Pathya Rupajati, a doctoral student in the Mechanical Engineering program at the University of Indonesia, researched the development of welding joining processes. This idea was articulated in his dissertation titled “Development of Micro Friction Stir Spot Welding (mFSSW) Joining Process on Dissimilar Metal Brass CuZn30 and Aluminum AA1100.” The dissertation was presented at the public defence of Pathya Rupajati’s doctoral promotion on January 10, 2024.
Pathya stated, “Friction stir welding (FSW) with a melting temperature below the base metal’s melting temperature is commonly used in manufacturing, automotive, aerospace, shipbuilding, and electronic industries. Currently, FSW welding is still in the development stage because the FSW process occurs below the melting or solidus temperature of the workpiece. Other joining methods are derivatives of the FSW process, namely micro friction stir spot welding (mFSSW) and micro two-stage refilled friction stir spot welding (mTS-RFSSW).”
“From the research, it can be concluded that the lap shear force and cross tensile force are highest with a combination of 7s dwell time and 0.75 mm plunge depth, measuring 400 N and 85 N, respectively. It was also found that mFSSW joining using a nickel interlayer on dissimilar metals, brass CuZn30 and aluminum AA1100, with the same process and response variables as mFSSW, showed an increase in lap shear strength accompanied by higher displacement compared to the joining without an interlayer,” continued Pathya Rupajati.
“The development of this welding process is expected to contribute to the advancement of knowledge, especially in the field of welding. This dissertation can also be a literary contribution to the development of mFSSW dissimilar metal joining processes,” stated FTUI Dean, Prof. Dr. Ir. Heri Hermansyah, S.T., M.Eng., IPU.
At the end of the defence, Pathya Rupajati achieved a GPA of 3.87 with the predicate “Very Satisfactory.” Dr. Pathya Rupajati is the 103rd doctoral graduate from the Department of Mechanical Engineering and the 530th from FTUI. The doctoral promotion defence for Dr. Pathya Rupajati was led by Prof. Ir. Mahmud Sudibandriyo, M.Sc., Ph.D., with Prof. Dr. Ario Sunar Baskoro, S.T., M.T., M.Eng as the main supervisor and Prof. Dr. Ir. Gandjar Kiswanto, M.Eng, as co-supervisor. The examination committee included Prof. Dr. Ir. Winarto, M.Sc, Prof. Dr. Ir. R. Danardono A.S, DEA, Prof. Dr. Ir. Triyono, M.T., Jos Istiyanto, S.T., M.T, PhD, and Sugeng Supriyadi, S.T., M.S.Eng., PhD.
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Faculty of Engineering, University of Indonesia
