چكيده به لاتين
Abstract:
Functionally Graded Material (FGM) has been developed widely in recent years. In this research, due to produce cylindrical FGM with high hardness and wear resistance at surface and enough toughness, two hypoeutectic (A319 as core) and hypereutectic (A390 as surface) alloys by cast-decant-cast (CDC) method has been used and microstructure, hardness and wear behavior of final product has studied. Image analysis showed that volume fraction of Si changes gradually at the interface of these two alloys and increases from hypoeutectic to hypereutectic side. Hardness values for hypoeutectic, interface and hypereutectic alloys have obtained 73, 85 and 113 HB respectively and micro hardness values also showed that harness of interface gradually has increased. Dry sliding wear tests have been conducted using a pin-on-disk machine under different normal loads of 15, 30 and 50 N and at a constant sliding speed of 0.15 m/s and sliding distance of 1000m. The results showed that wear rate of hypoeutectic alloy is 22%, 32% and 2% more than hypereutectic alloy respectively and at load of 50 N wear resistance of hypereutectic alloy decreases. Wear mechanism of two alloys is adhesive wear with MML formation.
Keywords: Functionlly Ggraded Materials (FGM), Cast-Decant-Cast (CDC), A390, A319
