تاثير نرخ انجماد و عمليات بهسازي بر ريز ساختار تركيبات بين فلزي آلياژ ريختگي A319

Effects of Cooling Rate and Modification on Microstructure of Intermetallics in A319 Casting Alloy

In this research, the effects of cooling rate and modification on the microstructure of A319 alloy containing 1% wt Fe have been investigated. Experiments were conducted with unmodified and modified alloys on the fluidity test strips in permanent cast iron mold with various thicknesses (1, 3, 5, 7, 9 and 12 mm). To modify, A319 alloys were prepared by the use of modifiers elements (Mn, Cr, Co and Sr). The fluidity of all samples was determined and the relationships between modification, casting thickness and fluidity have been investigated. The results showed that modification has changed the morphology of needle-beta phase to Chinese script-alpha phase and improved the fluidity of the alloy. Further results showed that increasing cooling rate improves the modification. Sr addition was found to be more effective in modification of the microstructure compared to other modifying elements.