Influence du traitement thermique sur l'usinabilité du laiton monophasé

Abstract

Knowledge of the properties and behavior of a material in machining is essential to optimize its use and maximize his machinability. For this purpose, the study of the modification of ductility by heat treatment on several machinability criteria such as cutting forces, surface roughness, burrs and chip formation was conducted on single-phase brass. First, the influence of heat treatment on the microstructure of brass was investigated. Grain size and hardness have helped determining the mechanical properties of materials conditions. Then drilling tests were performed on H01 (99HV), OS100 (88HV) and OS250 (47HV) tempers to study the influence of heat treatment on machinability. This experimental study allowed to understand the influence of rolling reduction and annealing temperature on mechanical properties. Machinability tests were then used to prove that the cutting forces are dependent on cutting conditions but not the ductility of tempers tested. The size of burrs increases with the cutting speed and the ductility, but decreases with feed. The surface roughness of the holes after machining was also studied. It was also demonstrated by a study on the chips that the temperature increases with the cutting speed, which causes a change in the form of chips. The chip segmentation analysis has however failed to show a correlation with the tested heat treatments. Finally, the coating of the tool has shown significant influence on the machinability of the material. The machinability of C26000 (CuZn30) brass was found better when machining in a hard temper. These conclusions apply to the studied single phase brass. It would be interesting to investigate the case of biphasic brass.

Date	22 Aug 2014
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Victor Songmene (Supervisor) & Jacques Masounave (Co-supervisor)