Yield improvement: With simulation technique, the casting process and method are optimized in short time and also, the casting process is optimized there will be very lesser wastage thus it results in reduces the effective melting cost per casting

Porosity Analysis and Optimization of Casting Process Parameters using Simulation Software for Sand Casting

Umakant Suryakant Landage1, M. S. Harne 2 1 PG student, Mechanical Engineering Department, Government College of Engineering, Aurangabad. 2 Associate Professor, Mechanical Engineering Department, Government College of Engineering, Aurangabad.

Abstract: Casting is the oldest manufacturing processes used to manufacture metallic components. Sand casting is mostly used casting manufacturing process because of its process simplicity of producing complex geometry with ease. Various casting defects have adverse effect on casting quality and productivity. The defects in the component are identified to be solidification shrinkage, gas porosity, blow holes, pin holes, cold shuts, unfiled riser, misrun and incomplete mould cavity. The reasons of defects are analyzed as either improper selection of process parameter or improper design of gating and feeding system. Many researchers reported that 90% of the defects in casting are obtained only because of improper design of gating and feeding system. The main objectives were to study the existing design of gating and feeding system, to optimize the gating and feeding system using casting simulation is helpful to visualize mould filling, cooling, solidification and to predict the location of internal defect in casting such as sand inclusions, shrinkage porosity and cold shuts, it can be used for troubleshooting existing casting and to develop new casting without shop floor trials. The mould is modified accordingly with the simulation results and metal is poured into it. The casting produced are observed and found to have no defects. Taguchi technique is used for optimization of the parameters and orthogonal array is used for experimental purpose. Taguchi orthogonal array reduces these number of trials and cost and save time and give accurate results and this result to prepare the sand mold and cast the product. Keywords: Casting, Defect, Simulation, Parameters, Filling analysis, optimization, method and design.

I. INTRODUCTION

Casting is the most economical processes in manufacturing industry to produce metallic components. Metal casting is the process of producing metal component parts of desired shapes by pouring molten metal into mould then allowing the metal to cool and solidify. The foundry engineer designs the gating and risering system for the casting. The time is spent in designing and redesigning the gating and riser system. It might take few days or up to several weeks, depending upon the complexity of the casting. Casting simulation process is developed from the methods which are useful to predict the defects and problems before the actual product of cast avoiding costly trail to prevent the defect. In the current scenario, the use of casting simulation software is increasing day by day in foundry industry and minimizing the shop floor trails to attain sound casting. The casting simulation technology has sufficiently matured and has become an essential tool for casting defect troubleshooting and method optimization.

A. Classification of casting defects 1) Filling related defects- sand inclusion, Blow holes, sand burning, misrun, cold shut. 2) Shape related defects- distortion or wrap, Mismatch defects, flash defects. 3) Thermal defects- Tears or Crack, sink mark, shrinkage. 4) Defects by appearance - cavities, discontinuities, Metallic projection, incomplete casting, defective surface and incorrect dimensions or shape.

B. 1) 2) Inputs for the casting simulation process Geometry of the mold cavity (3D model of the casting, gating channels and feeders) Thermo-physical properties (specific heat, density and thermal conductivity of the cast metal as well as the mould material, as a function of temperature). Boundary conditions (i.e. the metal mould heat transfer coefficient, for normal mould as well as feed aids including insulation, chills and exothermic materials). Process parameters (such as pouring rate, temperature and time).