OPTIMIZATION. OF VARIABLES FOR DIMENSIONAL ACCURACY AND SURFACE FINISH FOR SMALL SIZE G.I. CASTINGS PRODUCED BY GREEN SAND MOULDING. BY USING - TAGUCHI METHOD

Abstract

Green sand moulding process produces by far the largest quantity of castings, whatever the metal poured into sand moulds. Among the sand casting processes, moulding is often done with green sand because of itsgreater flexibility ti as a production process, and least costly method of moulding. Now-a-days quality concept is changing towards the design phase of the product and process i.e. controlling the quality at design stage instead of controlling at the manufacturing stage. This is the underlying idea of off-line quality control. One of the most comprehensive and effective system of quality control is Taguchi's method, which aims at achieving consistently quality of the product. The objective of present work is to optimize the process variables like sand grains size, percentage of bentonite, percentage of water and pouring temperature, for the dimensional accuracy and surface finish of gray iron.,~~ • The composition of gray iron is (C = 3.9% Si = 2.24%). The specification of 5 .q grey cast iron is ASTM — A48, which is extensively used for general purpose and thin section small casting. The experiment works carried out by using L8 (27) OA. The main effects of process parameters on the quality characteristics have been plotted. The predicted optimal values and ranges of the quality characteristics have been