International audienceThis article proposes a simulation of cutting forces in broaching of fir tree slots. Every step needed to build an in-house fir tree broaching simulation is presented. This simulation is based on the discretization of each tooth of the broach, computation of elementary cutting forces of each discretized section, and finally the summation of each elementary cutting force into a global axes system. This work also presents orthogonal cutting experiments to implement realistic specific cutting forces into the model. The simulation obtained is compared with the real force signals of a fir tree broach to evaluate the quality of the simulation. At the end, the application to industrial context is developed
In order to reveal the effect of oxidation on thin blade walls, a new machine allowing tests up to 1250°C under controlled atmosphere has been designed. Creep tests were performed on MC2 single crystal superalloy at 1150°C, under hydrogenated argon and dry air, but also with a switch from one atmosphere to the other after reaching the steady state creep stage. The results point out the decrease of the minimum creep rate in case of tests performed or at least started under hydrogenated argon, compared with the value obtained under synthetic dry air. This effect of oxidation was attributed to the protective oxide scale formed under hydrogenated argon. The low growth rate of alumina layer leads to a thinner zone affected by metal consumption, which is assumed to be non bearing, and prevents from vacancy flux toward the alloy. The second point results in slowing down creep mechanisms controlled by diffusion and therefore dislocation motion and microstructure evolution. Thermogravimetric tests confirm the difference of oxidation kinetics regards to environment (hydrogenated argon and dry air). However, oxide scales have different microstructures on thermogravimetric and creep samples when tested under air.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.