Optimization of drilling parameters for aluminum metal matrix composite using entropy-weighted TOPSIS under MQL conditions

The aim of the present work is to understand the effect of drilling parameters (drill speed and feed rate) during the drilling of a Saffil fiber-reinforced Al metal matrix composite (MMC) under minimum quantity lubrication (MQL) condition. The effect of drilling parameters on individual response characteristics is evaluated and the optimum drilling parameters are also investigated using a multi-response optimization technique known as the entropy-weighted technique for order performance by similarity to ideal solution (EWTOPSIS). The drilling parameter optimization is performed with the aim of minimizing surface roughness in the drilled hole, roundness error in the drilled hole and feed force during drilling. The drilling parameters have a significant effect on individual responses. Weights were assigned to each response using the entropy weight method, and closeness coefficients were calculated to obtain the optimal level for the drilling parameters. A drill speed of 11 m/min and a feed rate of 0.05 mm/rev are the optimal combination to minimize the desired output responses simultaneously

Biomaterials in hip joint replacement

Total hip joint replacement is unavoidable in the orthopedic application, for improving the quality of patient life suffering from arthritis. Replacing damaged joint with artificial joint gaining popularity and it became a need in such cases. While joint replacement represents success stories in the field of orthopedic surgery, but maintaining implant for last long is still challenge. The average lifespan of hip joint replacement is about 15 years. Last 50 years research in the field of orthopedics trying to evaluate the biomaterials for hip joint replacement with improved performance in terms of extending joint life. In early days different kind of natural materials like wood, glue, rubber, tissue from living forms and manufactured materials like iron, gold and zinc were used as biomaterials based on trial and error. Biomaterials are such materials which are intended to replace a part or function of the body in reliably economically and physiologically acceptable manner. The aim of this review is to present the overall evaluation of biomaterials mainly developed for a hip joint replacement from early days to current days. In this paper attempt has been made to summarize the evolution of the biomaterial from early days of metals, polymers to present days of ceramics commonly used in the field of orthopedic for hip joint replacement