EFFECT OF PROCESS PARAMETERS ON MECHANICAL PROPERTIES OF THE INVESTMENT CASTINGS PRODUCED BY USING EXPANDABLE POLYSTYRENE PATTERN

The present study is concerned with the investigation of mechanical properties of A713 alloy castings produced by investment casting process using expandable polystyrene as the pattern material and the plaster of paris as the mould material. Experiments were conducted as per Taguchi’s L9 orthogonal array. Castings were made under the constraint of different process parameters like mould firing temperature, pouring temperature, firing time and mixing of silica sand of different grain fineness numbers to investigate their effects on the surface hardness, impact strength and tensile strength of the final castings. The variations in the trend of the aforesaid mechanical properties were observed and it was deduced out that high mould firing temperature, higher pouring temperature, maximum firing time and high grain fineness number significantly reduce the mechanical properties of A713 alloy castings produced by the above process.