Rheological study of the developed medium and its correlation with surface roughness during abrasive flow finishing of micro-slots

Abstract

Abrasive flow finishing (AFF) is an advanced finishing process employed for finishing macro- to micro-features of workpieces. Finishing improves the functioning of the components by reducing their surface roughness. AFF process uses a polymer-based flexible medium containing abrasive particles as a finishing tool. Medium used during the AFF process plays a vital role in deciding the final surface roughness on the workpiece surface. It is the medium properties in combination with AFF input parameters that decide the end surface roughness. Micro-features on the components are mostly machined with the help of processes involving thermal energy (electrical discharge micro-machining, laser beam micro-machining). This leads to the formation of hard recast layer on the micro-machined workpiece surface. Component size and hardness of the recast layer possesses a great challenge to the finishing processes. In the current article, an economic viscoelastic medium is developed for the finishing of micro-features and its detailed rheological study is carried out. Later, experimental study of the AFF process during the finishing of micro-slots (440 ± 10 µm width) in surgical steel is performed. Developed medium successfully finishes the micro-slots with an initial surface roughness of 3.54 µm to a final surface roughness of 0.21 µm (94.07% reduction in surface roughness).

Keywords:

• Abrasion
• abrasive
• finishing
• micro-slots
• rheology
• roughness

Additional information

Funding

The authors are thankful for the financial support provided by Board of Research in Nuclear Sciences (Project Number: ME/P/MRS/02), Department of Science and Technology for their Technology Systems Development Program (DST/TSG/AMT/2015/619), Defence Research Development & Development Laboratory (CARS Project).