Influence of surface micro-textured and coating on tungsten carbide tools in turning of aluminum alloy 7075-T6

Aluminum alloy 7075-T6, valued for its lightweight properties, high strength, and corrosion resistance, is widely used in the aerospace and automotive industries; however, it poses machining challenges, including the formation of built-up edges, tool wear, and heat-induced microstructural changes. These coatings degrade tool geometry and surface finish in turning operations. This study introduces a novel surface engineering approach that combines laser-induced micro-textures with a TiAlCr (C, N) nanostructured coating on tungsten carbide (WC–Co) tools to enhance turning performance. Micro-textures, created via a fiber laser (20 W, 1064 nm) with triangular grooves (100 μm depth, 150 μm pitch), were applied parallel to the cutting edge on the rake face, followed by a 3 μm thick coating deposited using physical vapor deposition (PVD) with a cathodic arc method. Experiments compared coated, textured, coated-textured, and chip-breaker tools against an as-received WC-Co control under dry, wet, and minimum quantity cutting fluid (MQCF) conditions at a feed rate of 0.2 mm/rev. Surface roughness (Ra) was measured using a contact profilometer, and tool morphology was analyzed via optical microscopy (OM). The TC tool under MQCF achieved the lowest surface roughness (Ra = 1.313 μm) and friction coefficient (μ = 0.19), which can be attributed to reduced tool-chip contact and enhanced fluid penetration through microchannels. OM confirmed minimal wear on TC tools. This approach significantly improves tool life (up to 25 % reduction in wear) and surface quality, offering a cost-effective solution for the precision machining of aluminum alloys.