SOME INVESTIGATIONS OF SURFACE FINISH OF GREY IRON CASTING

Abstract

Subject of surface finish in metal casting industry has relevance when we talk of precision castings. Any geometrical inaccuracy arising out of non confirmity due to metal penetration, mold wall movement mold deforma. tione. Other surface defects, a faithful reproduction of contours has to be ensured before applying the concept of surface finish. All these connected issues had to be studied for the above mentioned reasons. After all the distinction between the surface finish and geometrical inaccuracies is a difference of degree only and not of type. In the event if geometrical inaccuracy has been introduced measurement of surface finish has no meaning. Mooted from these considerations, it was decided to analyse the entire issue of mold behaviour, mold testing, mold material investigations etc. Detailed investigations were carried on various testing methods to simplify the testing procedurewhich in turn would ensure a desired objective function. It was felt that Differential thermal analysis has a big potential to predict the mold performance at elevated temperatures and could replace time consuming costly methods, hence detailed investigations were undertaken.