to obtain an elementary cutting model that can be used for micro-milling simulation and optimization. http://hdl.handle.net/10985/9936 Expérimentation de la micro-coupe élémentaire sur un acier dur et comparaison au micro-fraisage PIQUARD, Romain; GILBIN, Alexandre; ALAIN, D'acunto; FONTAINE, Michaël; DUDZINSKI, Daniel; THIBAUD, Sébastien Cet article présente des essais de micro-coupe orthogonale et oblique à partir de tournage sur un acier 40NiCrMo16. Les résultats obtenus démontrent l’influence du rayon d’acuité d’arête sur les efforts mesurés notamment aux faibles épaisseurs de copeau non déformé. Les efforts spécifiques de coupe déduits sont en cohérence avec ceux obtenus lors d’essais de micro-fraisage issus de travaux précédents. Pour compléter l’étude, cet article pose les bases de la modélisation phénoménologique et thermomécanique adaptée à la micro-coupe. Le but à terme est d’obtenir un modèle de coupe élémentaire utilisable dans le cas du micro-fraisage puis de comparer les résultats obtenus aux résultats expérimentaux. Wed, 01 Jan 2014 00:00:00 GMT http://hdl.handle.net/10985/9936 2014-01-01T00:00:00Z PIQUARD, Romain GILBIN, Alexandre ALAIN, D'acunto FONTAINE, Michaël DUDZINSKI, Daniel THIBAUD, Sébastien Cet article présente des essais de micro-coupe orthogonale et oblique à partir de tournage sur un acier 40NiCrMo16. Les résultats obtenus démontrent l’influence du rayon d’acuité d’arête sur les efforts mesurés notamment aux faibles épaisseurs de copeau non déformé. Les efforts spécifiques de coupe déduits sont en cohérence avec ceux obtenus lors d’essais de micro-fraisage issus de travaux précédents. Pour compléter l’étude, cet article pose les bases de la modélisation phénoménologique et thermomécanique adaptée à la micro-coupe. Le but à terme est d’obtenir un modèle de coupe élémentaire utilisable dans le cas du micro-fraisage puis de comparer les résultats obtenus aux résultats expérimentaux. http://hdl.handle.net/10985/10270 Study of burr formation and phase transformation during micro-milling of NiTi alloys PIQUARD, Romain; ALAIN, D'acunto; DUDZINSKI, Daniel Micro-milling can be defined as milling with end mills smaller than 1 mm of diameter. The top-down approach from milling to micro-milling is often used to define cutting conditions. Unfortunately geometries either for the active part or the overall shape are quite different from conventional tools, leading to inexistent problems at the macro-scale, such as a larger cutting edge radius to uncut chip thickness ratio leading to ploughing effect. Moreover, micro-milling can be used on particular material such as shape memory alloys in biomedical domain which are difficult to machine. This study focuses on burr formation during shoulder milling for two biocompatible NiTi alloys: a martensitic NiTi (shape memory effect) and an austenitic one (pseudo-elasticity effect). Design of experiment is used to highlight the influence of various parameters (cutting parameters and material phases) on the burr formation in micro-milling NiTi alloys. Burrs were observed and measured using confocal, optical and electronic microscopy and tend to be as large as shoulders dimensions. Material phase transformation was also examined. Analysis of variance emphasizes that the larger the feed per tooth and the smaller the width of cut are, the smaller the top burr is. Cutting strategy leads to different burr shape: up-milling burrs have a large curvature, whereas down-milling burrs are slightly bent. An affected layer of about 10 μm has been observed for the austenitic NiTi. The proposed experimental approach give the opportunity to study burr formation in micro-milling, the machinability of alloys or superelastic NiTi shape memory and a qualitative explanation of burr formation has been developed. Wed, 01 Jan 2014 00:00:00 GMT http://hdl.handle.net/10985/10270 2014-01-01T00:00:00Z PIQUARD, Romain ALAIN, D'acunto DUDZINSKI, Daniel Micro-milling can be defined as milling with end mills smaller than 1 mm of diameter. The top-down approach from milling to micro-milling is often used to define cutting conditions. Unfortunately geometries either for the active part or the overall shape are quite different from conventional tools, leading to inexistent problems at the macro-scale, such as a larger cutting edge radius to uncut chip thickness ratio leading to ploughing effect. Moreover, micro-milling can be used on particular material such as shape memory alloys in biomedical domain which are difficult to machine. This study focuses on burr formation during shoulder milling for two biocompatible NiTi alloys: a martensitic NiTi (shape memory effect) and an austenitic one (pseudo-elasticity effect). Design of experiment is used to highlight the influence of various parameters (cutting parameters and material phases) on the burr formation in micro-milling NiTi alloys. Burrs were observed and measured using confocal, optical and electronic microscopy and tend to be as large as shoulders dimensions. Material phase transformation was also examined. Analysis of variance emphasizes that the larger the feed per tooth and the smaller the width of cut are, the smaller the top burr is. Cutting strategy leads to different burr shape: up-milling burrs have a large curvature, whereas down-milling burrs are slightly bent. An affected layer of about 10 μm has been observed for the austenitic NiTi. The proposed experimental approach give the opportunity to study burr formation in micro-milling, the machinability of alloys or superelastic NiTi shape memory and a qualitative explanation of burr formation has been developed.