A New Environmentally Friendly Chemical Mechanical Polishing Method Applied for Surface Finishing Ti-6Al-4V Alloy

Abstract

A new eco-friendly slurry has been developed for the chemical mechanical polishing process with a solution of malic acid, deionized water, and an oxidizing agent hydrogen peroxide (H2O2). The surface quality of Ti-6Al-4V workpieces with the proposed chemical mechanical polishing slurry with optimal parameters include oxidizers (H2O2), colloidal (SiO2) slurry, and deionized water by weight 8%, 45%, and 47% respectively, the pH concentration is adjusted 4 through the malic acid content present in the slurry. Experimental results obtained with the proposed chemical mechanical polishing method show a more improved surface quality than previous studies when applying for polishing Ti-6Al-4V alloy. The developed chemical mechanical polishing method's polishing results under optimal conditions obtain an ultra-fine surface quality with Ra = 0.696 nm over a measuring area of 53×70 μm 2 . X-ray photoelectron (XPS) and electrochemical measurements were used to study the chemical reaction mechanisms in the proposed chemical mechanical polishing process. The chemical mechanical polishing processes for the surface of the Ti-6Al-4V alloy workpiece with the H2O2 oxidizing agent showed high suitability with the reactants formed on the surface such as Ti, V, and Al oxide. With the proposed oxidant and the established chemical mechanical polishing slurry, the feasibility and surface quality of the super smooth Ti-6Al-4V workpiece formed after polishing were demonstrated. The established chemical mechanical polishing method shows high applicability in environmental protection and Ti-6Al-4V alloy ultra-precision machining industries. INTRODUCTIONAmong Ti alloys, Ti-6Al-4V alloy is the most common and also one of the most important engineering materials in Ti alloys [1-3]. Ti-6Al-4V alloy is widely used in many different industries such as medical equipment, sporting goods, petrochemical, aerospace, automotive, and many other industrial fields. Due to the relatively low density of Ti-6Al-4V alloy and high biocompatibility, chemical corrosion resistance and high strength [4,5]. With outstanding fatigue strength at high temperatures, Ti-6Al-4V alloy has been used in gas turbines in the aerospace industry with heat resistance up to 600°C [6,7]. With the parts subjected to temperature and cyclic rotational loads, the scratches caused by machining _____________

A Novel Circulating Abrasive Flow Strategy Using Circular Halbach Array for Magneto-Rheological Finishing of Ti-6Al-4V

“…Surface finishing of titanium alloys has become a focal point of research, particularly with its diverse applications in aerospace, biology, chemistry, and medicine. The distinctive characteristics of Ti alloys, such as low toxicity, exceptional corrosion resistance, commendable toughness, and high tensile and yield strength, underscore their significance [18][19][20]. However, machining Ti alloys poses inherent challenges due to their high chemical reactivity, low thermal conductivity, and low elastic modulus [21,22].…”