Surface Characterization of AD730^TM Part Produced in High Speed Turning with CBN tool

AD730^TM is a novel superalloy developed for the hot section part in aero engine and gas turbine machinery with enhanced performance. The material is characterized by its excellent high temperature properties for being an alloy possible to manufacture by cast and wrought process compared to other superalloys in the same class such as Inconel718. The material with higher temperature capability means potentially increased energy efficiency as well as less emission in the new engine design. However, there is lack of information on machinability of the material, especially achievable surface quality under high speed machining. Machining process is commonly employed in the manufacturing of hot section part, such as turbine disc, to obtain the final surface quality and tolerance. Surface quality produced by the machining processes is one of the crucial factors to determine the functional performance and correspondent fatigue life time of the parts. The paper will present the results of surface characterization of the part produced by high speed turning with CBN tool. A series machining tests were conducted in the study. Surface morphology on machined samples were investigated with a scanning electron microscope to assess the surface damages and other surface defects induced by the machining processes. 3D surface topology was also analyzed with an Infinite-focus-variant microscope to correlate with machining condition. In addition, effect of tool wear and cutting parameters, such as cutting speed, will also be discussed in the paper.