Optimal parameters of abrasive flow finishing for hip joint implants

Abstract

Total hip arthroplasty (THA) is one of the most well-known orthopedic surgeries in the world which involves the substitution of the natural hip joint by prostheses. In this process, the surface roughness of the femoral head plays a pivotal role in the performance of hip joint implants. In this regard, the nano-finishing of the femoral head of the hip joint implants to achieve a uniform surface roughness with the lowest standard deviation is a major challenge in the conventional and advanced finishing processes. In the present study, the inverse replica fixture technique was used for automatic finishing in the abrasive flow finishing (AFF) process. For this aim, an experimental setup of the AFF process was designed and fabricated. After the tests, experimental data were modeled and optimized to achieve the minimum surface roughness in the ASTM F138 (SS 316L) femoral head of the hip joint through the use of response surface methodology (RSM). The results confirmed uniform surface roughness up to the range of 0.0203 µm with a minimum standard deviation of 0.00224 for the femoral head. Moreover, the spherical shape deviation of the femoral head was achieved in the range of 7 µm. The RSM results showed a 99.71% improvement in the femoral head surface roughness (0.0007) µm under the optimized condition involving the extrusion pressure of 9.10 MPa, the number of finishing cycles of 95, and SiC abrasive mesh number of 1000.

Research on the mechanism of particles separation in magnetorheological fluid-based finishing process

“…Kim et al 13 determined the optimum MRF condition for finishing of BK7 glass by varying carrier wheel speed and electromagnetic current and observed that influence function depth increased with increase in carrier wheel speed using different slurry compositions. Choopani et al 14 used the inverse replica fixture technique to finish a femoral head made of a hip joint using an abrasive flow finishing (AFF) setup and reported 99.71% reduction in surface roughness at extrusion pressures of 9.10 MPa, 1000 mesh size of SiC abrasives and 95 finishing cycles. On continuously increasing the rotating speed, Gheisari et al 15 noticed an optimum level of surface roughness with reference to wheel rotation speed.…”

Finishing nonuniformity for electrical discharge machined closed complicated flow channels by abrasive flow machining

“…Results showed that high finishing uniformity was obtained. 21 The finishing nonuniformity for additively manufactured metal components with variable cross-section flow channels by AFM was studied by Kum et al Results showed that material removal at the necking region with a smaller cross section was much larger than that at other regions with a more spacious cross section. It is believed that when the abrasive medium flows in a channel with decreasing cross section, its wall-slip velocity increases gradually, thus local material removal rate increases, and finishing nonuniformity takes place.…”

Ultrasonic vibration assisted double disc chemo-magnetorheological finishing of silicon wafer: Experimental investigations and optimization for surface roughness

“…5 On the other hand, advanced finishing processes like magnetic abrasive finishing (MAF) and magnetorheological finishing (MRF) are effectively used to achieve a desired surface finish over the brittle work surface. 6,7 Several authors have started exploring these processes for fragile materials. Jain et al 8 investigated the performance of bonded magnetic-abrasive particles for abrasive finishing.…”