Investigation on Cutting Feasibility on Ni-CBN on HSS Substrates for Aerospace Material

Abstract

The study involves coating the high-speed steel (HSS) tool with cubic Boron via electroless nickel co-deposition. The surface coating of Ni-CBN was deposited via electroless nickel where the process of involved chemical reactions as the ceramic CBN powders was embedded within the layer. By introducing the electroless nickel process, the coating cost and procedure could be simplified. The electroless deposition has been extensively practised in industry, and the most prevalent coating offers excellent corrosion, wear and abrasion resistance, ductility, lubricity, electrical properties, and hardness. Thus, the introduction of the new electroless nickel (Ni-CBN) tools can be a contribution to the industry. This paper discussed on comparing the performance of Nickel-cubic boron nitride (Ni-CBN) HSS tool substrates and with uncoated HSS tool for its surface tolerance in milling of Aluminium Alloy 7075. The process variables selected during experimentation based on Taguchi L9 are cutting speed, feed rate, and depth of cut with three different levels for each parameter. Result shows, the lowest flank wear for coated measured is 51.34 μm while the highest is 380.26 μm. The highest surface roughness for uncoated is 1.154 μm and lowest 0.42μm. Meanwhile, for coated substrates, the highest Ra is 0.787μm and lowest 0.251μm. At the end of the analysis, the Ni-CBN HSS cutting tools are generally able to slightly reduce the tool wear with the longest tool lifetime 195 minutes compared uncoated 143 minutes. Therefore, it is concluded that the Ni-CBN HSS tool end mill are generally able to reduce the tool wear.