Studies on aggressive mass finishing for metal component remanufacturing

• Main Author: Ho, Jeremy Weng Keong
• Other Authors: Yeo Swee Hock
• Format: Thesis-Master by Research
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering::Mechanical engineering::Kinematics and dynamics of machinery
• Online Access: https://hdl.handle.net/10356/172925
• Institution: Nanyang Technological University

This thesis introduces a novel vibratory finishing machine designed for the aerospace industry, featuring a domeless, circular vibratory finishing bowl. The study aims to explore the machine's advantages over conventional dome vibrators, particularly for annular components, with limited existing literature in this area. The investigation focuses on the domeless-type vibrofinishing process, analysing its performance based on varying component-machine sizing and orientation. Results indicate that airfoil orientation relative to the media flow has the greatest impact on material removal. The optimal position for surface finishing is at a 45-degree angle, resulting in the highest surface roughness improvement and material removal. Certain airfoil positions lead to reduced media flow and stagnation, negatively affecting the finishing process. The study also explores indirect media interaction, where media particles interact with surfaces not directly exposed to the primary media flow, contributing to material removal and surface finishing with approximately half the effectiveness of direct contact. Furthermore, the thesis three vibrofinishing techniques - domeless, dome, and trough – theoretically, experimentally, and economically. Theoretical analysis demonstrates the potential for more efficient processing with the domeless design, with an 80.5% increase in excitation force and up to 144.6% increase in excitation moment compared to the dome design. Experimental results confirm higher material removal in domeless vibrofinishing, while the trough process fails to meet surface roughness requirements. Cost analysis reveals significant differences in capital and operational expenses, with potential cost savings of 70.3% and 60.3% by adopting the domeless bowl to replace the trough and dome bowl, respectively. In conclusion, this thesis provides strong evidence for a domeless vibratory finishing machine’s advantages in material removal and surface roughness improvement. The experimental and theoretical analysis conducted demonstrates the potential for more efficient processing, higher material removal rate, and cost benefits when compared to the conventional designs.