Development and experimental investigation of magnetic abrasive finishing of 17-4PH steel

Abstract

Magnetic abrasive finishing (MAF) is a promising process for achieving better surface finish, not only on softer materials, but also on harder materials. In several industries, 17-4PH steel has predominantly being used due to its exceptional properties of better corrosion resistance, high strength-to-weight ratio, and ease of weldability. In this article, the details of a developed MAF attachment for a CNC vertical milling machine are presented. The developed attachment was used to finish the surface of 17-4PH steel and is suitable for plane workpiece surface. Effect of various MAF process parameters such as rotational speed of electromagnet, supply voltage/current, abrasive mesh number, and working gap were studied on 17-4PH steel for material removal rate (MRR) and percentage change in surface roughness (PCSR) using one-factor) using one-factor-at-a-time approach (OFAT). Based on experimental results, on increasing voltage/current, increase in MRR and PCSR was observed; however, decrease in PCSR and MRR was noticed with increase in the working gap. PCSR was increased up to 600 rpm of electromagnet and 600 mesh number. However, on further increase in speed and mesh number, resulted in decrease in PCSR. Supply voltage/current was the most significant input process parameter on PCSR for the constant values of others parameters. Maximum PCSR of 90.37% was observed at 1.5 mm working gap, 600 rpm rotational speed, 600 mesh number and 24 V/0.9A voltage/current. The results reported in the article are useful in identifying the relative significance of parameters for the selected workpiece material.