چكيده به لاتين
Considering the ever-increasing expansion of technology and the need to make parts with excellent surface finish on the nano scale and considering the inability of traditional processes to achieve such surface finish, especially in the case of parts with complex dimensions and shapes, the approach of research centers, Nuclear industry, air and space, manufacturing of semiconductors, etc. is towards new processes and free from surface defects. Among these new processes, we can mention the finishing process with abrasive flow. In this method, by applying force on the cutting tool (Media) and pressing it on the desired surface and creating a relative movement between the tool and the workpiece, surface finishing is done. This method is generally used to pay internal surfaces and generally for surfaces that cannot be paid in a traditional way. In this research, the mesh of abrasive particles in three levels (100, 200, 325), the number of working cycles of the mechanism in three levels (80, 100 and 150 cycles) and the hardness of the work piece according to the steel and aluminum materials respectively (45 HRC and (40 HB) are considered as input parameters in the nano-polishing of steel (ASTM A 1003) and aluminum (USA 8112) and their effect on the surface roughness has been investigated experimentally. In this research, the samples (tube after various machining operations and mechanism construction, their internal surfaces have been polished with the abrasive flow process. The surface roughness parameter (Ra) was measured by a roughness meter before and after the machining process. Also, in order to investigate the factors affecting the process, the design of experiment (DOE) and MINITAB 16 software were used. In the last step, the machining surfaces before and after the process were imaged by scanning electron microscope (SEM) in order to check the surface texture changes. It shows that increasing the mesh of particles (shrinking of abrasive particles) causes a decrease in surface roughness and loading rate, on the other hand, increasing the number of working cycles to a certain extent causes an increase in material removal rate and improves surface smoothness. The loading rate in the workpiece with a harder material (steel) is lower than the softer one (aluminum) and in the same polishing conditions, the harder workpiece has a better surface finish than the softer workpiece.
