Degree Name

Doctor of Philosophy


School of Mechanical, Materials & Mechatronic Engineering


The wide-spread usage of Nickle Aluminium Bronze alloy is observed for casting of components in the environmental applications. The reflection of endurance, corrosion resistance and extreme strength is emerged from an oceanic environment. The factors of nickel aluminium bronze are effective in demonstrating fracture toughness at high and low temperature along with a tensile strength. Friction stir process is an innovative technique used to enhance the performance of metals including aluminium, titanium, copper, nickel and steelbased alloys. Friction stir process is effective in modifying and controlling the microstructure in the surface region. It also assists in experiencing an enhanced mechanical property on the basis of rotating friction stir process tool. Objective: The main objective of this study is to explore the significance of optimization parameters for robotic friction stir process using Computer Numerical Control friction stir process. The study further aimed to investigate the hardness of microstructure elements of nickel aluminium bronze. By considering vibratory waves and corrosive medium, cavitation erosion and corrosion of Nickle Aluminium Bronze alloys were also analysed. Methodology: A Friction Stir Process has been used in order to analyse the influence of cavitation erosion and corrosion of nickel aluminium bronze. The robotic system was used to represent the low force technique on the basis of optimization parameters. The samples were acquired for mounting and polishing hardness, microstructural hardness, corrosion and cavitation testing. The samples were examined by using the optical microscope and SEM. The images obtained from these tools were used for analysing. Hardness testing was further computed through the acquired samples. The calculation and graph plotting were obtained by using a potentiostat apparatus. Nickel aluminium bronze specimens were used for the experiments with different chemical compositions. Results: The results for the microstructure hardness and cavitation erosion have been examined from the optimization parameters. The higher range of rotation speed (RPM) with low traverse speed (mm/s) leads to the highest surface hardness. A rotation speed of 3000 RPM with a traverse speed of 0.5 mm/s and 1 mm/s provide the highest hardness readings of 𝐻𝑉0.2 = 290 and 299 respectively.



Unless otherwise indicated, the views expressed in this thesis are those of the author and do not necessarily represent the views of the University of Wollongong.