Étude de l'usinabilité par fraisage d'un nouvel alliage d'aluminium MS43 à très haut pourcentage de silicium

Abstract

To satisfy the needs and performance of products, the aerospace industry increasingly needs to understand the behaviour of materials and their manufacturing processes, to ensure good machinability as well as high product performance and longer service life. In this sense, our study aims to investigate the tool / material interactions and their effects on surface integrity during milling of high silicon aluminum alloys as well as its machinability. The goal then is to optimize the cutting parameters in order to have a better surface integrity and ensure the functionality of the product. For this fact, specimens were milling under different cutting conditions (cutting speed and feed per tooth), and for different tool diameters in order to develop a global approach to predict surface roughness. Following an analysis, the results showed that the surface roughness increases with the increase of the feed rate and the cutting speed, which are the most significant parameters on the roughness. However, the increase in the feed per tooth intensified the roughness but with a lower contribution than the cutting speed. On the other hand, constraints with compressive tendencies in the direction of movement of the tool, and tensile stresses perpendicular to the direction of movement of the tool were perceived on the surface, increasing the cutting speed there is a point cutting parameters beyond which, the cutting forces increase enormously. It has been found that the cutting speed has a considerable effect on vibration, i.e. the increase of the cutting speed causes the vibration of the tool and therefore a decrease in the surface quality. A judicious choice of cutting speed and feed per tooth, allows a favourable tool operating condition with stable and moderate cutting forces and less vibration. Correlations were established between surface state, cutting forces, vibration and the cutting parameters. Based on a statistical analysis that takes into account the cutting forces, the vibration of the part and the microstructure defects, a recommendation of the optimal cutting parameters that favours the machinability of the MS43 alloy for different diameters of the tool was proposed. After validation tests, good agreement was observed between the predicted and measured values with a maximum error 14.25 % for the three samples.

Date	4 Jun 2018
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Victor Songmene (Supervisor) & Mohammad Jahazi (Co-supervisor)