Magneto-Rheological Fluid Assisted Abrasive Nanofinishing of ß-Phase Ti-Nb-Ta-Zr Alloy: Parametric Appraisal and Corrosion Analysis.

The present work explores the potential of magneto-rheological fluid assisted abrasive finishing (MRF-AF) for obtaining precise surface topography of an in-house developed ß-phase Ti-Nb-Ta-Zr (TNTZ) alloy for orthopedic applications. Investigations have been made to study the influence of the concentration of carbonyl iron particles (CIP), rotational speed (Nt), and working gap (Gp) in response to material removal (MR) and surface roughness (Ra) of the finished sample using a design of experimental technique. Further, the corrosion performance of the finished samples has also been analyzed through simulated body fluid (SBF) testing. It has been found that the selected input process parameters significantly influenced the observed MR and Ra values at 95% confidence level. Apart from this, it has been found that Gp and Nt exhibited the maximum contribution in the optimized values of the MR and Ra, respectively. Further, the corrosion analysis of the finished samples specified that the resistance against corrosion is a direct function of the surface finish. The morphological analysis of the corroded morphologies indicated that the rough sites of the implant surface have provided the nuclei for corrosion mechanics that ultimately resulted in the shredding of the appetite layer. Overall results highlighted that the MRF-AF is a potential technique for obtaining nano-scale finishing of the high-strength ß-phase Ti-Nb-Ta-Zr alloy.

The Effect of an External Magnetic Field on the Aspect Ratio and Heat Input of Gas-Metal-Arc-Welded AZ31B Alloy Weld Joints Using a Response Surface Methodology.

This study attempted to analyze and optimize the effect of an external magnetic field (EMF) on the aspect ratio and heat input for AZ31B weld joints that were welded using the gas metal arc welding (GMAW) process. The response surface methodology (RSM) was adopted for the critical analysis, and subsequently, mathematical models were developed based on the experimental results. It was observed that the EMF and its interaction with the wire feed rate significantly affected the aspect ratio and heat input, respectively. At 119 G (magnetic field), 700 mm/min (welding speed), 5.8 m/min feed rate, and 11.5 L/min (gas flow rate), the aspect ratio was 2.26, and the corresponding heat input factor (HIf) was 0.8 with almost full weld penetration.