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Often, surface mechanical treatment (SMT) or heat (quenching, tempering) is used to improve the surface condition and mechanical characteristics such as impact resistance and tensile strength. Hence the objective of this experimental work, where ball burnishing (BB) as well as quenching and tempering were applied on S355 JR steel specimens, is to evaluate the surface hardness Hv, the rupture strength Rm, the energy absorbed W during the impact test, and the work-hardened thickness e after the burnishing operation. Factorial designs were used for the test organization and mathematical models were established for the prediction of Hv, Rm, W, and “e” in function on treatment parameters considered: number of tool passes (i) and the pressure force (Py). The results show that the surface hardness increases by 30.46%. The high levels of Py and i were allowed to improve Rm by 30.8% as well as an increase in tenacity of only 3.6%. Increasing the force to 20kgf promotes mixed rupture under the effect of impact to shock. The quenching and tempering improve the Rupture strength Rm by 183% and 119%, respectively, while the effect of burnishing was limited to a rate of increase of this property of 28% compared to machining.

The objective of this work is to identify the most influential parameters on the friction coefficient and wear rate, using the response surface method. The friction tests were carried out by adopting the methodology of complete planes 23at three factors ("D", "V" et "Py"), at two level for each factor. The results show a decrease in the wear rate when the three factors are at their highest level and a decrease in the friction coefficient when using minimum loads and speeds on important distances. In addition, the developed mathematical models make it possible to reveal a correlation between the test parameters and the responses studied in their studied domain. An evaluation of the volume parameters "Vmc" and "Vvv" was carried out. The morphology of the worn surface shows that the friction under a load of 1 N leads to the predominance of an abrasive wear mechanism, while a load of 10 N favors an adhesive wear mechanism, increasing the parameters "Vmc" and "Vvv" to the maximum.

This study aims, the evaluation of the surface quality by the fractal dimension "D" and volume settings (Vmp, Vmc, Vvv). Experimental work was conducted by process of surface mechanical treatment; in this case ball burnishing was applied on a commercial aluminum alloy material. Three parameters of regime were considered: "burnishing feed f", "burnishing force Py" and "burnishing ball diameter Db". Mathematical models wereidentified using the plans of multifactorial experiments "Box-Behnken" for prediction of fractal dimension "D" and volume parameters. Experimental and simulation results have enabled to show than the large diameter ball under low loads and medium feed speeds, favors the elimination of peaks and reduction of fractal dimension whence quality improvement of surface.Keywords: burnishing, volume parameters, fractal dimension, experimental designs

La stabilité du processus de coupe est une condition fondamentale pour l’obtention de bons résultats d’usinage qui sont souvent traduits par l’amélioration de la qualité des surfaces usinées, l’augmentation de la durée de vie de l'outil de coupe et le bon fonctionnement des machines-outils. Il est établi que la variation des paramètres de coupe participe à perturber ce critère. L’étude proposée consiste justement à développer une approche d’appréciation de la stabilité qui combine à la fois la simulation, basée sur la théorie des lobes de stabilité, et le traitement des paramètres vibratoires (RMS et accélérations) relevés et calculés, avec le principe de détermination des valeurs limites de stabilité - instabilité de ces paramètres vibratoires.Mots clés : usinage, rigidité du système d’usinage, optimisation des paramètres de coupe, lobes de stabilité, vibrations des machines-outils.Study of the stability of the machining process based on the stability lobes theory and treatment of vibration parameters - milling caseStability of the cutting process is a basic requirement of good machining process. For ensuring these guarantees an improvement in surface roughness, an increase in the life of cutting tools and the smooth operation of machine tools is necessary. It is established that various cutting parameters disturbs this criterion. The purpose of this study is to develop an approach to assess machining stability. Simulation based on stability lobe theory, and also by processing the vibration parameters (Root Mean Square and acceleration values), were combined to determine the stability/instability borderline values of the vibration parameters.Keywords: machining, machining system rigidity, cutting parameters optimization, stability lobes, machine tools vibration.

Colloque avec actes et comité de lecture. Internationale.; International audience; Assurer la fonction de production est de produire en temps voulu, les quantités demandées par les clients tout en respectant le cout et la qualité des produits fabriqués. A cet effet, l'optimisation des paramètres de coupe est très importante pour le contrôle de la rugosité des surfaces usinées, ainsi que, le diagnostic et la surveillance du processus d'usinage, dans le but d'améliorer l'entretien préventif. L'objectif de la présente étude est d'optimiser les paramètres de coupe ainsi que l'analyse de la rugosité de surface en utilisant la méthode de Taguchi.

Colloque avec actes et comité de lecture. Internationale.; International audience; La surveillance vibratoire constitue une technique de contrôle non destructif très utilisée dans le secteur industriel, l'automatisation de son utilisation représente un gain important pour une meilleure maintenabilité des machines. Dans ces travaux nous allons proposer une démarche pour améliorer le diagnostic automatique d'une machine industrielle tournante par une sélection du vecteur d'entrée, a partir d'indicateurs extraits des signaux vibratoire. Des techniques de l'intelligence artificielle vont être utilisées a la fois au niveau de la sélection d'entrées et de la prise de décision.

316L is a type of austenitic stainless steel that offers a good combination of mechanical properties, corrosion resistance, and biocompatibility. In some industrial applications, it is necessary to proceed to finish treatments to extend the lifetime of the mechanical parts. In the present chapter, ball burnishing treatment is applied to improve the surface integrity of 316L since the performance behavior of parts is directly dependant on the surface properties of the used material. Both surface topography and surface microhardness of 316L after subjection to ball burnishing are studied. The number of burnishing passes is varied by up to five to investigate its effect on the results. Optical profilometer and atomic force microscopy (AFM) were used to analyze the surface roughness and surface topography texture while measurements of microhardness Vickers were proceeded to investigate the changes in surface hardening.