49 / 2021-06-29 16:20:51

Experimental Investigation of Cubic Boron Nitride Magnetic Abrasive Powders for Polishing Ti-6Al-4V

Magnetic abrasive finishing, Cubic boron nitride particle, Ti-6Al-4V

Ti-6Al-4V is widely used in the aerospace field owing to its high strength and low density. However, its high chemical activity will cause serious adhesion between chip and tool in the process of machining. In this paper, a novel bonded magnetic abrasive powder (MAP) applied in the magnetic abrasive finishing (MAF) is developed to finish the Ti-6Al-4V. Fine cubic boron nitride (CBN) particles were used as abrasive phase of MAP. The development of CBN MAPs was made via the gas atomization technique. In the MAF process, four process parameters like working gap, rotational speed, feed rate of workpiece and mesh number of MAP were considered as influence factors. A five-level and four-factor central composite design experiment was carried out to verify the polishing performance of developed MAPs on the finishing of Ti-6Al-4V workpiece. The analysis data was used to understand different interactions of significant parameters. A regression model for predicting the change of surface roughness was obtained and the optimal parameter combination was figured out through solution of quadratic equation in Design-Expert software. CBN particles with high hardness, excellent thermal conductivity, and poor affinity with titanium alloy produced a smooth surface on Ti-6Al-4V workpiece. The surface roughness was improved by over 80% at optimum parameters. The atomized CBN MAPs give the Ti-6Al-4V a nano-level surface finish.