Investigation of ablation studies of EPS pattern produced by rapid prototyping

ABSTRACT

Expanded Polystyrene (EPS) patterns are used in Evaporative Pattern Casting (EPC). The cost of EPS pattern-making through moulding cannot be justified for small batch production. As 3D printing or Additive Manufacturing (AM) is suitable for small volumes, several efforts have been made to develop these machines for EPS including Segmented Object Manufacturing (SOM) of the authors. EPS is typically processed through ablation or traditional machining, the former using hot tools in the form of profiled axisymmetric shapes, blades or wire. The efficacy of SOM machine relies on the performance of the individual sub-systems, so in the present work, the ablation studies of hot wire slicing of the machine is performed. The kerfwidth and surface roughness determine the quality of the pattern produced by ablation. The objective of the paper is to investigate the ablation process by introducing novel mathematical model to predict the kerfwidth for different power inputs and feedrates, which is further validated with experimental data. Subsequently, an empirical relationship is established to predict the surface roughness (R_a) of the sliced surface by performing regression analysis of collected experimental data. The different cutting zones have also been classified, which gives an overall understanding of slicing mechanism. The average error in surface roughness prediction is found to be around ±10%. With the help of these models, the SOM machine can produce better quality EPS patterns in terms of kerfwidth and R_a value, which finally depicts the quality of final casting produced by EPC process.

KEYWORDS:

• Expanded polystyrene
• rapid prototyping
• evaporative pattern casting
• hot wire slicing
• ablation

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Ranjeet Kumar Bhagchandani was born on 22 July 1987. He is presently a Research Scholar in the Department of Mechanical Engineering, IIT Bombay. He completed his M.Tech from IIT Roorkee and B.E. from M.B.M. Engineering College, Jodhpur. His research interests include Rapid Prototyping and Manufacturing, CNC, Manufacturing Automation and Characterization of Materials. Email: [email protected]

Sajan Kapil was born on 17 July 1989 and is presently a Ph.D. Research scholar in the Department of Mechanical Engineering under the supervision of Prof. K. P. Karunakaran, IIT Bombay. He completed his M. Tech from IIT Guwahati and B. Tech from G.B.P.E.C. Pauri. His research interests include Rapid Manufacturing, Functionally Gradient Objects, CNC and automation, Finite Element Method and Nonlinear Vibration. Email: [email protected]

Pushkar Kamble was born on 13 February 1992 and is presently working in Rapid Manufacturing Lab at Department of Mechanical engineering, IIT Bombay under the supervision of Prof Karunakaran. He has completed his M Tech from National institute of technology, Warangal and B Tech from Sinhgad College of Engineering, affiliated to Pune University. His research interests are Multijet Fluid Dispensing, Ice 3D Printing and CNC. Email: [email protected]

K. P. Karunakaran is an institute chair professor at the IIT Bombay, and has been teaching and researching in the areas CNC technology, rapid manufacturing and computer graphics from last 22 years. Prior to this, he worked in Hindustan Aeronautics Limited for about nine years. He was a consultant to Mercedes-Benz Technology Centre in summer 2000 and has been associated with Fraunhofer institutes and TU Dresden since 1998 as a Humboldt Fellow. He has been a Visiting Professor in the University of Metz and Ecole Centrale de Nantes. He developed Magics’s “OptiLOM”, a pre-processor for LOM-RP, in collaboration with DaimlerChrysler and Materialise. He is presently developing two RM processes, “Hybrid Layered Manufacturing” and “Segmented Object Manufacturing”. Email: [email protected]

ORCID

Ranjeet Kumar Bhagchandani http://orcid.org/0000-0002-6317-7028